EPTA basic introduction to Astrophysics - Page 3
| Blogs > Teoita |
|
OtherWorld
France17333 Posts
| ||
Teoita
Italy12246 Posts
 Of course, more people adding to the discussion is always nice!On April 25 2015 08:48 Mordanis wrote: I thought quark stars are fairly likely. We haven't observed any black holes of less than about 5 Solar Masses, and the Chandresekhar Limit is something like 3 Solar Masses for a neutron star. That's true, but computing the degeneracy pressure for quarks hasn't been fully done yet to my knowledge, so who knows if it can actually support a collapsed core or not. For now it's a cool idea but it doesn't have solid observation or a complete theoretical background backing it up. On April 25 2015 08:11 fancyClown wrote: How have galaxy clusters and superclusters been confirmed? Is it just a matter of putting all observable galaxies on a 3D grid and looking at the interactions? Or is the concept of clusters based on unproven theoretical assumptions? They have been observed directly through galaxy surveys (observation campaigns that target thousands of galaxies) and, in the case of clusters, they can be spotted both in Xrays (the space between galaxies in a cluster is filled with gas that emits at those frequencies), as well as leave a "trace" in the CMB. When a CMB photon "hits" an (energetic) electron in a cluster, it can grab part of its energy, essentially disappearing from the CMB and leaving behind a cold spot in it. On April 25 2015 12:13 Ctone23 wrote: I watch "Into the Universe" all.the.time.. It's fascinating, I would love if you posted more about this! Curious, what do you make of the so-called "Supervoid"? Eh Stephen Hawking knows cosmology a bit better than i do That void is really wierd; it's reasonably simple to calculate how big structures like superclusters or super voids can be, as it's essentially tied to how much matter/radiation/dark matter/dark energy the Universe is actually made of. Anything bigger than that to our knowledge shouldn't exist, so yeah, i don't have an explanation. It's just another hint that we have a long way to go! On April 25 2015 16:12 Kommatiazo wrote: I can't even express how happy it makes me that this blog/thread exists on Team Liquid. THIS is why I love all you people. Teo, it'll be a few years yet before I'm employed as an astrophysicist, but maybe I'll see you around at a conference or something someday. I'll make sure I always wear my TL pin on my suits  Deal! | ||
|
marvellosity
United Kingdom36161 Posts
Astrophysics/cosmology/whatever tends to be the kinda area I get lost in when I accidentally look at wikipedia and end up with a zillion tabs open. | ||
|
Ej_
47656 Posts
| ||
|
Liquid`Nazgul
22427 Posts
| ||
|
Kommatiazo
United States579 Posts
On April 25 2015 22:40 Liquid`Nazgul wrote: I love people loving space. For me, it is just too big. That's why you just focus on one planet or body or something  | ||
|
Butterz
688 Posts
| ||
|
Deleted User 135096
3624 Posts
| ||
|
B.I.G.
3251 Posts
-How come stars don't burn out faster? Do they really have a big enough supply of flammable material (hydrogen?) that they can burn for billions of years or can they somehow replenish themselves? If so, how? -I once heard/read/saw that gravity is one of the three or four basic 'forces' or 'natural occurences' that helped shape the universe the way it is today (gravity allowing matter to clump up and form stars/planets rather than remaining the huge shapeless gascloud it was at the beginning right?). If true, what are the other forces? | ||
|
Teoita
Italy12246 Posts
The only way for a star to replenish itself is to be in a binary system, with two stars orbiting each other. In these systems sometimes one of the two stars will start stealing matter from the other, and adding that to its own mass. This impacts stellar evolution a bit, but it doesn't change how long stars are expected to burn that signifincanlty. 2) Electromagnetism, the weak force (which is responsible for some nuclear decays, called the beta decay) and the strong force, which is what binds protons and neutrons in nuclei. | ||
|
Aocowns
Norway6070 Posts
Quasars.. as far as I know they're some of the brightest and most luminous objects we know of(even outshining host galaxies?), and the energy comes from mass being sucked into a nearby supermassive black hole. But how are quasars formed, and are they observable from earth with entry level telescopes? 5 stars | ||
|
hypercube
Hungary2735 Posts
On April 26 2015 00:09 Kommatiazo wrote: That's why you just focus on one planet or body or something In Astronomy 1 at uni the lecturer spent 15 minutes describing different types of lunar craters, their classification by size and morphology and explaining their formation in detail. I love astronomy but I doubt I could care about something so specific as much. And I have to assume she was barely scratching the surface (no pun intended) of lunar science. | ||
|
Teoita
Italy12246 Posts
On April 26 2015 05:19 Aocowns wrote: God I love space, just learned some entry stuff in physics class Quasars.. as far as I know they're some of the brightest and most luminous objects we know of(even outshining host galaxies?), and the energy comes from mass being sucked into a nearby supermassive black hole. But how are quasars formed, and are they observable from earth with entry level telescopes? 5 stars None knows how quasars really are formed, if i knew the answer to that i'd probably win a noble prize. They are a particular kind of black hole accreting matter as you said; they are about 100 times brighter than your average, active (meaning "sucking matter") supermassive black hole. None knows for sure how those black holes form, or why some seem to accrete so much more than others, and why this seems to happen more often going further back in time. The brightest quasar has an apparent magnitude of 12.9, while depending on where you observe from (assuming you are close to a urban area) your limiting magnitide will be 4-8ish so unfortunately no, you can't see them with an amateur's telescope (higher magnitude means faint objects, it's a pretty silly system tbh). To be fair, without a badass telescope like Hubble all you would see is a luminous dot identical to any star. | ||
|
Cricketer12
United States13990 Posts
great blog Teo, all hail Hubble | ||
|
Cricketer12
United States13990 Posts
On April 26 2015 04:11 Teoita wrote: 1) Yeah, some stars can keep burning for billions of years. Once they are done with one phase of burning - say, converting hydrogen in helium - they can procede to the next phase, in this case converting helium in carbon. Generally, the more massive the star, the more elements it can burn (the bigger once can produce iron), but the quicker they burn out. The only way for a star to replenish itself is to be in a binary system, with two stars orbiting each other. In these systems sometimes one of the two stars will start stealing matter from the other, and adding that to its own mass. This impacts stellar evolution a bit, but it doesn't change how long stars are expected to burn that signifincanlty. 2) Electromagnetism, the weak force (which is responsible for some nuclear decays, called the beta decay) and the strong force, which is what binds protons and neutrons in nuclei. correct me if I'm wrong but aren't some of the larger (by atomic number) elements found on Earth created by dying suns? I believe I heard that in some documentary I watched | ||
|
Teoita
Italy12246 Posts
| ||
TheEmulator
28094 Posts
 | ||
|
Teoita
Italy12246 Posts
| ||
|
Ctone23
United States1839 Posts
Jk | ||
|
JieXian
Malaysia4677 Posts
one of the pillars does look like a cock though | ||
| ||
