20 Burst results for "Cepheids"
The Secret History of the Future
"cepheids" Discussed on The Secret History of the Future
"You could explain project Texas to me. So project Texas is a huge initiative that people at TikTok and by dance have been working on for well over a year now. And the theory behind it is that TikTok and ByteDance want to find a way to basically sequester U.S. data in secure data centers within the United States and have that data manage and overseeing by a U.S. based team, which they call U.S. DS that used to be U.S. TS. And the idea behind this is if they can essentially create a sort of hermetically sealed U.S. unit that ByteDance can continue to own TikTok, but only people who are sort of approved to be in this U.S. unit will have access to U.S. user data and they now say control over recommendation systems in the United States. Oh, how the algorithm says this is what you see. Right. They hoped that if this was a successful project that they would then replicate it elsewhere that they would do this in Europe, but they could do it in other parts of the world where data protection is an issue for regulators. Lawmakers, for their part, did not seem to be buying into this plan on Thursday. Let me just start out by saying mister Chu that I don't find what you suggested with project Texas and this fire will that's being suggested to whoever will be will be acceptable to me. In other words, the I still believe that the Beijing communist government will still control and have the ability to influence what you do. And so this idea of this project, Texas is simply not acceptable. Well, I think there are sort of two challenges with project Texas. One is that if the people who are in the U.S. DS entity still report into ByteDance on some level, if those people are determining whether they have jobs, their salaries, whether they get promoted, et cetera, then even if people bite dance don't have access to that data, if they're subordinates do. They're sort of a structural problem with them saying, no, I can't give you boss this data that you asked me for. And it looks like TikTok and by chance have considered some other ways to address that, including making the fiduciary duty different than just like a straight reporting line. The other issue with project Texas, I sort of alluded to before, TikTok was built as one of many ByteDance apps. It was built on ByteDance's sort of tech stack. And built in ways that sent data all sorts of places all the time. And none of that is nefarious. It's just like the backend at meta or the back end at Twitter or anywhere else, there are dozens and dozens and dozens of internal tools that send data from here to there to power this monetization tool or that analytics dashboard. And it's just like how the app and the company runs. And the challenge of identifying every place that private or protected user data is flowing and then make sure that every endpoint doesn't provide access to another part of the company that previously did have access to this data, but now shouldn't is like really, really hard. And the challenge of making sure you've got them all is very scary. It's sort of like proving a negative. So even though shochu is saying U.S. DS employees would report to an independent board and there'd be a fiduciary duty to the U.S. government and all of this stuff like that might not stop the data cockroaches. Well, there are two things. One is just like, have you caught all of the little holes that the data cockroaches might go through? And theoretically, you can do that. It's just really hard because they're very conniving little cockroaches. But I think the other question is more structural. If ByteDance, the company that at the end of the day owns the U.S. DS entity has to comply with Chinese law and thus could theoretically be forced to turn over information, is there a sort of intermediary structure hermetic ceiling with different fiduciary duty or whatever else that you can come up with that stops ByteDance for being able to have access to that information and then turn it over to the Chinese government. And the fact that CFIUS has come to the point where they're demanding a sale seems like they've answered that question in the negative and said no. I think TikTok is still despite this apparent demand from CFIUS trying to make the case that the answer to that question can be yes. And that's sort of interesting to me and this moment who is showed you trying to convince right now is he talking to CFIUS by talking to Congress the way that I sometimes talk to my boyfriend by talking to my cat, like it's that what's happening, I don't understand who he's trying to convince right now. Is it CFIUS or is cepheids at a point where they are just not going to accept anything other than divestment? And if that's true, we'll talk to Congress even help. When we come back, would a TikTok ban violate the first amendment? This episode is brought to you by sacks dot com. Sacks dot com editors are always tracking the top styles that are trending right now. Tailored blazers and midi dresses are selling out at sacks dot com, especially from brands like Veronica beard and the row. And Zach dot com editors are seeing lue's oversized tote on the streets of New York, Milan, and Paris. 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Bloomberg Radio New York - Recording Feed
"cepheids" Discussed on Bloomberg Radio New York - Recording Feed
"I von Bloomberg dot com and on the Bloomberg mobile app or check your local cable listings. Broadcasting 24 hours a day at Bloomberg dot com. On the Bloomberg business app. And at Bloomberg quick take. This is Bloomberg radio. Powell delivered this very clear message that the fed is going to do what it takes to get inflation down, even if that means pain for businesses and households. We think it's good that the fed is doing what it's doing. It's on the case. It's going after inflation. If we really get weakness if we get jobs going down, they will have to backtrack. We certainly haven't seen the earnings collapse that many others have predicted. So right now, increased volatility, it will be a September to remember, but I think we will get through this okay. This is Bloomberg surveillance with Tom Keene, Jonathan farrow, and Lisa Abramovich. ELISA has emailed Neil to tell him stocks are higher. Just to find out what he thinks about that. Life from New York City this morning. Good morning, good morning for our audience worldwide on cepheid and radio. This is Bloomberg surveillance alongside Tom Keane and Lisa rabbit some Jonathan farrow stocks bouncing back up 8 tenths of 1% fascinated conversation with a Minneapolis fed president Neil kashgar in our colleagues Tracy alloy and Joe Weiss and Tao. The fed president Tom was happy to see the stock market reaction to chairman Powell and Jackson hole over the weekend. Yeah, he was. I mean, there's going to be a lot of that in kashkari, you know, they're all different. He can talk the line. He wants to talk, but I think it's very, very typical to the back of the economic textbooks, John, but the markets matter
Scientific Sense
"cepheids" Discussed on Scientific Sense
"Once the data get more accurate and and other affect school will out now. The we won't have a thousand galaxy threat. We might have a thousand stars per galaxy. But we're not going to get to the point of having a thousand galaxies so But we will get to the point. Where i think statistical uncertainties will be very small and again it's up to us to reduce systematic effects but the increase in sensitivity the wavelength coverage and the resolution will allow us and the different techniques will allow us to do now if we have a disagreement so your earlier question will we need the cepheids. We can't predict what will happen. But if the cepheids the tip of the red giant branch ultimately gravitational wave sirens. Which i think is a method of the future. There's only one object right now but if we had three or four measurements that all had quoted precisions inaccuracies at the one to two percent level. I think we would be confident that we had a robust overall measurement. And that's what we did in key project. We had five different methods a secondary methods and then we also use the tip of the red giant branch to test cepheids in our library stars And so we could get an overall estimate of the systematic effects if you have only one measurement coming back to why said we started to do. The tip of the red giant branch is with cepheids. We'll never know alone. But if we do get convergence. I think we will have confidence. If we don't were we will continue to learn. We just don't know yet where it will end. Yeah that that makes a field area. So i didn't so so in conclusion i want. I want you to take a little bit For dental public thing about cosmology seems like be. We have a long way to go. We have dot doc energy that's ninety fighters it's still a lot about it. Because y- these measurement areas that we see from different methodologies that if some clues as to something might be missing vk neighbor to bring gravity into unified theory. So so. so maybe we will be. Let's say ten fifteen years into the future. I would ken fifteen years into the future. We will have Settled these issues. Now there are other hints that there may be cracks in the cosmological model but there may be the two sigma level. there's no claims of four to six sigma level effects but there are so many things coming on the horizon there. The extremely large telescopes. Like the giant magellan european telescope and and the and so on And does will allow us again to open up new frontiers and and really make progress. I think on on questions about dark matter and dark energy and The guy european satellite the parallels satellite. Those measurements are getting better and better with time and those will continue to improve. We've been discussing. James webb and that will get better. I think what we really need is a theoretical breakthrough. We're not going to solve. We're not going to understand what the dark energy is without some new idea that you don't have at the moment. I i still find myself wondering could we might not be fifteen hundred fifteen years from but fifty years or one hundred years if we look back. Are we asking the right questions Midi were not. Maybe we've taken a slight detour and in our picture of the universe will be very different but the way we will think ultimately determine that is by continuing to get better and better data and New ideas will surface that That things may lock into place in a way that that were at the edge now our understanding which always makes it an interesting field and it's the the.
Scientific Sense
"cepheids" Discussed on Scientific Sense
"So Yeah as i said if if anybody had ideas about where this could be useful I i'm not an expert in a and i i don't immediately see where it would come in but it should be interested to hear. Sounds like you let me get a lot be desert if james met dysfunctional and and doing so if lease win yes ben james. I have the optimistic here. James that is functional and taking measurements. They get knocked. Data said of of the jain stars and batch sit of the school. I would be great. I mean you know if you have what would you. What would you say. The numbers as tulsa data points That point you'd have sort of selfish and co strain on then you end up so i think this really will allow us to to say is this real or not whether we get one percent accuracy because of effects that again unknown systematics. It's unfortunate but not surprising that it it usually something that is. You're not even thinking about that is comes to get you in the end. And so when we were trying to solve the factor of to debate with the hubble constant and cepheids there were things. Nobody had corrective for reddening before That time or slightly before we got cds on the ground. We started to investigate this. Nobody had paid attention to the middle of the issue. And it wasn't possible to make those measurements because when you had a factor of two uncertainty couldn't it was in the noise and then as is our measurements improved to the ten percent level. We could measure fifteen percent effects or And i think as we pushed down now to one or two percent where we want to be. They're going to be other things that we will be able to measure for the first time that right now we have no hope of doing so again. It comes down to systematics but at least we be able to isolate those kinds of effects..
Scientific Sense
"cepheids" Discussed on Scientific Sense
"And that will help us. A lot and I unfortunately for the cepheids because cepheids a relatively blue stars. What in terms of Discovering cepheids it's best to do that where the amplitude of the stars are largest. they're in their brightness. But in the infrared the amplitude are really small so discovering new cepheids is not going to be one of the things that james webb will do well that hubble has been the perfect sephia discovering machine. Because it's sensitive in optical where the variations are largest will help us in terms of of measuring more accurate luminosity so the galaxies where we already have discovered cepheids but not as As helpful as it will be for the red gibe region in terms of discovering new objects at greater distances but mathematically you can show that people read joined ryan is less noisy sitting you lease deal gore the city of trump anymore. I mean Isn't your methodology. Sort of passing. That will written radio. I think ultimately the tip of the red giant branch is going to be What will become the best standard. I think having different Method well so if we can Show directly there is a problem with either crowding or meddling in principle. We can correct. I mean we will have better data and we'll be able to see how we do The other advantage. Of course the tip of the john enters you need only a single observation to get the measurement of the luminosity of the store with the cepheids we need at least a dozen observations to measure the periods and to determine the period luminosity relation. So it's much more cost effective in terms of telescope. Time particularly. That's important for james webb because it takes a long time to to salute to move this telescope to a target and So that that would be a very big challenge. For j w to measure cepheids with any kind of efficiency it will be much more efficient with took john branch. But i think it. Typically giant branch hasn't been studied for as long as cepheids but as we continue to improve the calibration. It's going to be very hard to beat it in terms of Ultimate accuracy because of the simplicity of the method. So this thinking video ultimate symbol. So can be put in some. Ai sort of curious speaks indira as as the james loop for style. If it finds a able to rent up ryan star you just take one measurement rate so it could almost sort of collect this data in an automated. So i'd like to understand better how it would have so few it you have to we. We have of course That go into our galaxy data set and and measure the luminosity and then the colors that temperatures of the stars and then So it's not. As if james webb james. Welcome to be serving the whole sky write. These are pointed observations and so we need to tell the telescope were two point..
Scientific Sense
"cepheids" Discussed on Scientific Sense
"This first test says. We'll wait a minute. There's not apparently afford cigna. Cigna effect with the tip of the red giant branch as has been claimed for feuds and and so even in the nearest galaxies we are seeing differences. And that says there's some systematic effect right. That's not new fundamental physics of the early universe. That's these galaxies are at a single distance. Stay they can only have one distance and if the cepheids tip of the red giant branch are giving different answers. There's some systematic uncertainty in one or both and we'd better understand that he fully claim that there's the disney fundamental physics acquired be of course is h nor is not a constant. It's cheating time we'll it is changing with time right. I mean that's with dark energy rate as a function orig- after time the the expansion university does change that that's certainly the case but local spatially in our local neighborhood which is what we're measuring with a the expansion rate today h not means time at t zero that that's what we're measuring in the cosmic microwave. Background measurements The required so these are measurements being made at the surface of last scattering and Redshift of eleven hundred and and then it's the model the cool dark matter. Lambda model that allows you to then infer what the expansion rate is today but it certainly has been changing time. We know that for each nope. You're messing from cnbc. Actually each note. A tiny zero. It's not it's not clear. Eighty thousand years after you bay. You have to have a model right so if you assume that. Lambda cd is correct. Then you can infer the expansion rate today And and so. When you do that into as i said the fits to the fluctuations that are being measuring temperature and polarization if you use a six parameter fit for a lambda cd model. It's an exquisite fit to those data you don't need any additional visits and so what's happened is so when you have that fit then you can say okay. What would expansion then rape beat today. Based on the lambda see the model and you get sixty seven so if it's If the local measurements are correct. That would say something's missing from the lambda. Edm that's worth that impetus coming from so we better be right new local universe to claim that there's this extraordinary new physics and and it's There've been many measurements now so not just a planck or w map but also measurements from chile and the south pole the act measurements and south pool s. t..
Scientific Sense
"cepheids" Discussed on Scientific Sense
"Navigator that a pension has been between c. B that as that seems to fit everything that feed now and that shooting sixty seven local measurements. Oooh something about or close to seventy is the bias. Selection problem is clearly get just looking at about two dozen samples right could be just unfortunately picked up two dozen observations that sort of give us a long data. Think i think statistically it's unlikely that it would be a ten percent effect. You could imagine that the couple percent affect your unlucky and you somehow the mean of your your sampled. It is biased in some way. But it can't explain the whole difference. I mean the difference between sixty seven and seventy four is nine percent and and that just as statistically incredibly unlucky unlikely so i don't think that will be the answer but you could also imagine there could be several effects that again the one percent level or two percent level of we discover that i mean i think the other thing to be said is some of these effects. Our co variant right. So if you're trying to measure cepheids and correct for the presence of dust. You need to filters to do that at least two. It's preferable you have more than that too correct for the reddening. 'cause changes the color of the star. You also need to correct for this metal abundance. A fact which is also a function of affects the color of the star and And then you have to worry about the fact that you're in these crowded regions in the spiral galaxies and crowding goes up towards the center. They're more stars in the center. The density of stars is higher. The metal abundances higher and the reddening is higher. So all of those exco in the same direction. So so you when you're trying to correct for those effects if you make an error say because you got the wrong luminosity of your star because of crowding then you get the reddening wrong and get them eliciting wrong..
Scientific Sense
"cepheids" Discussed on Scientific Sense
"You can determine the distance to your object but you need that calibration so for example be great if we could use type one a supernova without having to worry about cepheids or tip of the red giant branch at all but we only know the relative brightness is of type one a supernovae we we have to get an absolute calibration of the distance and the supernova here. Just too rare on to do that and we have no way of measuring relax for a nearby supernova so So so we have to rely on what we refer to as a distance ladder which has become much simpler. Since hubbell's time but nonetheless we still need to step out into the universe using nearby stars where we have geometric distances than the realm of the hubble space telescope where we can measure cepheids are typically red giant branch stores to compare with the geometric calibrations and then step out to type one a supernovae and then we can get out into the distant what we refer to as the hubble flow and the reason we have to go distant as because again galaxies are located in groups of galaxies. they they tend to interact gravitationally and so that it adds annoys peculiar velocity above and below the hubble expansion velocity so as you go farther and farther out this. This effective peculiar motion is much smaller relative to the hubble expansion. That's really a three step process. And and so we work very hard to try and make sure that the calibrations are consistent and that we're comparing apples with apples as we step out into the into the distant flow. But but i think that again is we need to be a careful that at each step we are eliminating the systematic errors. That could play. Gus that historically is you quoted before have been the bane of the extra galactic distance scale. This is the basic assumption means to be the standard candles and so we can't assume that the physics underlying them Available of the red star the physics underlying them is.
Scientific Sense
"cepheids" Discussed on Scientific Sense
"One that we've been developing using type of star carbon star. That will allow us to really get it. These questions of systematics James webb was bigger. It has more sensitivity. it has better resolution and and we can measure for the first time One of the systematic uncertainties in the separate distance skill has to do with the abundance of the cepheids. Themselves that is younger. Cepheids have been around longer there meet at a more process material. So the amount of medals in their atmospheres is higher and affects luminosity of the star. And that's been one of the big unknowns in the distance guilds were just before the project and the cosmic microwave background observations now. They're a value of the hubble constant is measured to a precision of less than one percent better than one percent which is extraordinarily. And we haven't done that yet with our local measurements because of these kinds of systematic uncertainties. So james webb is going to let us really get at some of these remaining difficulties and it remains a really exciting possibility that there's new physics but we better be sure that we've gotten on top of this systematics and so that that's why i'm really excited about what's coming up. It's a whole new world opened up by james webb. Talk in detail but before we get and just sort of go back so the city measurements as you say. A hubble had a flight thousand memoir and and then event- from your sort of fifty to one hundred estimate just average them into the dance with seventy five and then be metal vashem's the audience She age begin. Listened less by sort of staying there right the expectation still from a severe Measurements seventy four. Seventy three seventy four. That's right and then Cbs say we can't be precise measurements. That's coming at sixty seven and then what you have been working on four past several years. They're the red giant the tip of the rain giant lange measurements. These things that. I guess it just let less. Noisy measurements is the way to think about. Yeah i think that's the way to look at them. So these are evolved stars low mass stars and the cepheids are young stars and so we have no choice but.
Scientific Sense
"cepheids" Discussed on Scientific Sense
"Would be different. Yes taking measurements of innovative. Well the stars in the milky way will be bound to us wait long enough darker she will But yeah we would see the night. Sky still fill stars but our understanding of the the greater universe and in galaxies within it. will different constant h not. I mean you spent many many decades missing the hubble constant. So what does flustered at tent at doing this. So i want diplomatic analogies that that wasn't the was the first one valuables was last attempt. The sepe is go. Will you back in fact. Edwin hubble jozef variables when he first discovered the expansion. He only had a handful of galaxies that he could measure cepheids in the telescopes that point he he couldn't see much farther so he used bright stars and what came to be known as h. Two to to make his famous diagram. And so cepheids have been used now for almost one hundred years. The cnbc measurements are of course are much newer than that. But what had happened was that based on the measurements hubbell. I measured a value of the hubble constant of five hundred coloma's per second per mega parsa. In the diagram you're describing it's slow of that correlation between velocity and distance and that value settled down to about in a range of fifty to one hundred and and so there was a factor of two uncertainty. That people were arguing about for decades and then in when the hubble space telescope was launched a eyelid of a what was called the hubble key project to to use fema's measured with the hubble space telescope get us above the earth's atmosphere which allowed us also with the availability of ccd detectors digital detectors instead of the photographic plates available to hubble to measure the hubble constant much more accurately so we use cepheid variables to calibrate five different methods including these type. One a supernovae that we use today to to measure the hubble constant and we got a value of of seventy three at that time and it's remained pretty steady The sapphire calibration comes out high. And then the microwave. Background measurements got better and better in the last couple of decades and they are so precise in the way that you can measure fluctuations in temperature and now also the polarization of light from a remnant radiation from the big bang. And if you assume a model a what. We call our standard model. Now which provides an exquisite fit to the fluctuations in those temperature polarization measurements. Then you can infer the hubble constant today and when you do that you get a value of sixty seven so there's this discrepancy between the cepheids and the coming from the the cosmic microwave background observations. Which if it's real. It would imply that there's some fundamental physics. That's missing from our standard model. And so the the question now is. Is this a real discrepancy. Or could there be systematic uncertainties that we haven't yet identified. That could explain the difference and so our group used these red giant branch stars method using the tip of the red giant branch. We call it to independently calibrate the supernovae not using cepheids at all and we initially expected that either we would agree with the cepheids or would agree with the microwave background and we found ourselves right in the middle And in fact there's no discrepancy statistically speaking with the microwave background observations however it's also in relatively good agreement with the cepheids so Where i become really excited is. We're about to have the launch of james webb space telescope in a couple of months now and that will allow us. We've just been given time on. On james webb to measure distances using not just cepheids not just with their agenda ranch but in the same galaxies us both those techniques and a third.
Thoth-Hermes Podcast
"cepheids" Discussed on Thoth-Hermes Podcast
"Decided to put all their astronomical knowledge and really their knowledge of the universe everything they need onto bills and one was built of brick which and the other was built of stone on the wall was built of stone in case a flood destroyed the brick and on the pillow was risen all his knowledge. Now this story doesn't appear in the by over josephus expected to be understood and he's really saying to the romans providence. The protect the has provided a conduit a passage of knowledge from the earliest times to those who survived the flood. Anybody then says the end of this account. Everybody knows what happened. Of course there was the flood he says this one of the pillars remains to this day in the land of syria and that's an anglicized version of the word. He uses which is in greek which is mean. Well get this the second now. They english translation of this passage. That has become probably. The most influential in scholarship was translated by isaac nuisance colleague william christian and he took away a silly ad some Say the ad as it's written in greek. He thought it meant syria and he presumed that the pillow being fed to was actually long directed by theros as australia's and so he cast a historic downtown. Whether the pillar referred to by josephus contract the wisdom was wrong. Also because he followed herodotus. The fifth century is greek historian. And he'd go wrong as well because the ellas he refers to that he thinks ceska is as equals. They were in fact from minor kings who robot the and so in. It doesn't really know but the point is they mortgages tradition weather suviving. Bill was in syria. Now if you get this the reason this era has come about. Because wister was using the latin version of josephus which was published by cloven in the early sixteenth century and frohmann puts it in basic good lassen than it was in the land of interior acilia but if you go to the earliest greek russian own. Wish frozen is intake. As soon as i got my head son syria sue yet and this area declined syria at all. Because they're they're quite a few. I can think of nearly half a dozen references to silently add referring specifically to stop. Okay what the word means. Siad is the serious worshiping lamps. And which are the serious worshiping labs. Of course we know that serious was of central influenced to egypt and so the first part of the book is led slow case. Can we location pillow. The lost pillar later called a pillar of enoch. That's what i was going to ask. Why did get into name of enoch into that because we know know of course on the bible but also in a very particular context especially in in in the western esoteric tradition right. Well this whole project came about. Because i was contacted by professor gaby boca genie of the university of michigan around. Something called the the inuk. Seminar which is an international body of scholars who study set second temple judaism and the origins of christianity. And the book hawk. As you probably know that famous book being Is in fact the most reproduced book in the whole circle density scrolls. So the i was asked to do a paper for a four for the conference couple of years ago in florence. I suppose to do the masonic the masonic cream sonic reception of the book amino and that was great for me. Because i'm fascinated by the book being written about it. In my book on john the baptist and here was opportunity to really get to grips with this problem not of enoch and freemasonry which is a certain parts of the book. The whole history of inaugural altogether and wii knock has been identified with hermes trice justice. And this is where. That's why we are on false. Hermes because as i thought was the greek god of magic rising as cooled by at george saint the is anti writer as the amaze and the second hermes is the one figure we knows he's tries to justice and by the tenth century hermes triesman justice become identified by arab scholars particularly within And so we that we have this whole combination. We got just see us talking about a cepheid pilla. We have a tradition coming at jewish. And we have the developed a hermetic arising and its influence as well and i thought well let's unpack. Let's try and unpack all. These trans am chauhan. They were and that was the real fascination. The book was to show and to revealing clearly. For the i think the first time the the real genesis of magic writings. I mean there are some major questions which none of the evidence will give us an answer to the real question here is did joseph get his bills story from a medic texts in aged or did the medic texan. Egypt writes about hermes transcribing tablets before the flood in the corey cosmic book in the korean cosmo sure in the mexican pricing. Did he get the. Is that an egyptian. Greg addiction copy from the inaugural with or does the enormous especially as interpreted. I just saved us in fact. Is it a steal from the great. How egypt. She's and so we really at the origin of medicine itself and inau quiz actually bound up with this. This mysterious question from the beginning and it is interesting. Skull is by the ninth tenth century. We're already saying well. We can't find the difference between inau saying must be the same. Only.
SpaceTime with Stuart Gary
"cepheids" Discussed on SpaceTime with Stuart Gary
"Spiker is latin for era of weight. Which virgo is holding a hand. Spike or alpha. Virginia's is the sixteenth brightest star in the night sky and he's both Spectroscopy binary and rotating absolutely variable a close binary system who stars a not eclipsing because apparent fluctuations in brightness because of changes in the amount of light emitting area visible to the observer spike's two main stars orbit each other once every four earth days and a so close their egg-shaped than spherical. I can only be separated by the spectrum. The primary is a blue giant variable beta cepheids star it undergoes mall rapid patients in brightness. These are caused by paul sessions of the staff. Surface thought to be caused by the unusual properties of i and temperatures of two hundred thousand degrees in the stellar interior. It has about ten times the sun's mass and about seven times. Its diameter the secondary star in spiker is smaller than the primary but still some seven times more massive than the sun and his three point six times. The sun's diameter tune to the north. Now and the constellation facilities the herdsman plowman. They will see the bright orange. Red star are terrorists or alphabetize just above the northern horizon. It's a red giant located. Just thirty six is away. Uploaded aging stars some seven point one billion years old nearing the end of its life. Why not much more massive than the sun. It's now expanded at some twenty five times the sun's diameter and will soon off outta gas. He's envelope as a planetary nebula revealing. Its white-hot still core a white dwarf which will then slowly cool of the of time another bright reddish looking star. This time in the east is the red supergiant antares meaning the rival of mas because of its appearance and location in the sky which appears to be opposite of mars in the sky is one of the biggest known stars in the universe. It's enormous eighteen times. The sun's mass ten thousand times. Its luminosity and eight hundred eighty three times. The sun's radius as we mentioned last month sky watchword place to the center of our solar system. It surface would extend out close to the orbit of jupiter despite being some five hundred fifty light years away. Antares is still the fifteenth brightest star in the night sky unlike the sun or tourists that did event antares will be far more spectacular. Antares is destined to explode as a core collapse or type. Two shoop inova when it does so sometime in the next few hundred thousand years it will appear as bright in the earth's sky's the full moon and be quite visible even in daytime. Antares has a companion antares. Be a special type. Blue white main sequence star within seven times the sun's mass and five times its diameter. antares is the heart of the scorpion in the constellation. Scorpius below scorpius constellation cemeteries the archer which points the way to the center of the milky way galaxy said deteriorates is commonly represented as a wing singapore pulling back on a boat which is aimed at taurus the center of the milky way galaxy and it supermassive black hole secretaries a star. Light the westernmost part of secretaries secretaries as stars twenty seven thousand light years away and has some four point three million times the mass of our sun it was in july back in two thousand sixteen that the solar system's berry center moved outside the sun where it will remain until twenty twenty seven berry center is the gravitational center of mass of a celestial system for example in our earth moon system the earth and moon actually orbit each other around a common center of gravity berry center at because the earth is so much more massive than the moon. The barry center is always inside the earth's radius if it were outside the earth's radius moon would instead have been classified as a binary planetary system like pluto and charon the solar system center of gravity or berry center usually located inside the sun's radius..
SpaceTime with Stuart Gary
"cepheids" Discussed on SpaceTime with Stuart Gary
"I love this podcast. Support this show through the acoss supportively. Joe it's up to you. How much give and there's no regular commitment. Just hit the link in the show description to support. Now this is space time series. Twenty four episode twenty seven coming up on space time. A changing doc energy necessary parkas solo probes swoops past venus at eighty seven thousand kilometers per hour and a new eye in the sky to monitor amazonian deforestation. All that and more coming up on space time. Welcome to space time with stewart gary. The universe was created thirty point. Eight two billion years ago and the big bang and it's been expanding of a sense that expansion which is still going on today sees the cosmos being stretched out in all directions like a balloon be inflated and thanks to a mysterious force code dark energy that rate of expansion is increasing. its call doc energy because physicists. Have no idea what it is. Hence the term dark as an unknown. They know doug edgy stronger now than what. It was billions of years ago. And that's affecting the rate at which the universe is expanding a figure called the hobbled constant and this is where things start to break down measuring the expansion rate of the universe in different ways gives you different results and that shouldn't be happening. Journalists can measure the hubble constant by using two methods the first observed things like cepheid variable stars in type one a supernova in the local universe. These give you an expansion right somewhere around seventy four kilometers per second. Make a pasig. A mega pass being million past six or three point three million light years it works because syfy variable stars pulsating that is expanding contract at a set rate based on their intrinsic luminosity and so they can be used as standard candles to measure cosmic distances. And so because astronomers know-how intrinsically luminous pacific variable star is because of its paul sation rate. They can determine how far away it is just like a row street lights all have the same brightness of the ones further down the road apiece dimmer than the ones nearest to you and the same goes for exploiting static code. Todd went a supernova. These stars all exploded about the same mass and so with roughly the same matter. Brightness and so like cepheid variables that can be used to determine cosmic distances the second method for determining the hubble constant uses measurements of the cosmic microwave background radiation in the primordial cosmos enough for the first atoms to form and for the first photons of light to escape about three hundred eighty thousand years after the big bang which according to measurements by the european space agency's plank spacecraft is much slower than the supernova value for the hubble constant. Just sixty seven kilometers per second per mega passaic. Assuming the lambda cold dark matter. Standard cosmological model of the universe is correct. Having two different for the hubble constant means scientists understanding of cosmology is missing something now a new hypothesis reported in the journal. Physical review d suggests the answer could involve a new type of dark energy doc. Energies a mysterious force which is causing the universes ready of expansion to accelerate when physicists calculate the expansion of the universe the basic relations on the assumption that the universe is made up of dark energy dark matter and ordinary matter until recently all types of observations fit it in with such model of the universe's composition of matter and energy is things are getting more and more precise that may no longer be the case. The study's lead author mountain. Sloth from the university of southern denmark says adding a new model of docket and g to the various calculations on the expansion of the universe results in less variation in the hubble constant sloth and co author flurry nadelmann suggests that. If there's a new type of extradite kennedy in the early universe would explain both the background radiation and supernova measurements simultaneously without contradiction. They are partha. Cise that in the only universe dark energy existed in a different phase. Slow says you can compare it to water when it's cooled. And it undergoes a phase transition to ice with a lower density in the same way dark energy in this new model undergoes transition to a new phase with low energy density thereby changing the effects of the dark energy on the expansion of the universe according to sloth in the intimate calculations the results add up imagine that dark energy thus underwent effaced transition triggered by the expansion of the universe itself. It's a face transition where the new face suddenly appear. And when these bubbles expanded collide. The phase transitions sloths. Is it's a very violent. Quantum mechanical process unaccustomed scale. This space time still the come. Nurses parkas solar probe is just undertaken. Its latest close fly by the planet. Venus sweeping above the venetian surface at eight hundred seven thousand kilometers per hour. And there's a new on the sky to monitor amazon in deforestation..
Scientific Sense
"cepheids" Discussed on Scientific Sense
"That you you referenced. And so we. We don't see a problem in the in the calibration. That's the wattage. Inda things mitt measuring things locally where we suspect the differences right now is in the range of distances that were covering with the hubble space telescope and so that that's where we're focusing. Our attention now is to try and understand. Where is that discrepancy arising and do the issues for example are mentioned a the reddening by and the chemical composition and the blending or crowding of stars in the cepheids. Is that in an issue. Kit could it be a systematic effect and And so that's what we're trying to understand right now. It makes intuitive than sites. You land in the middle but one save that. That sort of shows that the kevin quite gordon the systematics or the the measure of the errors chronically if measured the others more precisely soups are going to overlap. It could go either way I think your characterizing it correctly that we don't yet have There are issues with the uncertainties that could could Eventually you would end up in one place or the other right because we still overlap with the safin's it saying that. But where i agree with your statement is if you're underestimating your uncertainties that translates directly into saying that you have a larger a three sigma uncertainty with the microwave background. So the discrepancy with the red giant branch stars i think really is indicating that the cepheids he had uncertainties have been underestimated. And but as i said There are many things we can do now to improve those measurements. And i think this is not gonna take a long could take a century as with hubble to resolve. The this can be. I think in the next few years it can be resolved. I would imagine holding out that it's not going to solve because exciting cash. It's true. I think part parts of all of us probably want there to be something completely new and unexpected. But as i said you're gonna claim that then you really better have data. That you see is as bulletproof in to get there. I think we have a lot more to show and so in conclusion. Wendy if you look forward five years both in the in the program the carnegie chicago program that you mentioned. That's things going on. Do you think people differently. But what kinds of things that you're most excited about nasa mean independently of this one. This one add anything else that you you know. You really think that the might be might make a big leap toward. Yeah i think. I am really excited about this one. I think we have the prospect of learning something really new and exciting about the universe. I think what we have coming online in the next few years with j. w. s. key. We're gonna pro back into the earliest moments of formation of galaxies and black holes supernova in universe and the opportunity to to study planets exoplanets that are similar to the earth have similar masses and perhaps chemical compositions that could be actually measured in the atmospheres of these stars. That could be signatures of life. So one of the things that i did before coming to the university of chicago for for twelve years A lead the project known as the giant magellan telescope which is a twenty five meter telescope to be built in the andes mountains in chile and in one of the things that it will do have the capability of looking for a planets that have chemical compositions that might be biosignatures evidence of life. But i think what what also really intrigued me was the possibility with the new facilities like james webb space telescope for these giant telescopes that are being built also on earth. You discover things. You can't even anticipate now it just Questions you don't even know how to ask. And and so..
Scientific Sense
"cepheids" Discussed on Scientific Sense
"Has to be orderly matter right What i'm what i'm asking is it cannot be it cannot get source of error from. Let's dogma to. I know have been suggested as a candidate for it Is there any possibility that the dark magic could be clean. Interact with any of this measurements. No this this kind of measure would not be affected by looked for example of you have weakly. Interacting massive particles williamson the centers of cepheids Could they have an effect and no is just not a big enough to be observation. Really important for the type of measurement that that were carrying out it. It's more likely to be something having to do. For example with the chemical composition of the star or the evolution of the star. These stars are changing their characteristics. Says there is. We didn't about in detail. But the atmosphere is a steph are in motion they're actually pulsating and the stars are moving To hotter temperatures and colder temperatures as a looping back and forth and luminosity and temperature during the course of their evolution and so it may be that we just don't yet have That the stellar evolution on the effects of that evolution on the star. If you're trying to make a one percent measurement of the hubble constant which i should say the microwave background observations now are at a level of precision of one percent or better We're not there yet. With the local observations there too many astrophysical effects that preclude that kind of accuracy. So so. I think we have work to do those of us who are making these measurements based on astrophysical objects to demonstrate that these other kinds of effects have been Brought down to a level where we can say with certainty okay. This is a measurement of one or two or three percent or whatever. The number is and significant discrepancy. And so there are those who argue. Were already at the one percent level of mrs not even three sigma but five sigma and and i think. That's that's premeditated when i look at the data that just not what i see. I think we have a lot more work to get there. Good thing is speaking only. Go forward from here better. Well the good thing is we so there is a european satellite called guy making measurements. These parallels geometric measurements. That i mentioned earlier for one point. Eight billion stars in the milky way galaxy and some fraction of those measurements of course are cepheids and the red giants and there are other kinds of stars we use. I haven't even gone into but so our group working different stars again to try and get these issues of systematics..
Scientific Sense
"cepheids" Discussed on Scientific Sense
"It was the basis of the key project that we did in the nineteen nineties early. Two thousands the design of that project was to try and beat down the systematic errors. And we do know about the existence for example of astrophysical dust and that's where people like edwin hubble and others who followed went wrong systematically as they didn't crack for the presence of that dust they couldn't they didn't have the detector capability of doing it and that just they were stuck. And so we're using so for example. The saffy add variables. They are young stars. You find them in the disks of galaxies close to where they formed. So there's there's dust there and there's a they their atmospheres have dust in them. Depending on the chemical composition of star. And we don't exactly know what the effects of we can empirically try and put limits on matt but We have to worry about it. And then as i mentioned earlier one of the reasons why we went to the red giant branch stars is that they exist in the outer halos where the density of stars is lower. The cepheids. you're in the disk. And so you you get overlapping of stars when you're trying to measure the luminosity the halo literally. You can just see your stores isolated so you you put an aperture around it as it were. Add up the light in that aperture and you've got the luminosity actually do it in a more sophisticated way but in essence. That's what you can do. And then for the cepheids in your aperture you have. Many overlapping stars. Some are better than your saffy. it's making making the look redder in color. And and so you have dust which makes starlit redder. You have the chemical composition which of its high will make it look better and you have the overlapping or the crowding and images. So do worry that all those three effects are working in concert in in you have to have very precise measurements in order to disentangle those effects and so those are the kinds of things. Were looking at in detail and trying to understand. Is there something that we haven't yet been able to to measure to show unequivocally that there is is not a problem right it if we can take these air bars at face value. We're learning something really interesting about the universe. But if they're still something that you know just because these things are hard it's this are not simple measurements where we can go into a laboratory to make measurements over and over and change the experimental conditions. We have asked physical objects that are great distances. a faint and and And so these measurements are not trivial. So that my my own personal view at this point is that we still have more work to do and it'd be great if we could find his exit. Be extremely exciting. And if we're going to make extraordinary claim like that as carl sagan said you have to have extraordinary evidence and so we're working hard to provide the new evidence one way or another and it's important either way it turns out we opted yuccas of the source of error if adopted exists.
Scientific Sense
"cepheids" Discussed on Scientific Sense
"One hundred to be reasonable for color cones that happened in the nineteen seventies most of the values that people were measuring were falling in that range of fifty two hundred and we had that situation for a few decades two or three decades and and then with the launch of the hubble space telescope so i and thirty other astronomers at what was known as the humble key project to measure distances to galaxies using the same cepheid variables that edwin hubble hubbell had originally used but advantage of being able to get above the earth's atmosphere to correct for reddening using these c- charge couple device detectors and and be able to correct for the presence of dust. That was something that My in fact. Phd thesis was to come up with a technique that allows you to do that. And so that's how we resolve. The factor of two discrepancy between fifty and one hundred was through the hubble key project and an measuring evaluate hubble constant. We got seventy two but for the first time with an accuracy of ten percent rather than this crazy factor to that. We had to live with for for several decades. And so severe. Settling down in the in the mid seventies The this you said in nineteen seventies eighties. Yeah the nineteen seventy eighty two series a number of different studies in the seventies and eighties. That were getting values between fifty and one hundred and people were know sort of accepting it there's some agents in it but but we can get better and better dimensions I should have solutions that might constrain it better and then we had bit of an issue right more recently. So the paper you say the interesting juncture Despite vast improvements in the measurement accuracy of the hubble constant most often denoted as h zero if recent tension has them that is either signity new physics or as yet unrecognised on certainties. So so you found a understandability be found different ways to measure cobbled constant and those different methods are sorta diverging instead the problem..
SpaceTime with Stuart Gary
Milky Way Warped and Twisted
"Accurate three dimensional map of Milky Way. Galaxy shows that it's warped and twisted. A report in the journal nature astronomy claims this woop spiral patent is being caused by talk of spinning of the milky way's massive in disk of stars than you observations of based on the positions of one thousand three hundred thirty nine syfy variable stars, which will use to map the milky ways real shape. They found the milky way's disk of stars becomes increasingly warped and twisted. The further away the stars are from the galactic Santa one of the study's authors. Professor Richard de grace from MacQuarie university says people usually think of spiral galaxies as being flat discs. The problem is trying to determine the rue shave avow. Galaxy is bit like standing in the middle of the woods trying to determine the exact size and shape of the hull forest. It's also the touristy difficult to determine distances from the sun to some parts of the milky ways. Gaseous disk without having a clear idea of what the disc actually looks like however of the past fifty years or so the have been some tantalizing hints that hydrogen clouds in the Milky Way could be warped from a great distance. I'll spiral galaxy look like thin disk of stars that obits roughly once every two hundred and fifty million years around the central region where hundreds of billions of stars provide all the gravitational glue native the whole the galaxy together. The Pat from dot matter that is, but it now seems this pull of gravity is far waker in the galaxies fi outta disk there. The hydrogen atoms making up most of the galaxy's gas disk no longer confined to a thin plane. Instead, they give the disk and s like a wolf to peerages coast by the huge man of toll coming from the spinning the milky way's massive in a disc of starves the Katie developing. This new three-dimensional map was recently published catalogue of young variable stars, none is classical Cepheids located in the wool Milky Way. Disc. Data on the east is was provided by Nashes wise wide field. Infrared survey explorer spacecraft the authors rebel, use a thousand three hundred thirty nine of these had variables to help them develop. They Matt and this allowed them that attempt that twisted appearance of the galaxies fire out a ragions classical Cepheids some four to twenty times as massive as the sun and up to one hundred thousand times as bright syfy at variables pulse. I that. He's expanding contract at set rates based on their intrinsic luminosity. And so that can be used the standard candles to measure cosmic distances because strana is no hang trinity luminous syfy variable star is because it's Paul sation. Right. They can determine how far away it must be. It's exactly the same. As looking at a row of straight lights down the road. You know, the vocal at the same brightness for the ones further down the road will appear dim it than the ones near it to you. This allows very accurate distances to determined for the stars with an era. Of only three to five percent. Then you research provides a crucial updated map for studies of the Milky Way, still emotions the origins of the milky way's disc. The grace reminds us that most of the matter in the milky ways dot matter, which is an intrinsic part of a universe. But the grace also points out that not only decide to not have any idea. What dot matter is not even sure exactly where it is. The new research the roszak of the Milky Way could help scientists better determine how dot matter is distributed around the Milky Way galaxy built those role surprised to find that they three dimensional collection of one thousand three hundred thirty nine syfy variable stars and the milky gas disk shared the stars tended to follow each other closely. The grace is that a scullery off his new insights into the formation of the Milky Way. He says perhaps more importantly, you found that in the milky way's outer regions the s like still a disk is warped in a progressively more. Twisted spiral Patton. Astronomers have observed dozens of other galaxies which have shown similar, Pat. Tens degrade says that means the milky way's twists rare. But not unique what we found is that towards the outer regions of anarchy by galaxy galaxy starts to DVI Toma flat bag shack without that was known for longtime in its distribution of gasoline by gossiping hydrogen atoms of which we knew for the last five decades or so in the region. The hydrogen gas would deviate from the plain become higher on bumps on one end and lower on the other end. Now, our study under the results have found fun for the first time that the young stars in the QA Trist by so-called seat variable stars, which are quite massive there for quite young followed that same kind of warped distribution where there is a clear deviation from does flatbed geic shed. But that's not everything also found is that the main direction of this war is not a straight line. But it starts to Marlins chase a spiral structure Espy go further for that. In the sense that this war becomes twisted at greater and greater radio as this. Anything to do at all with the total on stars within the galaxy coast by the galaxy's rotation. Yeah. So our interpretation of this result is not the massive disc of star king up. Most of the milk is rotating around the center of the galaxy. Every tune is sixty two three hundred million years, and it's dragging behind it the outer layers, which are less strongly gravitationally bound to the milky right because I've much further is and so that rotation the warped. Our two disc is slightly lagging behind is there any connection between this this warped structure in the thick and thin disks of the Milky Way is the correlation. And that's a good question. But we haven't actually looked up. Now having said that the dole cough the stars in. By are distributed into thin disc. That's ready to device majority of stars the thick disk is puffed up somewhat and it tends to extend to greater radio. But at much lower numbers of stars than the thinness. The the works distribution of stars would deviate from this thing this in the into the realm of the thickness. So there might be some dynamically. Action. But I would say about the warp itself is originates from the thin. That's probably must less associated with Findus. I don't think this has to do with the spiral structure of the milky QA such because it's quite well known by now death, the the longevity of the spiral arms is due to something called density Reich Swiss stars move around the center of the Milky Way, and they get attracted by the higher density of potato in despite alarm today that move faster towards spiral. I've spent more time there because of gravity and they move out slowly between his firearms that don't spend much time. That's that's the density by feary. I think there's a difficult. That's that's a completely different dynamical process in in this particular case, we believe that we really sees graft national torquing dragging behind of material by the inner massive disc. What do you need to do next for your research? Well, there's a couple of things that we can do first of all we looked at about thirteen hundred or so of the variables that's sizable sample. But it's know. You can always be improved one of the problems with our sample is that all of these stars were located on the near side of the nookie right centers on our side of the center. It would be great if he could get similar quality data on the other side of the QA center. So that we could see whether or not the features out. We have found are symmetrical, and that is more than just an academic exercise. The idea here is if the warts distribution of the seats in the twisting, this symmetrical either side of the Milky Way center, then we truly have a process here that works across the galaxy. Comex have suggested that what we we've seen might have been caused by the info of dwarf galaxy towards the region stuff, I'm Yukio. And if that's stick as you would only expect your side. So that's one thing that we would like to explore another thing, of course, is probably not very well. The European Space Agency is currently operating its guy satellite, which is meant to determine positions and distances to about a billion stars nuclei galaxy the first data released has has come out in the second releases Jew soon, but the full date. Percents will not be released for another three to five years by that time accurate three d map of nuclear galaxy. At hopefully, result will serve as a benchmark to hold those guy results against and I finally the other quite exciting prospects here is that by concentrating distribution of stars in our Milky Way. More a better more carefully before we may have a fighting chance of determining all the doc metro is located and that's still a big open question. That's professor Richard grace from Corean versity in Sydney,
SpaceTime with Stuart Gary
Milky Way Warped and Twisted
"Accurate three dimensional map of Milky Way. Galaxy shows that it's warped and twisted. A report in the journal nature astronomy claims this woop spiral patent is being caused by talk of spinning of the milky way's massive in disk of stars than you observations of based on the positions of one thousand three hundred thirty nine syfy variable stars, which will use to map the milky ways real shape. They found the milky way's disk of stars becomes increasingly warped and twisted. The further away the stars are from the galactic Santa one of the study's authors. Professor Richard de grace from MacQuarie university says people usually think of spiral galaxies as being flat discs. The problem is trying to determine the rue shave avow. Galaxy is bit like standing in the middle of the woods trying to determine the exact size and shape of the hull forest. It's also the touristy difficult to determine distances from the sun to some parts of the milky ways. Gaseous disk without having a clear idea of what the disc actually looks like however of the past fifty years or so the have been some tantalizing hints that hydrogen clouds in the Milky Way could be warped from a great distance. I'll spiral galaxy look like thin disk of stars that obits roughly once every two hundred and fifty million years around the central region where hundreds of billions of stars provide all the gravitational glue native the whole the galaxy together. The Pat from dot matter that is, but it now seems this pull of gravity is far waker in the galaxies fi outta disk there. The hydrogen atoms making up most of the galaxy's gas disk no longer confined to a thin plane. Instead, they give the disk and s like a wolf to peerages coast by the huge man of toll coming from the spinning the milky way's massive in a disc of starves the Katie developing. This new three-dimensional map was recently published catalogue of young variable stars, none is classical Cepheids located in the wool Milky Way. Disc. Data on the east is was provided by Nashes wise wide field. Infrared survey explorer spacecraft the authors rebel, use a thousand three hundred thirty nine of these had variables to help them develop. They Matt and this allowed them that attempt that twisted appearance of the galaxies fire out a ragions classical Cepheids some four to twenty times as massive as the sun and up to one hundred thousand times as bright syfy at variables pulse. I that. He's expanding contract at set rates based on their intrinsic luminosity. And so that can be used the standard candles to measure cosmic distances because strana is no hang trinity luminous syfy variable star is because it's Paul sation. Right. They can determine how far away it must be. It's exactly the same. As looking at a row of straight lights down the road. You know, the vocal at the same brightness for the ones further down the road will appear dim it than the ones near it to you. This allows very accurate distances to determined for the stars with an era. Of only three to five percent. Then you research provides a crucial updated map for studies of the Milky Way, still emotions the origins of the milky way's disc. The grace reminds us that most of the matter in the milky ways dot matter, which is an intrinsic part of a universe. But the grace also points out that not only decide to not have any idea. What dot matter is not even sure exactly where it is. The new research the roszak of the Milky Way could help scientists better determine how dot matter is distributed around the Milky Way galaxy built those role surprised to find that they three dimensional collection of one thousand three hundred thirty nine syfy variable stars and the milky gas disk shared the stars tended to follow each other closely. The grace is that a scullery off his new insights into the formation of the Milky Way. He says perhaps more importantly, you found that in the milky way's outer regions the s like still a disk is warped in a progressively more. Twisted spiral Patton. Astronomers have observed dozens of other galaxies which have shown similar, Pat. Tens degrade says that means the milky way's twists rare. But not unique what we found is that towards the outer regions of anarchy by galaxy galaxy starts to DVI Toma flat bag shack without that was known for longtime in its distribution of gasoline by gossiping hydrogen atoms of which we knew for the last five decades or so in the region. The hydrogen gas would deviate from the plain become higher on bumps on one end and lower on the other end. Now, our study under the results have found fun for the first time that the young stars in the QA Trist by so-called seat variable stars, which are quite massive there for quite young followed that same kind of warped distribution where there is a clear deviation from does flatbed geic shed. But that's not everything also found is that the main direction of this war is not a straight line. But it starts to Marlins chase a spiral structure Espy go further for that. In the sense that this war becomes twisted at greater and greater radio as this. Anything to do at all with the total on stars within the galaxy coast by the galaxy's rotation. Yeah. So our interpretation of this result is not the massive disc of star king up. Most of the milk is rotating around the center of the galaxy. Every tune is sixty two three hundred million years, and it's dragging behind it the outer layers, which are less strongly gravitationally bound to the milky right because I've much further is and so that rotation the warped. Our two disc is slightly lagging behind is there any connection between this this warped structure in the thick and thin disks of the Milky Way is the correlation. And that's a good question. But we haven't actually looked up. Now having said that the dole cough the stars in. By are distributed into thin disc. That's ready to device majority of stars the thick disk is puffed up somewhat and it tends to extend to greater radio. But at much lower numbers of stars than the thinness. The the works distribution of stars would deviate from this thing this in the into the realm of the thickness. So there might be some dynamically. Action. But I would say about the warp itself is originates from the thin. That's probably must less associated with Findus. I don't think this has to do with the spiral structure of the milky QA such because it's quite well known by now death, the the longevity of the spiral arms is due to something called density Reich Swiss stars move around the center of the Milky Way, and they get attracted by the higher density of potato in despite alarm today that move faster towards spiral. I've spent more time there because of gravity and they move out slowly between his firearms that don't spend much time. That's that's the density by feary. I think there's a difficult. That's that's a completely different dynamical process in in this particular case, we believe that we really sees graft national torquing dragging behind of material by the inner massive disc. What do you need to do next for your research? Well, there's a couple of things that we can do first of all we looked at about thirteen hundred or so of the variables that's sizable sample. But it's know. You can always be improved one of the problems with our sample is that all of these stars were located on the near side of the nookie right centers on our side of the center. It would be great if he could get similar quality data on the other side of the QA center. So that we could see whether or not the features out. We have found are symmetrical, and that is more than just an academic exercise. The idea here is if the warts distribution of the seats in the twisting, this symmetrical either side of the Milky Way center, then we truly have a process here that works across the galaxy. Comex have suggested that what we we've seen might have been caused by the info of dwarf galaxy towards the region stuff, I'm Yukio. And if that's stick as you would only expect your side. So that's one thing that we would like to explore another thing, of course, is probably not very well. The European Space Agency is currently operating its guy satellite, which is meant to determine positions and distances to about a billion stars nuclei galaxy the first data released has has come out in the second releases Jew soon, but the full date. Percents will not be released for another three to five years by that time accurate three d map of nuclear galaxy. At hopefully, result will serve as a benchmark to hold those guy results against and I finally the other quite exciting prospects here is that by concentrating distribution of stars in our Milky Way. More a better more carefully before we may have a fighting chance of determining all the doc metro is located and that's still a big open question. That's professor Richard grace from Corean versity in Sydney,
SpaceTime with Stuart Gary
Milky Way Warped and Twisted
"Accurate three dimensional map of Milky Way. Galaxy shows that it's warped and twisted. A report in the journal nature astronomy claims this woop spiral patent is being caused by talk of spinning of the milky way's massive in disk of stars than you observations of based on the positions of one thousand three hundred thirty nine syfy variable stars, which will use to map the milky ways real shape. They found the milky way's disk of stars becomes increasingly warped and twisted. The further away the stars are from the galactic Santa one of the study's authors. Professor Richard de grace from MacQuarie university says people usually think of spiral galaxies as being flat discs. The problem is trying to determine the rue shave avow. Galaxy is bit like standing in the middle of the woods trying to determine the exact size and shape of the hull forest. It's also the touristy difficult to determine distances from the sun to some parts of the milky ways. Gaseous disk without having a clear idea of what the disc actually looks like however of the past fifty years or so the have been some tantalizing hints that hydrogen clouds in the Milky Way could be warped from a great distance. I'll spiral galaxy look like thin disk of stars that obits roughly once every two hundred and fifty million years around the central region where hundreds of billions of stars provide all the gravitational glue native the whole the galaxy together. The Pat from dot matter that is, but it now seems this pull of gravity is far waker in the galaxies fi outta disk there. The hydrogen atoms making up most of the galaxy's gas disk no longer confined to a thin plane. Instead, they give the disk and s like a wolf to peerages coast by the huge man of toll coming from the spinning the milky way's massive in a disc of starves the Katie developing. This new three-dimensional map was recently published catalogue of young variable stars, none is classical Cepheids located in the wool Milky Way. Disc. Data on the east is was provided by Nashes wise wide field. Infrared survey explorer spacecraft the authors rebel, use a thousand three hundred thirty nine of these had variables to help them develop. They Matt and this allowed them that attempt that twisted appearance of the galaxies fire out a ragions classical Cepheids some four to twenty times as massive as the sun and up to one hundred thousand times as bright syfy at variables pulse. I that. He's expanding contract at set rates based on their intrinsic luminosity. And so that can be used the standard candles to measure cosmic distances because strana is no hang trinity luminous syfy variable star is because it's Paul sation. Right. They can determine how far away it must be. It's exactly the same. As looking at a row of straight lights down the road. You know, the vocal at the same brightness for the ones further down the road will appear dim it than the ones near it to you. This allows very accurate distances to determined for the stars with an era. Of only three to five percent. Then you research provides a crucial updated map for studies of the Milky Way, still emotions the origins of the milky way's disc. The grace reminds us that most of the matter in the milky ways dot matter, which is an intrinsic part of a universe. But the grace also points out that not only decide to not have any idea. What dot matter is not even sure exactly where it is. The new research the roszak of the Milky Way could help scientists better determine how dot matter is distributed around the Milky Way galaxy built those role surprised to find that they three dimensional collection of one thousand three hundred thirty nine syfy variable stars and the milky gas disk shared the stars tended to follow each other closely. The grace is that a scullery off his new insights into the formation of the Milky Way. He says perhaps more importantly, you found that in the milky way's outer regions the s like still a disk is warped in a progressively more. Twisted spiral Patton. Astronomers have observed dozens of other galaxies which have shown similar, Pat. Tens degrade says that means the milky way's twists rare. But not unique what we found is that towards the outer regions of anarchy by galaxy galaxy starts to DVI Toma flat bag shack without that was known for longtime in its distribution of gasoline by gossiping hydrogen atoms of which we knew for the last five decades or so in the region. The hydrogen gas would deviate from the plain become higher on bumps on one end and lower on the other end. Now, our study under the results have found fun for the first time that the young stars in the QA Trist by so-called seat variable stars, which are quite massive there for quite young followed that same kind of warped distribution where there is a clear deviation from does flatbed geic shed. But that's not everything also found is that the main direction of this war is not a straight line. But it starts to Marlins chase a spiral structure Espy go further for that. In the sense that this war becomes twisted at greater and greater radio as this. Anything to do at all with the total on stars within the galaxy coast by the galaxy's rotation. Yeah. So our interpretation of this result is not the massive disc of star king up. Most of the milk is rotating around the center of the galaxy. Every tune is sixty two three hundred million years, and it's dragging behind it the outer layers, which are less strongly gravitationally bound to the milky right because I've much further is and so that rotation the warped. Our two disc is slightly lagging behind is there any connection between this this warped structure in the thick and thin disks of the Milky Way is the correlation. And that's a good question. But we haven't actually looked up. Now having said that the dole cough the stars in. By are distributed into thin disc. That's ready to device majority of stars the thick disk is puffed up somewhat and it tends to extend to greater radio. But at much lower numbers of stars than the thinness. The the works distribution of stars would deviate from this thing this in the into the realm of the thickness. So there might be some dynamically. Action. But I would say about the warp itself is originates from the thin. That's probably must less associated with Findus. I don't think this has to do with the spiral structure of the milky QA such because it's quite well known by now death, the the longevity of the spiral arms is due to something called density Reich Swiss stars move around the center of the Milky Way, and they get attracted by the higher density of potato in despite alarm today that move faster towards spiral. I've spent more time there because of gravity and they move out slowly between his firearms that don't spend much time. That's that's the density by feary. I think there's a difficult. That's that's a completely different dynamical process in in this particular case, we believe that we really sees graft national torquing dragging behind of material by the inner massive disc. What do you need to do next for your research? Well, there's a couple of things that we can do first of all we looked at about thirteen hundred or so of the variables that's sizable sample. But it's know. You can always be improved one of the problems with our sample is that all of these stars were located on the near side of the nookie right centers on our side of the center. It would be great if he could get similar quality data on the other side of the QA center. So that we could see whether or not the features out. We have found are symmetrical, and that is more than just an academic exercise. The idea here is if the warts distribution of the seats in the twisting, this symmetrical either side of the Milky Way center, then we truly have a process here that works across the galaxy. Comex have suggested that what we we've seen might have been caused by the info of dwarf galaxy towards the region stuff, I'm Yukio. And if that's stick as you would only expect your side. So that's one thing that we would like to explore another thing, of course, is probably not very well. The European Space Agency is currently operating its guy satellite, which is meant to determine positions and distances to about a billion stars nuclei galaxy the first data released has has come out in the second releases Jew soon, but the full date. Percents will not be released for another three to five years by that time accurate three d map of nuclear galaxy. At hopefully, result will serve as a benchmark to hold those guy results against and I finally the other quite exciting prospects here is that by concentrating distribution of stars in our Milky Way. More a better more carefully before we may have a fighting chance of determining all the doc metro is located and that's still a big open question. That's professor Richard grace from Corean versity in Sydney,