ask me anything astronomical

Bloody hell, you really are a keenkid.
Ok, what are gamma ray thing-a-ma-bobs?

And also, what's this Sedna planet they're all talking about, is it a planet or an astroid? (I could just google, but the oh so clever one wants questions...)

Originally posted by LadyCool21
Ok, what are gamma ray thing-a-ma-bobs?

sorry this took awhile... i've been working final papers and studying (hence why i want questions, to further my procrastination! ).

anyway, to answer your question, no one quite knows what gamma ray bursters are. well, other than gamma rays coming in excess at the earth. they can last from under a second to for over an hour. following this initial burst of gamma rays, there are always following x-rays.

they're, for all intesive purposes, the greatest mystery of astronomy today. they never occur in the same spot in the sky twice, for instance. no one really even knows what causes them. some theories are colliding blackholes, an explosion beyond that of a supernova (a super-supernova you could say), and neutron stars colliding or merging.

and if you're wondering... no, the radiation is not dangerous. the earth's magnetosphere does an awesom job of keeping us safe.

And also, what's this Sedna planet they're all talking about, is it a planet or an astroid?

i don't think anyone knows what a planet is. there's no clear definition. when the international astronomical union can finally agree on a defintion of one, we could end up only having 8 planets in the solar system, or nearly a dozen.

in my opinion, pluto is a planet. this is because it has a thin NO2 atmosphere and a moon, charon. granted, mercury as neither, but i still consider it a planet. anyway, it's been speculated that sedna may also have a moon. if it does, then i would consider it a planet as well. if not, then it's just a big hunk of rock way out there.

Wow, sorry I haven't replied sooner (I've been busy with coursework, but I've finished, yey!)

Also, what exactly is the connection with time travel and black holes? And is it technically possible? And why is it not practically possible at the moment?

Originally posted by LadyCool21
Also, what exactly is the connection with time travel and black holes? And is it technically possible? And why is it not practically possible at the moment?

the time travel connection is with the gravitational field. specifically if you were to orbit just outside the swartzchild radius (the "point of no return"). i would think so at least.

is it possible? i doubt it. it would be too risky, and without a doubt impossible to maintain an orbit so close to the black hole. another reason is that the nearest blackhole is lighyears away, and we haven't even left the solar system yet.

thumbs up for pretty much stumping me

Astronomical Fractions are founded on what Number?

Originally posted by Sapphire
Astronomical Fractions are founded on what Number?

the second. 1/60 is one second of one minute, 1/3,600 is one second of one hour, 1/86,400 is one second of one day, 1/31,536,000 is one second of one year, and so on.

Wow, thanks for the answer cmdrkeenkid, next time I watch Enterprise I'll have alittle more knowledge of what they're on about...
And I gave a stumping question, Mwhahahaa I am so clever (shh, we don't mention the unintentional hard question asking bit).

Originally posted by LadyCool21
Wow, thanks for the answer cmdrkeenkid, next time I watch Enterprise I'll have alittle more knowledge of what they're on about...
And I gave a stumping question, Mwhahahaa I am so clever (shh, we don't mention the unintentional hard question asking bit).

that's what i'm here for, answering questions. and i love being stumped, to be honest. it makes it more fun because then i don't have to rattle off info i just know from studying it and i actually have to think. but then again, i don't mind being asked "easy" questions because then i know i'm hopefully teaching someone something new. if that makes any sense.

as for enterprise, or any star trek episode. you know how when they go light speed the stars all streak by? as cool as that is, that wouldn't happen. the only light you would see would be the light that would be straight ahead of you, and that would just be a little spec. you probably already knew that, but i figurd i'd toss it out anyway.

anymore questions anyone?

One thing I never understood completely are topological defects. I didn't check the entire thread, but I doubt anyone has asked this. It's probably more cosmology than astronomy, but maybe you know something about them.

What are exactly topological defects (Topological Defects and Cosmology and Cosmology from Topological Defects)? How can they influence the large-scale structure of the universe?

Originally posted by amantine
One thing I never understood completely are topological defects. I didn't check the entire thread, but I doubt anyone has asked this. It's probably more cosmology than astronomy, but maybe you know something about them.

What are exactly topological defects (Topological Defects and Cosmology and Cosmology from Topological Defects)? How can they influence the large-scale structure of the universe?

so yeah, i know nearly nothing about this. it's something that i've really only heard of. and yeah, it's definitely more cosmology. i'll do some research and come back with a reply by sunday.... or maybe sooner, since i've got papers to type for friday and this thread was to feed my procrastination.

sorry i have no answer right now, but as i said. sunday at the latest you'll have one.

I never found a clear answer to amantine's question, and I still really don't clearly understand it all. I'm officially stumped, as I have been for the past however long.

I'm bumping this thread up due to its wealth of information and to *maybe* get somemore questions. Plus I'm adding it to the Space Exploration Serialized Threads thread.

[edit on 12/29/2004 by cmdrkeenkid]

hey my first question(s) here!!

What would it take for Jupiter to go stellar?
Increase in mass, density, volume, flammable matter??

Is there any legid non sci-fi refernce to 'white-holes'..?

An answer to one of the questions asked somewhere at the beginning of this thread..
"Is there proof that mass bends light...?"
1. It can be proven every time there is a solar eclipse, by measuring a slight but noticable shift in the position of stars whose light skims by the sun before reaching earth. The actuall posiotns of these stars are determined when the sun is not between them and the earth..

2. Something known as an "Einstein's Cross" or a "gravitational lens" can bend light in such a way that it forms a ring..Look up for pics of G2237+0305 and you'll see light from a quasar(distant) being bent by a much nearer galaxy..

3. Black holes are the best example of light being 'bent' by mass but one can't 'see' a black hole as such so thats a no go..

Originally posted by Daedalus3
hey my first question(s) here!!

What would it take for Jupiter to go stellar?
Increase in mass, density, volume, flammable matter??

Wasn't this already in this thread? I donno, really. Here's the answer though...

Jupiter alredy is stellar! (Since it's not on Earth and is in space. )

Sorry, had to be an arse. I know you mean for Jupiter to begin fusing Hydrogen into Helium and so on. Basically becoming a star, right? And it would take an increase in all the things you said, pretty much. To sustain fusion it would ahve to be about 80 times more massive and much denser. To increase this it would have to increase its size (volume) and it would need more fissible ("flammable") matter, which is basically Hydrogen.

Is there any legid non sci-fi refernce to 'white-holes'..?

A simple Googling could have answered this one! They're referenced to every so often. Here are a couple links...

What is a white hole?
White Holes and Wormholes

Thanks a lot cmdr...
I'll keep those Qs coming..

Exactly how many stars are there in the universe?

whats the distance in au and kilometres from earth to alpha centuari?
how long would it take to get there on a ride on lawnmower at 10 kph?
assuming it was a really good mower lol

Originally posted by instar
whats the distance in au and kilometres from earth to alpha centuari?
how long would it take to get there on a ride on lawnmower at 10 kph?
assuming it was a really good mower lol

More p recisely, one light-year is equal to 9,500,000,000,000 kilometers.
starchild.gsfc.nasa.gov... (first result with words "light" and "year" using Google)

Just drop one zero away and you get time in hours... to make it years divide previuus with result of 24x365.

And Alpha Centauri is ~4 LYs away so... you should be able to figure rest.

Originally posted by drunk
Exactly how many stars are there in the universe?

Claiming some exact number would be BS.
But here's good place to start:

How many stars are there in our galaxy?
curious.astro.cornell.edu...

How many known galaxies are there?
curious.astro.cornell.edu...

Originally posted by cmdrkeenkid
it would need more fissible ("flammable") matter, which is basically Hydrogen

PS. I think in this case its fusionable... after all we aren't splitting heavy atoms here, just hairs.

Originally posted by drunk
Exactly how many stars are there in the universe?

20.

This is an old thread.

How low toward the horizon can a solar eclipse occur?

I remember seeing a sunset eclipse in Dallas County, TX in 1999-2001. I've mentioned this to others and they say it's impossible. What say you, o astrophysical 8-ball?

PS. A friend turned me on to a website where the owner will print you a paper astrolabe, conformed to your lat & long and date. It's so cool! I've been fiddlin' with it all afternoon, waiting for sunset, so I can measure the stars. . . .

(see this is what happens when a geek gets interested in the history of science . . .)

Solar eclipses can occur at both rising and setting times.

Technically, it just depends on your location. The eclipse may be at noon at one point on the Earth and at sunrise or sunset at another.