ask me anything astronomical

so i was going to put this in Space 2015, but i figured since this is more or less to qualm my own boredom i'd better not. if a mod or someone feels it should be moved, well mod away.

anyway, so i want people to ask me astronomy questions. ask about anything... star formation, planets, stars in general, ask me to draw you an HR diagram for all i care. i'm really bored and up for a good challenge. whoever can stump me will get a... thumbs up!

so ask away peoples!

oh come on... someone must have some sort of astronomy question!

I posted this many many months ago, when I first came on ATS... nobody even made a suggestion as to what it was.

www.belowtopsecret.com...

All the information can be found at that link, called "What did I see last night?"

Good Luck! By the way, I thought you were great in Commander Keen Part 4...

i'm not sure if you're talking about the triangle that makes the head of persius, or the triangle called "kids" in the constellation auriga. all three constellations are in the milky way though (cassiopiea, persius, and auriga). that may have been what you were seeing actually.

the only nebulae and galaxies nearby would be the M34 star cluster in persius, m31 (the andromeda galaxy) and companion galaxies in andromeda, m45 (the pleadies) in taurus, and the m103 star cluster in cassiopiea. also, the bright star capella is in the region of the triangle "kids."

i'm guessing you saw m45, since it is visible by naked eye or capella. capella is one of the brightest stars in the sky. perhaps there was some upper atmosphere haze, giving it the image of a bright cloud, with dimmer companion clouds.

is this the sky you saw? i set it to your location whne i made up that image.

Checking your stuff... the night sky right now is about the same... only downfall is the global position... I'll be right back!

Since you have nothing else to do, could you please go over how stars and planets are formed?

I fell asleep during that section of my Earth 101 class.

It would appear to be M34, but the directions seem wrong...

The large triangle constellation was south of Cassiopia (that's the one shaped as a 3, right?).

The blurry cloud-like thing I saw was between the two... if memory serves correctly, ... nope... not serving today. I drew a rough map... I'll have to find it.

The triangle formation I found named in a pocket book of constellations. It was definitly called 'Tri----------------' something. It was a larger word, one I wasn't familiar with. Wasn't linked to any 'well known' constellation/myth formation.

Originally posted by surfup
Since you have nothing else to do, could you please go over how stars and planets are formed?

I fell asleep during that section of my Earth 101 class.

well, i can do stars. planets? not so much in depth. i'm no geologist. i could do composition, atmosphere, and some random facts though if you'd like.

Birth of a Star
- giant stellar clouds of gasses are compressed due to gravity and shock waves from supernovae. this forms bole globules, which are dark concentrations within a nebula that give rise to protostars. protostars are an early star just beginning to collapse together.

- these protostars then begin to collapse deep enough until fusion begins. then the star enters the t-tauri stage. this is a late stage protostar that works it's way to the main sequence. as it does this it sweeps out remnant dust and gasses, causing them to condense into other planets or if there's enough possibly another star.

- once the star enters the main sequence, it begins to fuse hydrogen into helium, and becomes one of several types of stars. a 10 solar mass star, such as a blue giant, takes 10,000 years to arrive on the main sequence. a 3 solar mass star takes 100,000 years. a 1 solar mass star (such as the sun) takes 30,000,000 years. a .5 solar mass star (such as a red dwarf) takes 100,000,000 years.

if you want me to go furth down the life of a star, just say so.

Originally posted by soothsayer
It would appear to be M34, but the directions seem wrong...

The large triangle constellation was south of Cassiopia (that's the one shaped as a 3, right?).

The blurry cloud-like thing I saw was between the two... if memory serves correctly, ... nope... not serving today. I drew a rough map... I'll have to find it.

The triangle formation I found named in a pocket book of constellations. It was definitly called 'Tri----------------' something. It was a larger word, one I wasn't familiar with. Wasn't linked to any 'well known' constellation/myth formation.

triangulum? maybe that's what you're thinking of. i think that's what it's called, at least. cassiopiea is "The W" in my map. i'd like to see what you drew. it'll help give me better insight. good luck finding it.

if you want me to go furth down the life of a star, just say so.

Could you please? Thanks

Originally posted by surfup
Could you please? Thanks

no problem what so ever. here goes.

Zero Age Main Sequence (ZAMS)
-once stars enter the main sequence, they have varied lifetimes, due to mass.
1 solar mass (such as our sun) -> 10 billion years
.5 solar mass (such as a red dwarf) -> 200 billion years
3 solar mass (smaller giant stars - under chandrasekhar limit. i'll get into that later) -> 500 million years
10 solar mas (larger giant stars) -> 50 million years

-there are two types of stars - population I and population II.

population I stars are newer stars that are "metal rich," meaning they have lots of chemical elements. they can be found throughout the spiral arms of galaxies. they're also stars that are several generations old, meaning made up of from remnants of many supernovae.
population II stars are older stars that are "metal poor." they can be found in globular clusters in the galactic halo, which is the space around the center of the galaxy.

most stars in this stage of their existence are variable stars, so i'm going to focus on them.

Variable Stars
variable stars are stars that very in brightness. in excess of 50,000 are known and more are discovered every day with new techniques.

there are several types of variable stars.
- eclipsing binaries -> binary stars where a dimmer binary star orbits around the main star, eclipsing it on view to earth. pretty much self explanitory by the name.

- pulsating variables -> two main types, cepheids and rr lyraes
- cepheids -> all F to G class stars on the main sequence going through the "instability strip." this is when a star is becoming a giant, and is pulsating rapidly as it expands and contracts. they have anywhere from a 2-100 day period of max to max luminosity, with the brighter the star the loner this period is.
- rr lyraes -> they are similar to cepheids, except that they are found only in globular clusters

- other variables
- long period -> red giant stars, with an 80-500 day period. they have a wide range of magnetude.
- semi-regulars -> red supergiants ending thier life. possibility to go supernova at anytime, basically.
- t tauri -> the newly forming stars

Sequence of Stellar Death
the mass of the star will seal its fate. with the deaths of more massive stars new chemical elements are created. as a star dies its fusion process has to go to higher and higher elements. this is the sequence of fusion (called chemsynthesis):
H -> He, He -> C, C -> Ne and MG, Ne -> O and Mg, O -> Si and P, Si -> Fe. when a star begins to fuse iron into higher elements is when it dies.

Death of Low-mass Stars (up to 1.4 solar mass)
- these are stars that are below the chandrasekhar limit. this is the limit which when a star above will go nova.
- when the helium to carbon process begins, the star expands into a red giant. when this happens to the sun, it will expand to nearly the earth's orbit. this swelling then lowers the star's density, but it also increases the luminosity due to the immense surface area.
- when the star reaches the silicon to iron process it blows off all of its outer layers (about half its mass) in a great stellar wind. this forms a planetary nebula. this stage lasts around 50,000 years. at the center of this is a white dwarf star.
- the white dwarf left over is a small, dense corpse that is only supported by degenerate matter, which is the mutual repulsion of electrons (likes repel). it's roughly 3 times the size of the earth.

Death of Medium-mass Stars
- medium mass stars are stars with a mass above 1.4 solar masses to 3.0 solar masses. they follow the same process of turning to red giants when helium becomes fused into carbon.
- when the silicon becomes fused into iron though, the star begins to collapse in on itself. this collapse triggers the HUGE energy release known as a supernova. this explosion fuses more elements from the iron in a fraction of a second. also, the intesnse temperatures at the core of the star fuses the electrons and protons into neutrons, creating a neutron star.
- a neutron star is equivilant to the mass of the sun shrunk into an area 10 to 15 miles in diameter. due to the extreme density there is a very rapid rotation, creating a pulsar.

Death of High-mass Stars
- stars that are above 3 solar masses
- instead of a neutron star forming, the star continues to collapse in on itself and forms a blackhole.

sorry this has taken me so damn long. i gave up on procratinating and am working on an english paper at the same time. if there's anything more or something you don't understand, just ask!

First, I'm curious if you build scopes.

Second, I'm trying to find McNeil's nebula, any advice on locating it? I know it's somewhere in orion, but where? Obviously backyard doesn't have it yet. lol

Peace,
BG

OK. If Jesus and Batman got in a fight, who would win? The fight would take place in outerspace(Astronomical part) and Jesus would be armed with a lazer sword. Batman would have his usual gear and the help of Robin. So, who would win?

Originally posted by beergoggles
First, I'm curious if you build scopes.

Second, I'm trying to find McNeil's nebula, any advice on locating it? I know it's somewhere in orion, but where? Obviously backyard doesn't have it yet. lol

Peace,
BG

i wish i could build a scope... the closest i have to that is a cookbook ccd camera my dad and i built a few years back. i do own a 10 inch meade schmit-cassegrain scope, an 8 inch reflector (optics are a dream come true!), and an 18 inch dobsonian.

as for mcneils nebula, i wish i knew where it was located. i haven't had a chance to observe yet since its discovery. i think it's either near the orion nebula, or somewhere on the belt itself. so you've got me stumped.

thumbs up for you!

Originally posted by NotTooHappy
OK. If Jesus and Batman got in a fight, who would win? The fight would take place in outerspace(Astronomical part) and Jesus would be armed with a lazer sword. Batman would have his usual gear and the help of Robin. So, who would win?

haha, wow... lay off the drugs... i'd have to say jesus though. why? i have no idea. now let's all just forget this has happened.

no problem what so ever. here goes.

Thanks. I have one more question, could there be multiple universes?

I remember my teacher saying that light is bend by matter, so even if there a more than two universes, we wouldn't see because the light from us won't reach them and theirs won't reach us.

Is this true? Are there any evidence to support multiple universe theories?

Thanks again.

OK. If Jesus and Batman got in a fight, who would win? The fight would take place in outerspace(Astronomical part) and Jesus would be armed with a lazer sword. Batman would have his usual gear and the help of Robin. So, who would win?

Without doubt Batman because for one I love Batman and I don't believe in Jesus or any other type of person who support religion, (opiate of the masses).

Originally posted by surfup
Thanks. I have one more question, could there be multiple universes?

I remember my teacher saying that light is bend by matter, so even if there a more than two universes, we wouldn't see because the light from us won't reach them and theirs won't reach us.

Is this true? Are there any evidence to support multiple universe theories?

Thanks again.

light is bent by mass, yes. that is a good theory that i'd heard as well. as for evidence to prove it? i don't know. in string theory there are multiple universes, but that's all it is. theory.

personally, i think that there are multiple universes. i dunno why, i just don' see why there couldn't be. everything is possible in my book.

thumbs up

Heres a fun one.

Barring long-period oscillations, what are 2 reasons the Average distance from the Sun to the Earth is increasing, and how much is the increase per year?

[Edited on 10-3-2004 by Kano]