HELPFUL DESCRIPTIONS.
a : semimajor axis
For elliptical orbits, the semimajor axis is half the length of the...

May210 02:49 PM
Jenab6

45 
67,767 
To help me in understanding this procedure, I read the fifth chapter of THE DETERMINATION OF ORBITS by A. D. Dubyago,...

Apr2212 12:10 PM
Drakkith

20 
45,191 
Blueshifted Galaxies
Why are the blueshifted galaxies located pretty much in two directions in the sky about 180º...

Dec2609 01:38 AM
matt.o

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...

Jan1010 05:33 PM
utku

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...

Dec2309 10:43 AM
Unto

8 
6,660 
http://www.science27.com/forum/g2.jpg
http://www.science27.com/forum/g1.jpg
At radius 1: Acceleration Due to...

Dec2709 02:28 AM
kjohnson

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...

Dec2809 03:56 PM
twofishquant

38 
8,602 
Hawking radiation is supposed to emanate from black holes because black holes have a temperature. A black hole has to...

Dec2309 02:01 AM
Ranku

8 
2,145 
I have a very little understanding of astrophysics. I wanted to know what kind of transmission bandwidth can travel...

Dec2009 10:26 PM
DarkStar707

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...

Dec2109 08:43 PM
Unto

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...

Dec2309 10:44 AM
Unto

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...

Dec2209 01:53 PM
Eden27

2 
1,057 
I understand that planets orbit follows a curve in spacetime created by the sun. Most of the planets follow the curve...

Dec2209 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...

Dec2209 02:54 PM
charon

0 
1,306 
Are these five names
cosmological constant, dark energy, vacuum density, vacuum energy, vacuum energy density
names...

Dec3009 12:47 PM
gravityboy

9 
4,557 
The perihelion of Mercury precesses by 5600 arcseconds per century, which is 43 arcseconds per century more than...

Dec2509 01:18 PM
Nabeshin

1 
1,568 
I have recently finished "Gravity from the Ground Up: An Introductory Guide to Gravity and General Relativity".
...

Dec3009 09:17 AM
Paul_Bartosik

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...

Dec2609 03:19 PM
D H

5 
2,669 
I have researched a bit, not extensively, the Bullet Cluster phenomena and why we believe the lensing to show that...

Dec2609 04:53 PM
cbd1

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...

Dec2709 04:04 PM
Ich

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...

Dec2809 03:34 PM
manjeet85

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?...

Dec3009 01:07 PM
edpell

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?...

Jan610 11:49 AM
denseguy

6 
3,003 
there was a singularity, what made it expand
i so confused

Jan610 01:03 AM
mugaliens

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...

Jan510 01:15 AM
pmehnati

3 
1,383 
Hello everyone :) I hope this, my first, question here on this forum lives up to it's standard. I try :)
...

Jan310 03:58 AM
JEL

0 
925 
Many years ago we started broadcasting radio signals for terrestrial use which inadvertently also radiated out into...

Jan310 05:52 PM
waht

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...

Jan610 07:36 AM
sylas

6 
1,626 
The preprint on this has not come out yet. What we have is a 5 January blog entry by Sigurdsson....

Jan710 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...

Jan1210 05:06 AM
!kx!

5 
1,706 
http://news.bbc.co.uk/2/hi/science/nature/8444038.stm
Apparently the Milky Way is at the centre of a rugby ball of...

Jan710 09:24 AM
Carid

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...

Jan710 01:55 PM
mheslep

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...

Jan1110 12:29 AM
russ_watters

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...

Jan810 11:19 PM
Aeronaut

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...

Jan1210 02:48 AM
cristo

4 
4,014 
hi!, just wondered what exactly is a singularity?
yes i could google it, but i figured you guys were smarter.
on...

Jan1210 02:08 AM
C.Braestrup

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...

Jan910 02:10 PM
lavenderblue

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...

Jan1110 11:54 PM
Chronos

3 
1,879 
Are there any different testable predictions of the DM (WIMPs) having different spin: 1/2 or 1?
For example, if DM...

Jan1310 10:01 AM
Dmitry67

8 
1,947 
Hi,
I'm trying to understand how exactly a black hole fits into the evolution of red supergiants, especially in...

Jan1210 11:58 AM
durand

4 
1,354 
Hi,
Ok, so i posted this on another forum and got a lot of different answers. My main question is:
Imagine...

Jan1410 04:25 PM
Matterwave

7 
2,149 
Light appears to travel at a constant velocity in a constant medium/matrix. According to Einstein, gravity is the...

Jan1410 08:09 PM
Matterwave

3 
1,086 