Andromeda and the Local Group (go to 2020 4K edition)

visible to the naked eye and studied by persian astronomers around 900 AD the andromeda nebula was thought to be a part of the Milky Way in fact it was thought that all the stars in the universe were in our Milky Way galaxy that changed in the early 1900's in 1923 Edwin Hubble found a Cepheid variable in the nebula the star altered the course of modern astronomy the star goes by the name v1 here's Edwin Hubble's image of Andromeda which was made on a four by five inch glass plate and dated October 6th 1923 he originally identified three stars and marked each of them with an N for nova a class of exploding star later bubble realized that the Nova at the top right was actually a sea fiood variable he crossed out the N and wrote var for variable he added an exclamation point because he knew that this variable would allow him to calculate the distance and indeed once the period was measured at 31.4 days he knew he had another galaxy before v1 distances to stars were measured in thousands of light years after v1 the universe became a much bigger place v1 was over two and a half million light years away Andromeda is a beautiful large spiral galaxy with two spiral arms that glow with a massive number of new stars this is very much like our Milky Way but it is 220,000 light-years wide and contains around a trillion stars that makes it a good deal larger than our galaxy light from this magnificent galaxy left its stars just over two and a half million years ago when the light that entered Hubble's telescope left Andromeda there were no humans on earth while the light traveled towards Earth we came into being we created and lost great civilizations and we built the telescope that caught the light when it finally reached our planet you you here we see the 100 million solar mass black hole at Andromeda score this is the sharpest visible light image ever made of the nucleus of an external galaxy there is a blue glow at the centre of what appears to be a double nucleus astronomers using the Hubble Space Telescope have identified the source of the blue light surrounding the supermassive black hole new spectroscopic observations reveal that the blue light consists of more than 400 stars the stars are tightly packed in a disc that is only 1 light year across the disk is nested inside an elliptical ring of older cooler redder stars when the stars are at their furthest point in their orbit they move slower and this gives the illusion of a second nucleus there are 54 galaxies in the local group Andromeda is the largest the Milky Way is second and Triangulum is third all arrests are dwarf galaxies and most of these are orbiting one or the other of the three big ones the Milky Way has 16 satellite galaxies Andromeda has 25 satellites and the Triangulum galaxy might have one the other members of the group are gravitationally not orbiting any of these three large galaxies we'll take a good look at some of these and then move closer to home and have a good look at some of the dwarf galaxies orbiting us the Triangulum galaxy is the third largest member of the local group of galaxies the diameter of about 50,000 light-years Triangulum is home to around 40 billion stars as small compared to our 600 billion and Andromeda's trillion engi 604 the gigantic star-forming region lies in the outer Triangulum spiral arm this monstrous star birth region contains more than 200 brilliant blue stars with a cloud of glowing gas some 1,300 light years across that's nearly 100 times the size of the Orion Nebula by contrast the Orion Nebula contains just four bright central stars the bright stars in 6:04 are extremely young by astronomical standards having formed a mere 3 million years ago this small irregular galaxy is one of the Milky Way's closest neighbors and is considered prototypical of the earliest fragmentary galaxies that inhabited the young universe what's striking about NGC 68 22 is its unusually high abundance of h2 region emission nebulae these are visible surrounding the small galaxies particularly towards the upper-right this is one of them the glowing gas cloud called Hubble 5 as a diameter of about 200 light years a faint tail of nebulosity trailing off the top of the image sits opposite a dense cluster of bright stars at the bottom of the irregular shaped nebula I see 10 is another irregular galaxy Edwin Hubble suspected it might belong to the local group of galaxies but its status remained uncertain for decades his membership in the group was finally confirmed in 1996 by direct measurements of its distance based on observations of sea Fiats the reason took so long is that despite its closeness the galaxy lies near the plane of the Milky Way and is therefore heavily obscured by our galaxy's interstellar matter NGC 3109 looks like a small spiral galaxy if it is a spiral galaxy it would be the smallest in the local group it is oriented edge-on from our point of view and may contain a disk and a halo it does not appear to possess a galactic nucleus but it does seem to contain an unusually large number of planetary nebulae here's a satellite galaxy of ng 3109 it's a small irregular gumdrop shape dwarf galaxy the bright foreground yellowish stars are actually in the Milky Way beyond them lie the stars of sexton's a with young blue star clusters clearly visible this map shows the closest dwarf galaxies they are all gravitationally bound to the Milky Way requiring billions of years to orbit it Sagittarius dwarf is the closest it is so close that it is slowly being ripped apart by our galaxy Fornax is too farthest away but the two dwarfs of the most interest can be seen in the southern night sky they are the Large Magellanic Cloud 162 170,000 light-years away and the small Magellanic Cloud a bit further at 200 thousand light-years from us the Large Magellanic Cloud or LMC for short is the brightest galaxy in the sky it contains several billions of stars and many stars are still forming in it the small Magellanic Cloud or SMC for short contains at least several hundred million stars like the LMC there is still a lot of star formation taking place within it you may have noticed that as we went through our segment on supernovae in 63 a and 1987a were listed at a hundred and sixty thousand light-years away or greater that was further than the maximum extent of our galaxy that put these objects outside the Milky Way they were actually in the LMC dwarf galaxy here are a few more of the beautiful nebula in the LMC this image of supernova remnant zero five zero nine dash 67.5 was made by combining data from two of NASA's Great observatories Hubble and the Chandra x-ray Observatory the results show soft green blue hues of heated material from the x-ray data surrounded by the glowing pink optical shell which shows the ambient gas being shocked by the expanding blast wave on the supernova several million young stars are vying for attention in this Hubble image of a stellar breeding ground in 30 Doradus located in the heart of the tarantula nebula early astronomers nicknamed the tarantula because it's glowing filaments resembled spider lights 30 Doradus is the home to the most massive stars ever seen weighing more than 100 times the mass of our Sun no known star forming region in our galaxy is as large or as prolific as 30 Doradus the image reveals the stages of star birth from embryonic stars a few thousand years old still wrapped in their eggs two behemoths the die young in supernova explosions you Hadj 301 seen in the lower right hand corner of this image lies inside the tarantula nebula many of the stars in hajj 301 are so old that they have exploded as supernovae these exploded stars are blasting material into the surrounding region at speeds of almost 200 miles per second the high-speed matter is plowing into the surrounding tarantula nebula shocking and compressing the gas into a multitude of sheets and filaments seen in the upper left portion of the picture a unique peanut-shaped reflection nebula surrounds a cluster of young hot stars in this view from Hubble the double bubble and 30 B is inside a larger nebula the very bright star at the top of the picture illuminates the dusty cocoon like a flashlight shining on smoke particles this searing supergiant star is only 25 light-years from the N 30 B nebula swirls of gas and dust reside in this region of star formation it reveals a region where low mass infant stars and their much more massive stellar neighbors reside this is just one of the hundreds of star forming systems located in the LMC this region is a firestorm of raw stellar creation perhaps triggered by a nearby supernova explosion the three-dimensional looking image reveals dramatic ridges and valleys of dust serpent head pillars of creation and gaseous filaments glowing fiercely under torrential ultraviolet radiation the region is on the edge of a dark molecular cloud that is an incubator for the birth of new stars now let's take a look at a couple of objects in the small magellanic cloud at the heart of the SMC lies cluster NGC 602 the high-energy radiation blasting out from the young stars is sculpting the inner edge of the outer portions of the nebula slowly eroding it away and eating into the material beyond elephant trunk like dust pillars point towards the hot blue stars and are all telltale signs of their eroding effect the NGC 346 cluster at the center of this Hubble image is resolved into at least three sub clusters and collectively contains dozens of hot blue high mass stars more than half the known high mass stars in the entire SMC a myriad of smaller compact clusters is also visible throughout the region here are the local group galaxies we saw in this segment the local group is part of a larger structure known as the local volume we'll explore this local volume in our next segment

Channel: David Butler

Views: 1,196,993

Rating: 4.8462267 out of 5

Keywords: howfarawayisit, \how far away is it\, \david butler\, Andromeda, V1, Triangulum, \NGC 604\, \IC 10\, Sextans, Magellanic, \SN 0509\, Tarantula, Doradus, Hodge, \Double Bubble\, H-R diagram, red shift, Hubble, Spitzer, Chandra, ESO, telescope, STEM

Id: IhP1GnAvm0w

Length: 18min 10sec (1090 seconds)

Published: Sun Aug 18 2013

Reddit Comments

[u/NekkidTaco]

Cool band name

[u/orionrose]

Absolutely stunning. Thanks for posting this. I'm going to have to check out more of his stuff on YouTube.