Let's Find Out - Supernovae and Variable Stars: Astronomy in 1836 vs 2020 | ASMR soft spoken

Episode Date: September 26, 2020

Shop Manta Sleep's awesome masks here: https://bit.ly/3hNihMZ (10% off if you use LETSFINDOUT at checkout thru 12/15/2020) In 1836 astronomy was still a budding science. The Andromeda galaxy was still just a curiosity; a hazy nebula yet to be explored. Supernovae were still deep mysteries. And the thought that our universe could be more than 100,000 light-years across was unheard of. Let's find out how far our knowledge of space (supernovae and variable stars, in particular tonight), has come in 200 years. "...it is a matter of having the courage for an attack upon one's own convictions" -Nietzsche ▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬ #ASMR #space #astronomy

Cracking open this 1836. Geography of the heavens by Elijah H. Burritt, accompanied by a celestial Atlas, which we don't have in person, but I was able to actually track down through the Internet Archive, a super high-deaf version of the accompanying celestial Atlas. And tonight we're going to be looking at this book through the lens of modern astronomy. We're going to look and compare the 200, nearly 200-year-old for those nitpickers out there. 200-year-old astronomy. The information, what they knew, with modern understandings to the extent that we can say we understand the physics, astrophysics, of what's going on out there. So our focus tonight is going to be chapter 13 in this book.

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the channel. Let's put that aside, get back to the topic at hand. We're going to learn about stars and what Elijah Burritt coalesced from the knowledge of early 19th century 1800s astronomy. Always smiling because I always have the intention of making things into a series and returning to them, but many things I don't come back to. But if we do, tonight will be the first in a series exploring the you know comparing the the knowledge gap across two centuries of time tonight's video is going to focus on chapter 13 which is primarily revolving around stars but in particular from the point of view of this book it's going to be stars binary stars star clusters

and lastly the fourth section. It's going to be nebulae. And keep in mind, this was probably a hundred years before the radical realization, primarily from the work of Edwin Hubble, the great astronomer after whom the telescope is named, the discovery of galaxies was a hundred years away in this book. So what they call nebulae is a nebulae, is a nebulae class classification of celestial objects into which galaxies are but one subcategories. So let's open this up to Dad from 1970. Thinking about how many hands this book has probably been through. 13. I've done a little background research, so I got the laptop right there, ready to go. And what we're going to do is take it almost point.

point by point we're gonna we're gonna find section by section what he points out a little you know details and facts and things he focuses on so that we can kind of jump from there to the current era so here our index unlike modern table of contents they kind of just throw the index at the beginning instead of a table of contents going in consecutive page order. So we got to go alphabetically. In chapter 13 is on stars. So we're going to be starting on page 137. Yeah, actually, it's like two books in one almost.

I forgot about that. It's been a while since we recorded our last part. It's interesting that because the bulk of I guess part one is on the constellations You know find them how do you know spot them there there are mythological backgrounds And then at the very end of part one chapter 13 he broke them up into the 12 zodiac signs The first you know chapter about observational astronomy more concrete classifications of objects we'd see more similarly in a modern-day astronomy book he starts at the end of part one you would think you would

kind of section that into book two but anyways on page 137 here we got chapter 13 he breaks into four sections we have one variable stars double stars clusters clusters on top right there lastly section four nebulae chapter 13 here starts with section one variable stars the periodical variations of brilliancy to which some of the fixed stars are reckoned among the most remarkable of their phenomena several stars formerly formally distinguished by their splendor have entirely disappeared. Others now conspicuous, which do not seem to have been visible to the ancient observers, though some have disappeared, some seem to have arisen out of dark patches, black in the sky, some which alternately, alternately appear and disappear,

or at least of which the light undergoes periodic changes. Some seem to be, become gradually more obscure as Delta in the Great Bear, and others like Beta in the whale seem to be increasing in great splendor. Great splendor, great splendor. And after a gradual diminution of their light, again become extinct. beta and let's see delta in the great bear and beta in the whale now I want to try not to make this into just about the constellations but I do want to put everything we're reading in the next few pages into context and again channel I named it let's find out because I like to challenge myself and learn new things and as interested in astronomy as I've always been, I've actually never been interested in learning about the constellations. I guess I didn't like it because of its technological but more importantly astrological

undertones because I didn't like the superstitious undertones that come with astrology and knowing your zodiac signs and, you know. As Carl Sagan famously refuted, disputed, the superficial labeling of personality traits based on the particular alignments of the planets and the stars during which month and year a person was born. I'm still not convinced really at all by the influence on a particular person's purpose. personality that that might have. But after reading in particular Carl Jung's book, Ion, I am much more open to the projection that the ancients had, especially pre-scientific ancients, the projections of psychology, psychological archetypes, and unconscious ideas and motivations that the ancients did and, you know, significantly projected onto star patterns in the cosmos, and how those seem to have influenced history, at least to some extent.

But I guess that's for another episode about how ion being the revolution of the zodiacal signs and how they do align. and the wobble, the procession of the equinoxes completes a full rotation every 24,000 years. That would mean that every 2,000 years, and it's been roughly 2,000 years since the birth of Christ, there is a new ion or ion that is in a particular part of the sky at a particular time.

And so that changes every 2,000 years due to the wobble of the earth on its axis. And right at the time of Christ, just this is a little side note, the age was the, which was it? So he, we recently are about to or recently did, because it's, you know, it's a 2000-year phenomenon.

You can't say there's an exact date. The fine transition period is a little broader than just one day. It's maybe a couple centuries, you know. But Christ, we're in the age of Aquarius. Christ represented the age of Pisces, the fish. That's why the Christian symbol is the fish. And so often it's both the cross, but it's also the fish. He was the known as the fisher of men, for instance. He was able to, uh, and there's many allegories, you know, parts in the Bible where Jesus was able to make do certain miracles that involved fish. And then, I believe before him, it was the age of the, was it the goat? Let's see. Researches into the phenomenology

of the self. He tried to make a case for Christ as being the fulfillment of an expected or prophetic tradition and I guess without getting too deep into it it's just interesting as a guy who studied psychology so thoroughly and wanted to extract the most value out of religion the traditions of alchemy, astrology, mysticism and Gnosticism. He recognized that before science, we didn't have any methods for reaching an objective truth

the way science currently does. So he was looking through the old texts. Realized that, as we can see here, here the astronomical symbols. It goes Gemini, Taurus, Ares, and then Pisces. From 2000 BC to the year zero when Christ was born, that was supposedly the age of the ram. These 2,000 year cycles transition around, roughly around the year zero, when Christ bore in the new. He represented the dying ram in the birth of the fish, age of Pisces, which now has just concluded or is in the process of concluding. And then as you see here, let's see, Pisces turns into Aquarius down here.

So Carl Young was interested in ideas can propagate through cultures and what these ideas mean for what goals a culture has. So the Jewish culture and the tradition that Jesus was a revolutionary prophet in had its series of prophecies that were waiting to be fulfilled. So you can say that centuries, centuries, even millennia of thought and effort, cultural development, and religious speculations were put into what Christ ultimately became. And so Carl Jung's point was at the assumption that certain things are going to happen in a weird way makes some things happen sometimes. If people want something bad enough, sometimes they get it.

And sometimes when they're looking for patterns hard enough, they see it even if objectively there might not have been that pattern there to the person who wasn't looking for it so anyways the reason i brought that all up was because young wrote an entire portion of this book if not kind of the whole book itself really of eye on in his later years um trying to understand all the where the origin why would this symbol that is part of astrology how did that attach itself to a figure on earth and how did it come to be identified with a human being you know who claim to be a great moral prophet bringing in new values to the human species at least to a section in the in the western world.

How did he come to identify with the fish? Jesus was born as the first fish of the Pisces era. He was doomed to die as the last ram or lamb of the declining Ares era. Yeah, here, a direct astrological aspect of Christ's birth is given us in Matthew 2, verse one, the magi from the east were stargazers who beholding an extraordinary constellation inferred an equally extraordinary birth. That's all very interesting. The influence that the stories and mythological characters were projected onto the stars and you know for human lifespan's eternal stars and stars and

their eternal positions. Something we can latch on to something that is unchanging throughout many human generations. So it's, it acts as a, you know, a stone, a uneroding stone in which we can inscribe our human stories and our narratives and our evolved and transmitted wisdom. And again, pre, you know, not 1900 everywhere you went the star as long as it wasn't cloudy even with a full moon I'm sure was absolutely lit up with sharp the hundreds of thousands of sharp points of light beaming in the night sky which you can only imagine how how much that must have infused the human imagination with wonder and awe and speculation and a desire to know more about the world

and create, create stories, tell stories, share ancestral wisdom, the longest stories, like the Iliad and the Odyssey and Gilgamesh were only transmitted orally. and in order for that game of telephone to not distort the fundamental truths that we sought to transmit that were so hard won over generations that the values and wisdom that we couldn't afford to lose as a culture as a civilization in order for those to not get lost and distorted it was very important to have a widely agreed upon series of myths and stories that were imprinted onto an objectively existing external phenomena like the stars you know even mountains can erupt and erode and have landslides rivers can change their course meander in different directions even

within a generation or two. Climates can change, but the stars, in human terms, the stars are eternal and unchanging. This thing I said here was connection between, you know, myth and astronomy and stars in the cosmos is significant because astrology was astronomy back in the day. The two were not yet separated and distinct. They were the same. think. So if you were to study the stars, you necessarily had to understand the stories that are linked to those stars. Knowledge was stored, so to speak, in the stars back then. And therefore, all that equal the wisdom in antiquity, the wisdom of antiquity. So a narrative as potent as Christ's at the dawn of a new ion initiated a chain reaction of belief, spirituality, in hope.

So the idea that someone was a prophet is very much influenced by expectations, which are in turn influenced by the stories cultures tell themselves. So in other words, we already kind of have, we're primed as a culture, especially back. than pre-scientific mystical and supernatural phenomena happening all around us very wanting to believe very ready to believe in something that shows qualities of a divinity so I was very much interested in in Young's interest in why Christianity stuck and became so popular in the way that it did. So our first constellations we're going to be looking at our Delta, the Great Bear.

We want to look at Delta in the Great Bear, and the general mechanism for naming stars is to look at the most prominent stars in those constellations and name them the letters of the Greek alphabet. So delta, a variable star that seems to become gradually more obscure whereas beta in the whale is increasing in its brilliancy. So variable stars are in modern astronomical terms, what we understand them as is a star whose brightness as seen from Earth, meaning its apparent magnitude,

because it's as opposed to its intrinsic magnitude, which would be its objective brightness, because we are representing one vantage point on Earth from the cosmos. And the star's brightness might change if we are, depending on our distance, depending on any nebula, you know, gaseous clouds, or our atmosphere blocking the light. So as it appears from Earth, a variable star, as a star whose brightness fluctuates, as seen from Earth, this variation can be caused by a change in emitted light

or by something particularly partly, something partly blocking the light. So variable star, are classified, again using the intrinsic extrinsic distinction I just made, as intrinsic variables whose luminosity actually changes, for example, because the star periodically swells and shrinks, extrinsic variables on the other hand are stars whose apparent changes in brightness are due to changes in the amount of light that is able to reach Earth. For example a star has an orbiting

companion that might sometimes eclipse it from at least from our perspective. So if we happen to be exactly on the plane of the orbital path of a binary system or a star with a really large planet, um Those two objects are going to seem to, you know, eclipse each other. So what, uh, what's that called? Occulting, occulting, I think. And possibly most stars have at least some variation in luminosity. The energy output of our sun, for instance, varies by about a tenth of a percent,

over an 11-year solar cycle. So here we see this picture of, the Big Dipper right here and Delta and so in this book the way they the the nomenclature and that was the word I was looking for earlier the nomenclature that Burrett gives in his book here is the Greek letter and then the name in which that Greek letter of the the name of the constellation in which that star exists nowadays we have oftentimes either the you know technical designation of the star which is like an

acronym with some long list of numbers after it or it's a individually named star so Delta in the Great Bear in the Great Bear is yeah I guess I'll just click the great bear the Big Dipper is the tail of the Great Bear so let's open the main stars in the tail and then the four main stars making up the uh zoom in even further making up the body uh or at least the hind quarters of the bear in the bear uh is called ursa major ursa meaning bear major meaning big but in the star we're looking for delta in the big bear is called, it's right here, called Megres, Megres. So this star has an excess emission of infrared radiation,

indicating the presence of circumstellar matter. So this forms a debris disk around an orbital radius of about 16 astronomical units, or distances from our distance from the Sun, about roughly 90 million miles. So 16 times the Earth's distance from the Sun, astronomical units or a U, is about how far out. Megres is orbital, circumstellar orbital disk of debris is orbiting. So Meghrez actually has two faint companions, a tenth magnitude star, and an 11th magnitude star.

So both an angular separation of two arc minutes from the primary. And by the way, Megres, coming from the Arabic, Al-Magreys, the base, meaning the base of the bear's tail, is an indication just this one of many stars that we're actually going to be seeing today that have its name derived from an Islamic word. So just like there's many stars of Latin origin in terms of their name, there is actually in the Islamic golden age of our Middle Ages in Europe. There were many great astronomers and thinkers

and early proto-scientists whose knowledge was in one way or another transmitted to the European civilization in the late Middle Ages. So, yeah, so now we know Megres actually has two faint companions and they just orbit so slow

that it just happened to coincide. at the time of, you know, the last century or so of observations, according to Burrett here, that Meghrez or Delta in the Great Bear was becoming gradually more obscure. So perhaps both the binaries were, and apparently Megres is about 63% more massive than the sun, giving it a radius of about 1.4 times the sun as well. I can't find how long it takes them to orbit it, but from what I found a lot of the orbits are actually kind of, I guess you can imagine, whether it's the companion stars

or the circumstellar disk that's creating the obscurity, anything out that far given that it's about was that roughly the same orbit as Jupiter or no Saturn I guess let's see Saturn orbital distance is a u so uranus is about 19.8 so almost 20 a u from the Sun in Uranus's orbit 84 earth years So, you know, you're looking at a, anywhere from maybe 60 to 150, something like that, period, orbiting this Meghrez star, creating its variability, so to speak. So beta now, this was the one that Burritt says was, seemed to be increasing in brightness. So Megres was gradually becoming more obscure. beta in the whale in the whale is the constellation cete or cete or c e i so beta so those would be

beta seti difta that's another name is the brightest star in the constellation so beta is right here it's at the base of that triangle right there of constellation cedus i guess Although designate beta, it's actually brighter than the alpha star in the constellation. Alpha being the size of the star designates its magnitude. Oh, and that's the other thing, the two faint companions of Megarez. It said they were 10th and 11th magnitude stars. That is, in general, on a scale that means the larger the numbers, the number is the... more faint, smaller the number.

Going all the way into the negatives even means a more luminous, more bright star. So, for instance, Venus being Venus and Jupiter, being the more the brightest, when you say normal objects in the sky, regular objects in the sky, meaning something like that regularly occurs as opposed to a supernova one-off events those actually have negative magnitude meaning brightness so so beta in the whale so our difta or beta seti it displays flaring activity that results in random outbursts that increase the luminosity of the star over intervals lasting several days. So it's interesting that he Burritt in the book picked these two stars because they're

great examples of their respective extrinsic and intrinsic variability. Beta in the whale here being an intrinsically variable star because it is a Its own properties are what create the variability in its luminosity. Whereas our Megres or Delta in the Great Bear was only varying from our perspective because there was a debris blocking its light from reaching us. Difta has a our beta in the whale here, beta. Random outbursts that last several days. This is a much longer duration than that comparable to our own solar flares that we see on our star,

which only lasts typically about a few hours, or at least durations measured in hours rather than days. And actually, this was another kind of difficult one to track down, because the whale constellation Cetus, There is a star called Mira. You'll notice here, it's the only star with a proper name, with its own name, that's not a Greek letter. And I almost mistook that for beta, you know,

Burrits, beta in the whale here for Mira, also called Omicron SETI. Its Greek letter is Omicron. Because in 1596, in fact it's on the front page, If you look up the Wikipedia page for Variable Star, Omicron SETI, or Mira, which I think is kind of a, would be kind of a cool name. I know it means look in Spanish, but it's on the top, it's kind of the, it's kind of the, it's a great, it's like the primary example of a variable star. because in 1596 Mira Latin which is oh Latin for astonishing

had been described as a Nova but would later become the first non-supernova variable star discovered when Johannes Alwarda noticed it pulsating taking 11 months in 11 month cycle Mira combined with supernova of 1572 and 1604, a very, yeah, that was the time around Galileo, in Taekobrahi and I think Copernicus,

that was the late stages of Copernicus's life, I guess. That Gobrahe was, he died in 1601, interesting, so he didn't get to see the, the 1604 supernova. Very interesting. in his relation with Kepler so yeah that was around the time of Kepler Kepler lived till 1630 and then Copernicus Pernicus lived oh Copernicus was a hundred years before Galileo Teco and Kepler Copernicus died in 1543 so that's why he's always the more important out of all those because he was so ahead of his time really um so he died well before 1572

and 1604 two landmark astronomical observations that were um pivotal in in breaking the mold set in stone by Aristotle, you know, almost almost 2,000 years before that, well over 2,000 years ago for us. Aristotle essentially convinced everybody because he was such a formidable intellect who was an expert over so many areas of, you know, inquiry. Around 300 BC, Aristotle, everybody that the cosmos the firmament was eternal and fixed in a way that you know is unchanging over all time so the heavens were the realm of the you know a realm of an entirely different nature than the earth the earth was dynamic and you know we have all the again like I said weather climate atmosphere are changing

geological features, rivers oceans, everything's fluctuating. And Aristotle was firm that the heavens were firm. But the supernova actually were led to a paradigm shift. The observation of Mira combined with the supernova's 1572 and 1604 proved that the starry sky was not eternally invariable, as Aristotle had taught Europe. to believe. In fact, for a thousand years, it's interesting that Aristotle was known as the philosopher. So there was no one greater than Aristotle's opinion, which he turned out to be wrong in quite a few interesting ways. I think he, one of the more egregious examples of his,

you know, what's the word? His carelessness, I guess, in making claiming you know knowledge on something was that women had a different amount of teeth than men so maybe his subject was just an unfortunate anomaly that he just used as the the type for women's dentistry free you know 1200 so yeah in this way Mira I just wanted to bring it up because it's the textbook example of a variable star and it's one of the first if not the first variable star at first mistaken as a supernova or a nova but once it's variation because novas quickly brighten over just a couple days or weeks supernovas they they reach their their peak and then gradually diminish obviously to never return because that's the nature.

They're an exploding star, essentially. So the remnant might be a white dwarf, but it might be, you know, faintly, faintly visible if it's close by. But unlike the variable star mirror here, supernovae don't ever increase in return back to a high level of luminosity. So this mirror directly contributed to the astronomical revolution of the 16th and early 17th centuries. So while some stars seem to increase, some stars seem to diminish in brightness, like Delta and Beta there, according to him,

some stars great splendor, and after a gradual diminution of their light, again become extinct. The most remarkable instance of this kind is that of the star which appeared in 1572 in the time of Tycho Brahe. It's suddenly shone forth and this is a very famous supernova. One of only two that have ever actually, as far as we know, been observed in our own galaxy, the Milky Way.

There have been plenty others, or, you know, at least, I say many others, I guess, that we've seen in other galaxies since we've understood, you know, just in the past hundred years, I guess. There's a famous one seen in 1987, for instance. but they've all been outside our galaxy. So that's, um, so this supernova S.N. 1572, which, uh, was known as Tycho's supernova, suddenly shone forth in the constellation of Cassiopia. Cassiopeia, with a splendor exceeding that of all stars

of, uh, of the first magnitude, even Jupiter. and Venus, the brightest regular objects, other than the moon and the sun, of course, at their least distances from Earth. So even the closest that Jupiter and Venus come to Earth, it was brighter than that. It could be seen with the naked eye on the meridian in, get this, full day, that's cool. That's what this, we didn't know was a supernova at the time. They just thought maybe it was a new star or something, but, um, so its brilliancy gradually diminished from the time of its first appearance and at the end of 16 months, it entirely disappeared. It's never been seen since. And it says here, see a more particular account of this phenomena on page 40.

So I'm sure this is in the chapter on Cassiopeia, Cassiopia, Cassiopeia, I guess I like to say that better, Cassiopeia on page 40, page 40, so it's a, it's equidistant from the pole, exactly opposite of the grass, but, so I guess CAF is a star in the, man, there's so many little connections this is making right here, but calf is in the garland of the chair, almost exactly in the equinoct, Geo-collar points to Indromeda but we'll be getting to that later So in relation to this star calf There's 55 stars in Cassiopeia so it makes a very distinguishable

Constellation, but it says it's it also serves to mark a spot in the starry heavens rendered memorable as being the place of a lost star. A lost star. That's such a like a magical concept. 250 years ago, a bright star, a bright star shown 5 degrees north-north east of CAF, shown where now is a dark void. Imagine in terms of the mystical, just magical spirit,

existence that was that made up the world in the Middle Ages and prior just how massive of an impact that might have had you know speaking of instill you know constellations and the relationship between the gods and the myths that are on those constellations and now the influence the course of human events and our expectations of what's to come and the goals we set the things we fear and avoid and the things we seek and hope for and then imagine one of those one of those fundamental elements in the firmament the realm of the divine realm of the deities imagine that one day shining forth

brightly in a sort of blaze of glory only to fizzle out and never be seen from again so in terms of a like a god that would have been so such an amazing such a remarkable so impactful i bet thinking that one of the gods one of the things that has always existed when the eternal beings has just disappeared in a blaze of glory. Of course, humans being very familiar with fire for hundreds of thousands of years, for millions of years, actually. It only seems natural that we would akin that to like a funeral pyre of a deity, some kind of divine funeral for a god. On November 8th, 8th, 1572, Tygo Brahe and Cornelius Gemma saw a star in the constellation of Cassiopia,

which became all at once so brilliant that it surpassed the splendor of the brightest planets. It might even be seen, might even be seen at noon day. Gradually this great brilliancy diminished until the 15th of March, you know, five months later, when without moving from its place it became utterly extinct. Its color during this time exhibited all the phenomena of a prodigious flame. First it was of dazzling white, then a reddish yellow, and lastly of an ashy paleness, in which its light expired. It's impossible to imagine anything more tremendous than a conflagration

that could have been visible at such a distance. It was seen for 16 months. Some astronomers imagined that it would reappear again after 150 years, but it has never been discovered since. This phenomenon alarmed all the astronomers of the age who beheld it, and many of them wrote dissertations concerning it. Reverend Professor Vince, one of the most learned and pious Astronomers. of the age as this remark quote the disappearance of some stars may be the destruction of that system at the time appointed by the deity for the probation of its inhabitants in the appearance of new stars the appearance of new stars

may be for the the formation of new systems for new races of beings then called into existence to adore the works of their creator. Imagine that. Let's think so this guy was positing that perhaps there was other gods because he didn't say our creator. He says there maybe meaning that he had the notion that our god had a domain restricted to our star and he continues Burritt continues thus we may conceive the deity to have been employed from all eternity and thus he may continue to employ to be employed for endless ages forming new systems of beings to adore him and transplanting beings already formed into happier regions who will continue to rise higher and higher in their enjoyments and go on to contemplate system after system through the boundless universe in the famous, famous mathematician, astronomer Laplace, Simone Laplace, says, quote, As to those stars which suddenly shine forth with a very vivid light and then immediately disappear, it is extremely probable that the great conflagrations produced by extraordinary causes take place on their surface.

This conjecture continues, continuously, is confirmed by their change of color, which is analogous to that presented to us on earth by those brilliant bodies which are set on fire and then gradually extinguished. It's so interesting, like this is like a stepping stone into the past. This is 200 years old, talking about something itself, 200 years prior to its own. So interesting, man. So back to, well I guess we've made it to page two. But I do want to add to the supernova because it was so important. Supernova 1572. So this is called Beta Cassiopeia 15S-1572 or Tycho's supernova. This was a Type 1a supernova in the constellation Cassiopeia, one of eight supernova visible to the naked eye in historical records. In this, again, one of only two that have ever been witnessed from our own galaxy.

In the appearance of the Milky Way supernova in 1572, it belonged to one of the more important observations. in the history of astronomy because this appearance, like we said, of this new star helped to revise ancient models of the heavens, and the speed on the revolution in astronomy that began with the realization of the need to produce better astro-astometric,

astrometric star catalogs, the need for more precise astronomical observing instruments. and it challenged the Aristotelian dogma of the unchangeability in the realm of the stars. So again on the scale, this was so bright that it went into the negatives in magnitude. It was a negative 4.0 magnitude star on November 16, 1572 at its peak. Invisible into the naked eye early into 1574. gradually fading until it disappeared. And so what we know now, this is, here's a picture of it, of the supernova right here.

Let's see, what a little parsecs, or eight to 9,800 light years. A parsec is roughly, a parsec to light year is roughly the equivalent of a yard to a foot. is roughly three light years. So it's almost 10,000 light years away. Still in our galaxy. It was actually, it's been now, as we can see, observed optically, but it was actually first detected at radio wavelengths. This, I hope you guys find this interesting too, because again I love the intimate connection, I love understanding and knowing and some of the Some of it, you might be conjecture, you know, with the astrology and all that, but I just have a love of seeing the big picture. And I love it when my two loves history, one of my two interests, I guess, in astronomy come together.

Perfectly in this anecdote, this historical story from Ming Dynasty China. And this was obviously has to do with this supernova, so he was roughly around the year 1572. When the star became an issue between the chief secretary, chief consultant, to the young Wanli emperor. Wanli's father, the long-ing emperor, had died in 1572, actually, at only the young age of 35. The young, 10-year-old young Emperor Juan Lee unfortunately inherited a country still in decline due to its corruption primarily in the ruling class. But before long, but before the long. King Emperor, his father died, um, Long King had instructed the chief minister Zhang Zhuzang, the consultant Zhang Zhuzang to oversee the affairs of state and

become the dedicated advisor to his little Juan Lee and you can imagine a 10-year-old might need a loyal, dedicated, disciplined, conscientious, truthful, advisor. So beginning in 1572, Zheng became mentor and regent during the early years of the reign of Emperor Wan Li. He strongly influenced and guided him and the Chinese government was under his temporary rule through his teenage years. But from the emperor first ruling year in accordance with the cosmological tradition, he was actually warned to consider his misbehavior since the new star was interpreted as an evil omen. So right at the beginning of his reign, at 10 years old, this supernova Tycho's supernova in 1572 had exploded and erupted.

And of course, great civilizations are bound by the tradition of astrological observations and their integral effects on the narratives and the histories of their civilizations and their ancestors. So this was some sort of signal, and they took it. The Chinese took it as a evil omen. So while in temporary power, Zhang's reforms consisted of fiscal measures in order to address the persistent revenue shortage that plagued the government, an attempt to restore discipline to an increasingly corrupt bureaucracy. However, it seems the similarly strict upbringing that he also imposed on the emperor also aroused resentment, telling us that the one-le-year-old. The Emperor Little Wanli didn't heed the celestial warning of 72, 1572. And after his death, Zeng's political opponents quickly accused him in Fang Bao of several major charges.

Fang Baggus was an accomplice of Zeng's helping him rule while Emperor Wanli was maturing. and the opponents after Zeng's death accused him of corruption, embezzlement, factionalism, and as a result his family was purged, and his wealth and estate was confiscated. Confiscated on the Wanli Emperor's orders. Zeng's reputation would only be rehabilitated more than half a century later, just before the downfall of the war. the Ming Dynasty so little Wan Li was actually the last descendant of the Ming dynasty it was a great dynasty in you know late I guess maybe early Renaissance for us and

you know we're here in the Western world and it's very interesting that he disregarded and discarded he the discipline leader and mentor of his and he ended up or it ended up in his own downfall so there was a little again it's it's very very interesting the connection the correlation with how people interpret these distant events cosmological phenomena and we project and then somehow sometimes these prophecies become self-fulfilling. Seem Zang's efforts stood the test of time, while the Emperor Wanli's undisciplined behavior

made his own dynastic image. Lineage dissipate, just like the luminosity of the once bright star. So, let's see, I think. Talk about the second supernova. This called Kepler's supernova, and this was of course Tycho Bra, he died in 1601. Kepler was his independent, but yet still Kepler's, Tyco's financial tutelage, I guess.

Kepler studied under Tyco and stayed in his court and was financed by Tyco. Tyco being on top of an astronomer, also a minor royalty. and so it's kind of cool that there's a lineage there and Tycho got one named after him and 30 years later Kepler got one as well. Another instance of the same kind was observed in 1604 when a star of the first magnitude suddenly appeared in the right foot of Ophiakus. Ophiakus. It presented like the former all the phenomena phenomena of

prodigious flame being at first of dazzling white then reddish yellow and lastly of a leaden paleness in which its light expired so these instances prove that the stars are subject to great physical revelations and again it's so amazing that this guy is in the early 1800s they at the time this book was written they hadn't even discovered Neptune yet and they still in this book called Uranus Herschel after the famous astronomer Herschel who had discovered it just you know 40 or 50 years prior to the writing of this book so they don't know anything about the I think maybe 15 years before this in 1815 the first uses of spectroscopy had started, so where you look at the light coming from an object,

you break it into its rainbow spectrum essentially to its different colors, and by filtering it through a prism, you're able to, like anyone who's taken a physics lab, you're able to look, you're able to discern different spectral lines I'm trying to remember if they knew what those meant, but regardless, what they ultimately mean now is that they identify particular elements because each element, carbon, oxygen, give off and absorb light and photons at different wavelengths, depending on which element they are, I guess due to the way they interact with light, when they get energized by heat and radiation, electromagnetic radiation, they form, they get ionized. So their electrons get elevated to higher degrees, or sometimes they get stripped entirely of electrons. When they're given energy, they might absorb wavelengths of light at a certain color or wavelength.

And then when they, as they have a tendency for the electrons to fall back down to their preferred state to anthropomorphize atoms. atoms, the act of the electrons going from a larger, further away outer shell, more energized to a lower energy state shell closer to the nucleus of the atom gives off protons at a specific wavelength of light that is unique to that particular element. So based on the atomic subatomic particle, the number of protons and neutrons that interacts with light in such a way that it absorbs and emits particular specific predictable wavelengths of light so looking at a star in this book at in the early 1800s they had just started this

practice where they were filtering starlight. You can imagine how difficult that might be through filters because they're so, you know, dim. And breaking them starlight up into their specific wavelengths of their spectral lines. And being able to discern the particular, you know, densities or ratios of types of, what types of, elements the stars are made up of at least on the surface the elements that are contributing to the admitted emitted and received and detected light that the astronomers are looking at so it's cool that that gives you the context in which um the astronomers are looking at the you know the the

scientific the level of knowledge of the heavens and stars and star evolutions at the time of the writing of this book and they they're working with the bare minimum evidence yet he's able to make speculations that end up being very accurate like even though they're broad but still that the instances of supernova prove that stars are subject to great physical revolutions. We interpret that as life cycles nowadays. So in 1604, Kepler's supernova, S-N-1604, type 1a supernova as well, also occurred in the Milky Way, in the constellation Ophiakus.

This is, so within 30 years of each other roughly, and not since. It's been 420 years since our Milky Way, at least yeah, I mean I guess we could definitively say unless, you know, has seen a supernova unless some crazy series of events allowed it to be hidden from our view.

which that seems highly unlikely. So it's the most recent supernova in our galaxy to have been unquestionably observed by the naked eye. Occurring no further than 6 kiloparsecs, so multiply that by 3 and we get light years. That's roughly, they're saying roughly 18 to 20,000 light years from Earth, which is about the distance of us to... the center of the Milky Way, Sagittarius.

And prior to the adoption of the current naming system, it was named after Johannes Kepler, the German astronomer who described it in his book, his famous book, De Stella Nova. It was visible to the naked eye and brighter at its peak than any other star in the night sky had apparent, with an apparent magnitude of negative 2.5s. So not quite the negative 4.0 of Tycho's Supernova 1573.

Sorry, 72. It was visible during the day for over three weeks. And records exist beyond Europe, also in Chinese, Korean, and Arabic sources. And here we have Kepler himself actually drew from. that book, the Stellanova, the constellation depicting where in that constellation and the magnitude of the star. A grid squares down four over from. Now before we get, so that's the extent of the variable stars. And then he's going to go on to talking about binary stars, but he directs us to page 41. So that's where I'm going to go. I'm going to follow Barrett's lead.

and check out page 41. So this is just an extension of what we were reading earlier. And so right under the quote from Laplace, we have a quote from Dr. Good. Can't be bad. The late eminent Dr. Good also observes that, quote, and systems of worlds

are not only perpetually creating, but also perpetually disappearing. And it's an extraordinary fact that within the period of the last century, not less than the 13 stars in different constellations seem to have totally perished.

Totally perished, completely disappeared. In 10 years, ones seem to have been created. In many instances it's unquestionable that the stars themselves, the supposed habitation of other kinds of orders of intelligence, intelligent beings, together with different planets by which it's probable that they were surrounded, by which it's probable that they're surrounded so saying that he speculating that most of these stars probably have planets themselves which we now know is true they've utterly vanished in the spots which they occupied in the heavens have become blanks and what has befallen

other systems will assuredly befall our own of the time in the manner we know nothing but the fact is incontrovertible. It's foretold by revelation. It's inscribed in the heavens. It is felt through the earth. Such is the awful and daily text. What then ought to be done? What then ought to be the comet?

The great and good Beza. Beza, falling in with the superstition of his age, attempted to prove that this was a comet. or the same luminous appearance which conducted the Magi or the Wisemen of the East into Palestine at the birth of our saviour. And that, get this, it's now up here to announce his, announce his second coming. And then here, this is the supernova remnant from 1604. so at the time of the writing of this book, it was a little over 200 years old. So about 220, maybe 230, we'll say.

Because this was written in 1833 originally. And he says about 6 degrees northwest of CAF. The telescope reveals to us a grand nebula of small stars, apparently compressed into one mass or a single blaze of light with a great number of loose stars surrounding it then it goes into a history of cassiopeia cassiopeia was the wife of syphias king of ethiopia king of ethiopia of indromeda

she was the queen of matchless beauty and seemed to be sensible of it for she even boasted herself father fairer than juna the sister of jupiter or of narratives a name given to the sea nymphs this so provoked the ladies of the sea that they complained to neptune of the insult who sent who then sent a frightful monster to ravage her coast as a punishment for her insult But the anger of Neptune and the jealousy of the nymphs were not thus appeased. They demanded and it was finally ordained that Cassiopeia should chain her daughter Andromeda, Whom she tenderly loved to a desert rock on the beach and leave her exposed to the fury of this monster. She was thus left in the monster approached.

But just as he was going to devour her, Perseus killed him. The savior youth, the royal pair confess. Heaved hands, their daughters, bridegroom bless. And speaking of Andromeda, I think on just a couple pages. Yeah, there we go. Indromeda. right there we're gonna uh we'll eventually get to it they talk about the little interesting nebula oval shaped in the indromeda constellation that we know today to be the two million year

two million light year distant and comparably sized galaxy nearest to us. So this this queer little nebulous bull-shaped dust oddly organized in a compact shape with with light peering through I believe he said it appearing as though it's being projected through a horn this odd little you know just a just a little side note that you can observe ends up being a massive galaxy right next door. So a great number of stars have been observed whose light seems to undergo a regular periodic increase in diminution or decrease. They're properly called variable stars. So he's saying that maybe the other one that we talked about were in that category. The Nova Cervoir.

weren't but so yeah they didn't have the designation of supernova but he's saying the for certain absolutely these next stars down here he's about to mention they fall in the category of regularly variable stars one in the whale has a period of three hundred and thirty four days and it's remarkable for the magnitude of its variation. From being a star of the second magnitude, it becomes so dim as to be seen with difficulty through even powerful telescopes. Some are remarkable for the shortness of the period of their variation. For instance, algal, as a period between two and three days, algal, Algo, Algal.

Delta Cephe of five in a third days, Beta Lirae of six and two-fifths days, Antinoy, and Tenui of one week. Beta in the constellation Percy. Perseus. So beta-Persei, know colloquially as the demon star, is a bright, multiple star. in the constellation of Perseus and one of the first non-nova stars, non-nova variable stars to be discovered I I wanted to show you guys this one because it's really like amazing how many stars can be gravitationally locked with one another because I usually I think you know a binary star is pretty cool and then you add a third star in there and it's like

That seems like there's it seems like it would be an unstable orbit Yet this algal here and will be coming across quite a few others Just as interesting in my opinion Is a three star system? And we're gonna see others with even more stars in them so consists of beta Perseille Percy A, A-A-1, A-2, and A-B. So what that meant is that, um, originally they thought it was a binary system,

and of course as our lenses and our ability to observe, get more and more fine-tuned and advanced, we're able to resolve sometimes entirely new stars orbiting these. And what was a binary, now as a trinary. system multiple star system so algal is a three star system contending consisting of beta perciay a a2 orbiting each other and then that binary system is orbiting percy a a b in which the hot luminous and binary primary beta percy a okay so a a one is hot and luminous and primary meaning

gravitationally dominant, more massive. AA2, Beta Percy, AA2, is cooler and fainter. And those two regularly pass in front of each other and cause an eclipse. So Algal's magnitude is usually near constant at 2.1, but regularly dips to 3.4, meaning larger magnitude number, larger number means fainter every 2.86 days during the roughly 10 hour long partial eclipses and here we have a I'll play it right now let's see yeah super cool visual off Wikipedia this is the interpolation of the orbit of AA2 around

a a a one and the four what's amazing is that the four frames at the top are transposed onto the graphic at the bottom. So that's real data, actual visual data that they collected. And then they're able to, you know, I guess mathematically change the perspective. So you can see what it might look like from, you know, above. above it above the system so so amazing above that I didn't address yet we have the light curve of Delta Cephea showing magnitudes verse pulsation phase pulsation phase pulsation phase means here's a better visualization of it I guess now go A and B and then Algo C is more distant

And that's a, those are just the images without the graphics showing you. That is pretty amazing. Says this animation was assembled from 55 images from the Chara Infra-Inferometer in the near-infrared H-band, sorted according to orbital phase. Oh, okay, good, good, good, good. Because some phases are poorly covered, A2 jumps at some points along its path, so. I'm not able to track it exactly every time, but, uh, so pulsation phase. So anyways, you could see its magnitude regularly increasing along its phase. An ancient Egyptian calendar, and this is gonna, we're gonna bring this up in a later episode,

because I don't think I'm gonna be able to get into the binary clusters and nebulae. today or at least yeah yeah binary because he the second and of our four sections I was going to cover today now looks like I'm only going to be able to do section one but um is binary stars or double stars as Burritt called them without realizing that most of the stars he put as variable stars do fall in that category because they are extrinsically invariable, meaning that they appear to vary in luminosity, just because of our vantage point. In other words, they wouldn't if we were looking at them, if our solar system was oriented such that we were above them and looking down, and therefore the binary or their planetary disks didn't obstruct our view of them.

So it's just interesting that, again, one perspective of this is we're seeing how the science of astronomy has evolved. And as a testament to how old the known observation of algal is, ancient Egyptian calendar of lucky and unlucky days composed 3,200 years ago, so 1200 BC, which happens to actually be right around the time of the Bronze Age collapse, that the real famous lecture by Eric Klein that's going around on YouTube. So it's interesting, but anyways, so this ancient Egyptian king, calendar of lucky and unlucky days composed 1200 BC is claimed to be the oldest historical document of the discovery of Algoal the association of Algoal with a demon-like creature the gorgon in greek

tradition or ghoul in Arabic tradition another word we get from them suggests that its variability was known long before the same 17th century. Here I just had two examples of extra galactic supernova that we know about. Here's supernova in 1994 D, meaning it's the fourth one A through C had already been seen. Look at this. This is a distant galaxy and that bright spot is on the outskirts of the galaxy. and is outshining the entire galaxy. It's host galaxy that it's native to. It's just hard to really understand

just how much power, energy goes into that. And then here, here's one from this year, actually. I forgot that it was. Supernova. 2020 JFO from Galaxy Messier 61 52 million light years away taken from an by an amateur astronomer we have a just a graphic not actual data but a graphic of binary stars and how the brightness decreases as they eclipse each other you can see it dips small dip is when the small

star passes in front of the large dimmer star the large large dip is when the more luminous tightly compacted star is eclipsed by the larger less luminous star so in other words right at the base of the trough right there pretty much represents the solo you know individual brightness and magnitude luminosity of the large probably red giant in this case because it's completely covering the light from the smaller star and so to finish up our section on variable stars here I'm so happy with this book this book so awesome such a piece of history so that was a Algoal and then he you know gives the other examples of the other short period variable stars

a few of which are binary themselves for instance let me look up Delta Sefi Delta Sefi can show you guys right here is the Bayer destination for a quadruple star system so as four stars less than a thousand light years away too pretty close in Galactic terms. At this distance in the visual magnitude of the star is diminished by 23% as a result of extinction Extinction caused by gas and dust along our line of sight. In astronomy, extinction is the absorption and scattering of electromagnetic radiation by dust and gas between emitting astronomical objects in the observer. So this is the

the, and I should have recognized that too, I was dumb. This is the prototype of the sepheed variable, which is monumental for the history of astronomy and, you know, humanity, really. Sefied variable stars is the prototype for the sephid variable stars that undergo periodic changes in luminosity. So it was discovered to be variable by John Goodrick in 1784. It's popular, I mean, popular, it's important. It's important because I know general, I was trying to get a more specific explanation, but generally it's important to history because it allowed Edwin Hubble to classify very accurately the true distance of was in the

drama andromeda nebula it was he was able to based on the standard characteristics of this type of star this specific type of variable star known as a sephean variable because of this particular one right here being the first of its kind found it was in the sepiae a Cepheid Nebula constellation, so that's how it got its name. Because of the predictability and regularity of luminosity, whenever one is found, essentially the period, or its frequency, of variation in luminosity is directly, is found to be directly proportional to its intrinsic

brightness. So whenever one of these is found, as long as we have a maybe through parallax, you know, looking at it and physically being able to use geometry, mathematically, I guess,

to determine its distance from us, we were able to have a standard candle and understand a, understand how bright or luminous a sephid variable appears.

at a specific distance and once we knew that we compared all other sepheed variables to that known that one with a known distance and the Hubble found a sepheed variable that he thought was a supernova until he observed it long enough and recognized that it didn't hit its peak and diminish forever like a nova would but it actually had a sepheed variable a regular variable a reoccurring variable luminosity like all variable stars do. He then was able to recognize that that was in a nebula or galaxy. Once he recognized that it fit the characteristics of a Cepheid variable, he was able to determine based on its luminosity compared to a, closer variable of known distance from us that that variable was not just hundreds or thousands of light

years that most objects in the early night up to the up to the early 1900s were thought to be but this was millions of light years away so the discovery of a sephid variable allowed Hubble and other astronomers, but most famously Hubble, to essentially revolutionize our perception of how distant and then thereby vast the universe really is, and how distant objects like galaxies were. And if they really were millions, not just thousands, but millions and millions, maybe even billions, of light years away, if we could see them at that distance, of course. That meant that guys like this were able to obviously figure out that they were large,

but, you know, extraordinary leaps of scientific and astronomical hypotheses and theories. about how the universe really works. So more specifically, again, it's just cool that he named it, you know, as just an interesting star, you know, interesting variable star that has a short period as one of the most important sources of cosmic information about the fundamental workings of the universe. He says, so yeah, Delta Cepheid, which explains its brightness and noticeability, I guess, is among the closest stars of this type of variable to the sun, with only Polaris being near. Its variability is caused by the regular pulsations in the outer layers of the star. It varies from magnitude 3.48, the period of this class of variables.

variable is dependent on the star's luminosity. Delta Cepheid is of particular importance as a calibrator of period luminosity relationship since its distance is now one of the most precisely established for a Cepheid and I always wondered like because you always hear that when you're hearing about Hubble's breakthrough discovery of the universe in its size and galaxies because before that, we thought the universe was just one mass of star. We thought essentially the Milky Way galaxy was all there was. We thought everything we saw in the sky was a part of our gravitationally bound group of, you know, galactic stars. We didn't consider a galaxy as a individual.

island grouping of stars that is just one of trillions out there and so that was a phenomenal leap and but they never quit they always kind of seem to gloss over in popular science the method in how Cepheid variables actually were able to tell scientifically speaking how distant you know they were and that's it is that somehow they have a very stable and predictable and reoccurring relationship between how bright they get and the duration the time it takes from each peak of brightness it takes to undergo one cycle of variability and brightness essentially and because it's so close when Earth is going around the Sun when Earth is on opposite sides of our orbit we're

able to look at the star and then six months later look at it again from a distance of twice the radius or one diameter one Earth one orbital diameter away from where we measured it six months prior being about roughly 190 million miles apart I guess that gives us enough of a change in position in the cosmos to see a tiny shift of stars position with respect to much further much less changing stars in the background to finish up our section on variable stars the The regular succession of these variations precludes, meaning prevents the assumption of, the supposition of an actual destruction of the stars.

Neither can the variations be supposed to arise from a change of distance, for as the stars invariably retain their apparent places, it would be necessary to suppose that the, they approach to and recede from, the earth in a straight line, which is very improbable. In other words, for the change in luminosity of the variable stars to be explained by a change in distance, you know, like a car, a headlight gets brighter when it's coming toward us. That would mean just that, that it is like traveling down a highway towards and then from us

in a variable pattern, which is very unlikely. star, you know, orbiting with, you know, all these other stars. This one, you know, one particular star just happens to be oscillating in a perfectly straight line. I like how he uses practical reasoning like this, saying it would have to be moving away and towards us in a straight, a perfectly straight line because it doesn't in our from our reference frame it isn't moving with respect to the background stars at all you know except for really close stars like alpha centauri and you know the sephid variable that we're able to very minutely subtly detect um i just love that they he's showing how astronomers originally reasoned and nowadays we have advanced technology to

confirm the results of the right reasoning earlier but back then you had some data very limited with a very crude telescopes you know for the most part relative to you know orbiting telescopes like the Hubble nowadays and you had to use logic and rational lines of reasoning to guess and theorize and that's something that a lot of these modern textbooks fail to do i think i think teaching comes best from understanding how we arrived at all this information that we apparently know about the universe and uh when you just dump it on a first-year student as though it's all self-explanatory I think that kind of discourages people from wanting to engage in critical critical thought

you know the most probable supposition is that the stars revolve like the suns and planets like the sun and its planets, about in axis. Such emotion, says the elder Herschel, who discovered Uranus, maybe as evidently proved as the diurnal motion of the earth. Dark spots or large portions of the surface, less luminous than the rest, maybe, turned alternately in directions either towards or from us, you know, rotating. will account for all the phenomena of periodical changes in the luster of the stars. So satisfactorily, they'll account for this, that we certainly need not look for any other cause.

That's a great example of bad reasoning. So Herschel was so convinced that because we saw some spots on our own sun, all the other stars must have them and they might. But he was so convinced that that was a good enough solution to the issue of variability in stars brightness that this guy picked up on it because he's a prominent. Herschel was a prominent figure in astronomy and So he hadn't really considered that Perhaps there was more dynamic phenomena that are intrinsic to the star or maybe that there are entire stars other stars orbiting the systems that are eclipsing the star itself making it dimmer and

you know all the other ideas we talked about being um whether it's nebulae or you know nebulous proto stellar clouds of matter orbiting protoplanetary I guess clouds of matter orbiting the star and what was the other one yeah I guess just like Cepheid variables outer layers that are just periodically oscillating in luminosity so I guess yeah that about we'll wrap it up for today with our section on variable stars thanks again to my sponsor Manta's sleep I hope you guys do try him out they're really just a wonderful product so to be honest I'll I'll gladly promote them anytime in the future and there were also a nice little cherry on top was that the

representative I was working with was just she was very very pleasant to talk to so yeah I guess this is a better view here you guys can see it It's got a nice little Velcro strap. A little too loud to open now, but you can adjust it. Their phrase is infinitely adjustable, and that is true. You can make it fit you exactly. It's super comfortable, and the material is super soft, very soft. So anyways, that does it for part one of four, at least of four sections.

You know, maybe I'll try to do more than one section in the next video. But, uh, until then, as always, thanks for tuning in, guys. I don't know why I say that. I do enjoy all your comments. Uh, you liking the video, subscribing obviously, lets me know, uh, you enjoy the content. I really thrive off compliments and feedback and, um, constructive criticism. So you guys let me know what you liked, what you didn't. And I'll see you guys next time while we're figuring out more about astronomy from 1836.