Reputation
1,361
Top tag
Next privilege 1,500 Rep.
Approve tag wiki edits
Badges
2 10
Newest
 Yearling
Impact
~7k people reached

2d
answered What must/do astronomers reveal beyond their academic papers?
May
19
answered What is a typical value for core-to-star efficiency?
May
3
comment Missing Terms in Weinberg's treatment of perturbations on Newtonian Cosmology
Uhm, I really can not see the reason... The only thing that come in my mind, is that the product of any operator nullifies. Perhaps, did you check that?
Apr
28
comment Missing Terms in Weinberg's treatment of perturbations on Newtonian Cosmology
What are $\vec X$ and $\vec q$?
Apr
28
revised Could our Sun be a companion star of a massive black hole?
edited title
Apr
28
comment Could our Sun be a companion star of a massive black hole?
"Can we track its orbit": does "its" stand for the Sun or for the BH? By "companion" you mean that the Sun is in a binary system? If so there are tens of threads about this already.
Apr
2
comment how to tell an optical spectrum is featureless or just with a low S/N?
Well, it wouldnt be bad if you could tell us what are these spectra about, where they come from, what do you expect there, which telescope took the spectra, if you can plot the background flux, and such "details". But no, let's put a picture and ask a 1-line hard question.
Mar
17
comment LIGO and Fabry–Pérot interferometer
Can you link some references?
Mar
17
comment Why do dark objects look white from a distance? (Moon, Ceres, but not Earth!)
Can you link such an image where the Earth does NOT shine as seen from the Moon? Just as a clue, why does the Moon is not always as bright as the full Moon?
Mar
8
comment Angular momentum in planetary disk formation
I suppose this is related with the formation of the system itself (the mass has to flow towards the inner region). Could you please link a reference where you read about the angular momentum condition?
Mar
7
comment How was Henrietta Leavitt's discovery important for star measurement?
Please, be more specific and edit your question if some of the links do not answer your (not yet formulated) question.
Mar
5
revised How do astronomers estimate the total mass of dust in clouds and galaxies?
added 413 characters in body
Mar
5
comment How do astronomers estimate the total mass of dust in clouds and galaxies?
@RobJeffries, thanks for pointing this out. What I meant is that, $N_H$ and extinction are related, therefore one helps to infer the other. I will edit my answer.
Mar
5
answered How do astronomers estimate the total mass of dust in clouds and galaxies?
Mar
5
comment How was Henrietta Leavitt's discovery important for star measurement?
Duplicate of and related to: astronomy.stackexchange.com/questions/3685/…; astronomy.stackexchange.com/questions/932/…; astronomy.stackexchange.com/questions/8037/…; astronomy.stackexchange.com/questions/1177/….
Mar
4
reviewed Edit Why are galaxies disk shaped?
Mar
4
revised Why are galaxies disk shaped?
(1) Changed L=mvr2 to L=mvr (see http://en.wikipedia.org/wiki/Angular_momentum) (2) "expects" --> "would expect" just to exceed 6 char minimum.
Mar
1
answered What are the cloud-like blobs in the Martian southern hemisphere?
Feb
15
awarded  Yearling
Feb
12
comment What astronomical observations would give conclusive proof of alien life?
@KeithThompson, I do. If you like, post more references, otherwise just don't. Your last comment is typical of snooty SE "I-am-the-best-you-are-the-last" people.