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Astrophysics

- The branch of astronomy that deals with the physics of the universe.
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HELPFUL DESCRIPTIONS. a : semimajor axis For elliptical orbits, the semimajor axis is half the length of the...
May2-10 02:49 PM
Jenab6
45 68,015
To help me in understanding this procedure, I read the fifth chapter of THE DETERMINATION OF ORBITS by A. D. Dubyago,...
Apr22-12 12:10 PM
Drakkith
20 45,377
Hello Folks, I have an interesting question (I think)... how far back in the history of universe would you have to...
Oct21-12 08:05 AM
mfb
38 6,863
Hey folks, A couple of weeks ago I took a photo of the moon, not sure if you will be able to see this in the image,...
Nov5-12 05:20 PM
paddys09
13 1,729
From an early age I thought that scientists knew what gravity is, the actual thing and not just the effect it has on...
Nov4-12 09:20 PM
Drakkith
21 4,350
I have been having a conversation via email with someone who adamantly agrees with the statements of geocentricism. My...
Oct6-12 08:17 AM
mfb
6 1,368
Hi all Looking for some assistance if possible. Astrophysics is not my field--so please be gentle with me, as I...
Oct19-12 07:38 AM
Drakkith
4 1,470
I know the title sounds stupid, but I have a serious question. If you look at the simulations for the massive...
Oct19-12 10:10 AM
marcus
4 1,182
Hello everyone, I come here with a question. I'm not a physicist, so this might be a stupid question. But...
Oct20-12 05:14 AM
tiny-tim
1 926
Hope you enjoy the following, http://www.youtube.com/watch?v=_Ssc1GsqHds&feature=player_embedded From, ...
Nov3-12 11:37 PM
SpaceDreamer
5 1,422
I have a thought whilst in the shower this morning, it is usually said that shock waves only take part in star...
Oct31-12 05:51 PM
hunt_mat
3 823
The escape velocity on Planet X is the speed the rocket needs in order to never fall back down again in a universe in...
Oct31-12 10:37 PM
Vadar2012
6 1,061
Description: An extrasolar planet can be detected by observing the wobble it produces on the star around which it...
Nov5-12 11:20 PM
nick21324neo
0 2,233
Hello all, this is my first post. My question is, do any theories exist about time relativity based on distance from...
Nov11-12 10:17 AM
ksertatas
6 1,375
If dark energy repels things at the speed of light, does that mean if light energy is produced near it, it would repel...
Nov11-12 09:32 PM
marcus
2 1,219
how can black holes bend time if time bending is impossible ?
Nov11-12 05:15 PM
tiny-tim
3 1,556
doesn't that mean that one hemisphere would have a hotter summer than the other hemisphere and the opposite would have...
Nov13-12 01:10 AM
willem2
2 989
We can determine what kind of elements exist in different planets by observing electromagnetic waves from planets'...
Dec3-13 03:43 PM
Solon
16 2,834
Hello All, I am trying to understand how stars are formed and thereby came across Jeans instability. I am new to...
Apr26-13 05:58 AM
shounakbhatta
3 696
As far as avoiding a killer asteroid in the future, I have what I consider to be a simple solution. Japan has already...
Dec10-13 04:10 PM
tinypositrons
35 3,545
How does the Oberth Effect work, and why? Why would acceleration applied at one point in an orbit be different from...
Dec8-13 08:54 AM
mrspeedybob
3 1,323
Hey I'm trying to find out the maximum velocity that ISON had, should I use Newtonian physics or general relativity...
Dec5-13 09:32 AM
ilikescience94
24 2,098
Do we have any evidence that either: 1. There exist stellar black holes which orbit supermassive black holes in...
Dec1-13 05:27 PM
EskWIRED
3 902
What are the odds that there is a different event horizon for dark matter?
Dec1-13 10:09 PM
Drakkith
1 789
Given: According to my reference (An Introduction to Modern Astrophysics), I should start with this equation: r =...
Dec2-13 09:20 AM
ecastro
0 846
I asked a question recently about orbiting black holes. Thanks for the answers. So if I'm correct in my thinking,...
Dec15-13 12:48 PM
phinds
7 1,218
Do you have to "stick to the left of your orbit" or "give way to the unmanned vessel"?
Dec10-13 02:19 AM
tinypositrons
3 977
Hi, I try to solve excercises from the book Stellar Atmospheres by Mihallas. I'm stuck on this one: By use of...
Dec8-13 05:09 PM
lakmus
0 853
People are saying that Kepler 22b looks like it may harbour life. How could we ever know? I was just wandering, but...
Dec10-13 06:34 PM
Astronuc
2 891
Assuming that an object in orbit has no means of propulsion (dead satellites, NEOs, etc.) and it remains aloft long...
Dec14-13 09:12 PM
tfr000
2 922
Plasma-fire Unlike a (normal) fire, a plasma-fire combusts at excess 10 billion Kelvins (in general terms, 3.8...
Dec17-13 09:31 PM
berkeman
9 966
Sorry, strange question, but let's do a thought experiment: if a train was moving at near light speed and hit a slow...
Dec22-13 02:43 PM
Drakkith
9 990
I was wondering at what temperature would Titan's atmospheric particles reach escape velocity? Since Titan lacks the...
Dec19-13 07:39 PM
mfb
1 908
In the big crunch scenario, matter would clump together faster and faster, could a blob of this matter form a black...
Dec28-13 06:06 PM
ikjyotsingh
5 1,586
Could you please clarify for me how much each of these contribute to the red shifting of light from distant objects? ...
Dec22-13 11:33 PM
Bobbywhy
2 916
meteorites that are not large enough to reach the ground vaporize in the atmosphere (as do large portions of the ones...
Dec29-13 01:03 PM
OmCheeto
1 697
If we define the density of a black hole to be it's mass divided by the volume within it's event horizon then as the...
Dec30-13 02:28 AM
Chronos
2 830
Since we can observe gravitational lensing and conclude that mass can affect the path of EM radiation it seems logical...
Dec29-13 01:22 PM
Jonathan Scott
1 796
Since Nebulae are in "cloud" like structures, why does it not form itself into a sphere based on the highest density...
Jan17-14 02:21 AM
davenn
2 779
Hello, all. I'm trying to find an equation to determine a star's absolute magnitude in order to populate a table of...
Jan16-14 09:26 AM
ckirmser
1 599
It would be greatly appreciated if someone could help me solve this problem. There are two objects, let's call them...
Jan19-14 11:00 AM
Jonathan Scott
7 876
hello everyone like the prevailing theory now on how our universe origin has taken is THE BIG BANG. BUT i am...
Jan31-14 02:28 AM
dheeraj
4 608

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