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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
45 67,767
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
20 45,191
Blue-shifted Galaxies Why are the blue-shifted galaxies located pretty much in two directions in the sky about 180...
Dec26-09 01:38 AM
19 7,310
Hey guys. I have a few questions about black holes. First. Is it possible for there to exist a big enough object in...
Jan10-10 05:33 PM
12 2,040
A comet is observed to have a perihelion distance of 0.6Au and a period of 341 years. Calculate it's Aphelion...
Dec23-09 10:43 AM
8 6,660 At radius 1: Acceleration Due to...
Dec27-09 02:28 AM
18 3,858
Hi all, Apologies if my understanding is a bit simplistic but even if my question turns out to be idiotic, I'm sure...
Dec28-09 03:56 PM
38 8,602
Hawking radiation is supposed to emanate from black holes because black holes have a temperature. A black hole has to...
Dec23-09 02:01 AM
8 2,145
I have a very little understanding of astrophysics. I wanted to know what kind of transmission bandwidth can travel...
Dec20-09 10:26 PM
5 1,204
This one has me stumped: A galactic Cephid variable has a parralax of 0.002 arcseconds. What is it's distance in...
Dec21-09 08:43 PM
4 1,138
Venus's atmosphere is made up of CO2 which has a mean molecular weight of 44 atomic mass units. Given that the lower...
Dec23-09 10:44 AM
3 3,456
Are the images and data we collect of galaxies and other bodies millions of light years away millions of years old by...
Dec22-09 01:53 PM
2 1,057
I understand that planets orbit follows a curve in spacetime created by the sun. Most of the planets follow the curve...
Dec22-09 12:08 PM
Vanadium 50
3 1,167
I've been struggling with orbit calculations for Mars' moons and satellites. My Phobos and Deimos orbits look correct...
Dec22-09 02:54 PM
0 1,306
Are these five names cosmological constant, dark energy, vacuum density, vacuum energy, vacuum energy density names...
Dec30-09 12:47 PM
9 4,557
The perihelion of Mercury precesses by 5600 arc-seconds per century, which is 43 arc-seconds per century more than...
Dec25-09 01:18 PM
1 1,568
I have recently finished "Gravity from the Ground Up: An Introductory Guide to Gravity and General Relativity". ...
Dec30-09 09:17 AM
7 1,461
How can the kinetic energy of a rotaing planet be calculate? I know the KE equation, - but how can I calculated the...
Dec26-09 03:19 PM
5 2,669
I have researched a bit, not extensively, the Bullet Cluster phenomena and why we believe the lensing to show that...
Dec26-09 04:53 PM
0 1,658
Hello all. I am a newcomer on the forum and no major math or astronomy knower. But I have often thought about this...
Dec27-09 04:04 PM
3 1,983
Hi all, I need to get an aitoff all sky flux map. I have flux given by an equation that depends on different...
Dec28-09 03:34 PM
0 2,278
Let's say I have a 5m3 cube of air and right next to it a 5m3 vacuum. Does the cube of air have potential energy?...
Dec30-09 01:07 PM
7 1,250
I assume wind is also a factor but would the gravitational pull of the moon be the main force behind the oceans tides?...
Jan6-10 11:49 AM
6 3,003
there was a singularity, what made it expand i so confused
Jan6-10 01:03 AM
9 3,472
Hi At night when you watch moon in cloudy weather you will see the diffraction of moon light around it in circle...
Jan5-10 01:15 AM
3 1,383
Hello everyone :) I hope this, my first, question here on this forum lives up to it's standard. I try :) ...
Jan3-10 03:58 AM
0 925
Many years ago we started broadcasting radio signals for terrestrial use which inadvertently also radiated out into...
Jan3-10 05:52 PM
9 1,416
How do we know that observable matter is spread over a space at least 93 billion light years across the universe. How...
Jan6-10 07:36 AM
6 1,626
The preprint on this has not come out yet. What we have is a 5 January blog entry by Sigurdsson....
Jan7-10 03:20 PM
Frame Dragger
9 2,452
Magnetic diffusivity is a term that appears in the induction equation, when we deal with plasma fluids. It has units...
Jan12-10 05:06 AM
5 1,706 Apparently the Milky Way is at the centre of a rugby ball of...
Jan7-10 09:24 AM
0 1,104
I see from this pop press article that the ~nearby (3,260 ly) T Pyxidis is in a possible super nova end stage. For...
Jan7-10 01:55 PM
2 1,411
Hello This is my first post and excuse me I'm a bit dim (hence my username). So, I've had this question rattling...
Jan11-10 12:29 AM
9 7,312
I'm a newbie to astrophysics you could say, and I have had a few questions lingering around in my head. So in this...
Jan8-10 11:19 PM
2 1,057
First off, let me say that while I am an avid astronomer, I know very little about the mathematics of astrophysics. My...
Jan12-10 02:48 AM
4 4,014
hi!, just wondered what exactly is a singularity? yes i could google it, but i figured you guys were smarter. on...
Jan12-10 02:08 AM
4 1,264
I have just been asked to assume a new rotation curve for our galaxy. I have been given: \Phi = 402(a/r)^1/2 And...
Jan9-10 02:10 PM
0 942
Hi, I'm sure this has been tried but I was just wondering if it's possible to use the distribution of stars and...
Jan11-10 11:54 PM
3 1,879
Are there any different testable predictions of the DM (WIMPs) having different spin: 1/2 or 1? For example, if DM...
Jan13-10 10:01 AM
8 1,947
Hi, I'm trying to understand how exactly a black hole fits into the evolution of red supergiants, especially in...
Jan12-10 11:58 AM
4 1,354
Hi, Ok, so i posted this on another forum and got a lot of different answers. My main question is: Imagine...
Jan14-10 04:25 PM
7 2,149
Light appears to travel at a constant velocity in a constant medium/matrix. According to Einstein, gravity is the...
Jan14-10 08:09 PM
3 1,086

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