All Questions
9 questions
3
votes
1
answer
67
views
Is it possible to detect lyman alpha blobs (LABs) with the lyman-break method?
LABs are luminous extended nebulae of hydrogen gas in the early universe (z ≥ 3) found in overdensities of LAEs (lyman-alpha emitters) and LBGs (lyman-break galaxies). I was wondering if LABs could be ...
- 61
0
votes
1
answer
780
views
Can you calculate the radius of a galaxy from Angular Size?
Is there a formula for calculating the size of a galaxy or even a nebula if you have the Angular Size. For example, M31 has an angular size of 199.53 70.79 35 (Opt) D
M31 should be 200,000 light ...
- 1,341
3
votes
1
answer
300
views
Can violet astronomical objects exist?
According to black-body radiation, violet stars are not possible.
Even if there are 1 million Kelvin, they are blue, not violet. But are violet galaxies, nebulae, clusters etc. possible?
Google found ...
- 31
3
votes
1
answer
220
views
Are the bright dots in this image individual stars?
I saw this picture of M51 (Whirlpool galaxy) and noticed many, many bright dots around and in the galaxy. I have freehand-circled a few as examples. Are these individual stars (probably supergiants) ...
1
vote
2
answers
1k
views
Is this an actual nebula or CGI?
I'm thinking of putting a large wall paper with an astronomical motive on a wall. I found quite a number of wall papers by various vendors, but most of them are obviously computer generated images, ...
- 769
0
votes
1
answer
954
views
Is the galaxy made of a nebula or the solar system?
My book says on the topic 'Formation of stars' that a galaxy starts forming by the accumulation of hydrogen gas in the form of very large clouds called nebulae. Then local lumps of gas are formed. ...
- 191
3
votes
2
answers
304
views
How do I see more than just points in the sky?
I just bought a new telescope with these specifications:
Aperture: 203 mm
Focal Length: 1200 mm
F/ratio: f/5.9
I usually use a 28 mm eyepiece, giving me about 42.5x magnification, but I also have a ...
4
votes
2
answers
580
views
How to tell a nebula from a galaxy?
Not all galaxies are spiral in shape[1][2], some nebulae are huge[3] and nebula are the nursery of stars[4]. How to tell them apart?
Note
I have already compare the contents for galaxy and a nebula, ...
- 2,511
31
votes
2
answers
38k
views
How many stars and galaxies can be seen by the naked eye?
How many of the luminous dots that we see naked are galaxies and not stars from our galaxy?
I imagine that the majority of the luminous points that we see naked eye during the night, are actually ...
- 617