Register to Post Thread

General Astronomy

- Celestial objects, space, and the physical universe as a whole. Astrophotography and amateur astronomy are welcome!
RSS Feed Icon Search this Forum
Meta Thread / Thread Starter Last Post Replies Views
aandc, library, reference Sticky Thread Pinned: A&C reference library ( 1 2 3 ... Last)
Use this topic to post links to helpful/informative websites about astronomy & cosmology.
Apr10-13 11:08 AM
139 89,125
Hi everyone Use this topic for posts about ongoing/upcoming stargazing events (e.g., comets, eclipses,...
Apr14-14 07:08 AM
282 104,740
astrophotography, photos Sticky Thread Pinned: Astrophotography photos ( 1 2 3 ... Last)
Looking for advice? Willing to share your expertise with other PF members? Brave enough to share & discuss your...
Dec12-13 08:47 PM
499 147,292
Hellfire requested that I post a list of classic papers that one could use for reference when trying to understand the...
Nov28-12 01:12 AM
17 38,657
We often have questions about what telescope an aspiring amateur astronomer should buy. The "correct" answer can be...
Apr9-14 07:52 AM
234 80,850
I saw the comet earlier tonight using 15x70 binoculars in the middle of a small city. It's a brighter than (and not...
Nov1-06 07:34 PM
Quadruple Bypass
3 1,495
"best known for his prediction of the return of SwiftTuttle, the comet associated with the spectacular annual shower...
Nov26-10 05:03 AM
0 917
Hey all, I haven't been alive for that long, so I guess my data probably isn't as good as it should be, but in my...
Feb28-13 12:23 AM
1 827
In the 1970's, we utilized the Arecibo Radio Antenna to broadcast a message to the depths of space in the hopes of...
Dec28-03 08:41 PM
Adrian Baker
52 7,260
I have always wondered about this. When we went to the moon how did we communicate back to earth? On the same...
Apr29-09 05:23 PM
4 1,179
I have two spectra that I'd like to compare. One is the observed spectrum of HD 93521, an O-type star commonly used as...
Jun3-09 10:45 PM
4 3,059
The whole business of dark energy or cosmological constant or quintessence is novel, unfamiliar, and nebulous....
Feb25-04 02:03 PM
1 1,821
SpaceTiger has created a very valuable thread on Mainstream Cosmology. For good scientific practice it is important to...
Jul18-05 03:56 PM
67 6,020
The planets in the solar system are almost complanary. I wonder why? I know it has something to do with their common...
Jul8-04 05:33 PM
6 1,229
Ignoring what we know. I was curious as to if anyone had overlayed all of the spectrum's of light on top of each other...
Jun13-10 05:22 AM
7 1,594
In our Solar System, how does the ratio of gas planets to terrestrial planets compare with that of gas moons to...
Dec26-10 06:13 PM
Loren Booda
5 1,547
Lets say there is an exoplanet 50 light years away. The radius of this planet is 2x Earths with 8x Earths mass and a...
Oct15-13 10:13 AM
8 1,278
What are Compton Recoil Electrons? I am thinking that it orginates from gamma-rays.
Jul9-05 03:45 PM
1 4,227
I wanted to add ths here for cosmlogical reasons :smile: I am open to corrections
Aug2-04 01:47 PM
0 1,114
I have recently read the november edition of Scientific American. The article says that everything computes. Bits...
Dec18-04 09:15 PM
1 1,160
In short: Why are galaxies flat? In more detail: A very large mass M is at rest in vacuum, rotating at point O....
Apr6-13 10:55 PM
9 1,326
Hi there, I have a question about something that has been bothering me for quite some time now: Doesn't the notion of...
May21-05 02:17 PM
5 1,509
Hello I am a student in high school and my physics teacher is a complete idiot. He just gave us a project to draw the...
May29-07 01:23 AM
2 2,372 How many cosmological parameters? Andrew R. Liddle Astronomy Centre,...
Mar19-04 08:39 AM
4 2,144
Are stars far away the same age as stars closer, or are they younger or older? And wouldn't the speed of light make...
Jan13-06 01:59 PM
10 1,326
I know that the bigger the telescope aperture, the more photons you can collect, and the fainter the objects you can...
Nov29-08 04:07 PM
9 1,474
hello new Gurus Congratulations to all! (and also to the many worthy second and thirdplace runner-up Gurus) PF is...
Dec6-04 06:22 AM
2 1,289
Turbo writes: It has been a bit over two years now, but our paper has been accepted at Astrophysics and Space...
May20-08 02:29 PM
10 2,200
Hi, and congratulations to all the PF gurus I have been interested for a long time in AGN unification, and I think...
Apr21-08 03:19 PM
dark matter
15 2,483 One of our own getting national press. Now maybe she'll stop lurking on...
Apr2-03 03:11 PM
17 3,159
Today an interesting question came to my mind... I have heard that when is a conjunction of planets to Earth, it...
Jan27-13 06:45 AM
10 1,818
I'm a physics major currently taking my first astro class. We're covering the basics at the moment but I am having...
Oct7-13 07:06 PM
3 1,526
Hey everyone, APOD just announced today that the consensus regarding the strange streak in the Australian picture...
Dec24-04 05:06 PM
2 1,045
Is it possible that the chicxulub impact is responsible for the earths magnetic pole being tilted 15 degrees off the...
Feb16-11 10:35 AM
26 4,692
First off, love the site and I use it all the time to get my mind working and I really appreciate everyone who puts...
Nov12-09 09:25 AM
3 1,828
Dark energy has a constant density as the universe expands. Doesn't this suggest that the baryonic mass of the...
May15-04 11:26 AM
4 2,654
Each month a different zodiac constellation follows around the sun day and night. The constellation is in the...
Sep28-10 08:39 PM
3 3,217
It is 20th October. 1. Does a point on Earth scans through all the twelve Zodiac constellations in 24Hrs? 2. Why...
Oct20-09 05:10 AM
3 4,831 Title: Constraints on dark matter and the shape of the Milky Way dark halo...
Jul12-05 04:39 PM
1 806
Hello, group! I'm wondering how to calculate the HZ for a contact binary system. Obviously, you can't use just...
Dec19-13 11:08 AM
3 876
When I think about an expanding and contracting universe I wonder if the eventual integration of black holes is the...
Aug19-04 05:00 PM
13 2,465
This should be very easy but I cant see what Im doing wrong... V_t=\mu .d where vt = tangential speed (in km/s) d...
Oct31-10 05:35 PM
2 2,821
Not that this is really an astronomy question per se, but astronomers are most likely to know the answer. I have a...
Jan17-11 12:07 AM
1 1,777
I need to convert the intensity, 130 counts per pixel into magnitudes per sq arc second. I have been given the radius...
Jan9-10 11:20 PM
1 1,822
Good Day Everyone, Been searching this site and the internet for over a week and have not found the answer to my...
Oct17-11 04:16 AM
14 4,188

Register to Post Thread
Bookmark and Share

Display Options for General Astronomy Mentors
Showing threads 1001 to 1040 of 5642 Mentors : 2
Forum Tools Search this Forum
Search this Forum :
Advanced Search