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Top Questions

18 votes
3 answers
6k views

Why don't they put more spare gyroscopes in expensive space telescopes?

15 votes
3 answers
5k views

Why is Uranus colder than Neptune?

7 votes
4 answers
5k views

Are the North Star and the moon ever visible in the night sky at the same time?

14 votes
2 answers
4k views

Are there really half-a billion visible supernovae exploding all the time?

4 votes
2 answers
2k views

Can a star be made of sun spots?

6 votes
2 answers
2k views

Why does c show up in Schwarzschild's equation for the horizon radius?

9 votes
2 answers
1k views

In the onion-like elemental layers of a large mature star the neon is closer to the surface than oxygen, even though it is more massive... Why?

5 votes
4 answers
2k views

Could two moons orbit each other around a planet?

10 votes
1 answer
945 views

Are any Population III stars red dwarfs?

4 votes
1 answer
580 views

Finding a paper that has only abstract on ADS

4 votes
1 answer
1k views

How close would a quasar have to be to be seen with the naked eye?

2 votes
1 answer
344 views

What is the best catalog of black hole candidates?

4 votes
1 answer
304 views

How will a planet on asteroid belt see Jupiter?

0 votes
1 answer
140 views

If the lunar maria are impact craters, why don't they have central peaks?

3 votes
3 answers
217 views

Why don’t runaway stars happen more often?

1 vote
2 answers
143 views

Can we detect gravitational waves from galaxies merging?

1 vote
1 answer
241 views

Is this a galaxy?

3 votes
0 answers
422 views

Are there any video/audio recordings of the launch of sputnik 1? [migrated]

-2 votes
2 answers
93 views

What is _now_ on planet in another galaxy?

0 votes
1 answer
150 views

Someone explain how a naked singularity is possible

-1 votes
1 answer
147 views

Does a football field size asteroid really fall past the moon once a week?

2 votes
1 answer
180 views

Last Thursday's mile-wide asteroid that missed: what angle would it have hit?

-1 votes
1 answer
268 views

Inconsistency between Velocity vs Redshift and Scale Factor vs Time plots

2 votes
1 answer
96 views

What exactly does $k\sigma$ mean in astrophysics and cosmology?

3 votes
2 answers
118 views

Why don't stars 0.5<m<0.8 solar masses undergo a helium flash?

-2 votes
2 answers
107 views

What is the nature of magnetism within and without the Galatic plane?

1 vote
1 answer
82 views

What is the relationship between core temperature and surface temperature in main-sequence stars?

2 votes
2 answers
78 views

Mathematical modeling of the influence of components of the interstellar medium on the distortion of the wavefront of the observed object

3 votes
1 answer
75 views

Pyephem equivalent when living on Mars?

2 votes
1 answer
118 views

Why do so many moons in the solar system orbit retrograde?

2 votes
0 answers
144 views

Light flashes in night sky with a ~14 second period?

3 votes
1 answer
68 views

What is DESI's spatial resolution?

4 votes
1 answer
87 views

How could a new cosmological model solve the hubble tension?

0 votes
1 answer
66 views

Using SExtractor for JWST data

0 votes
0 answers
102 views

The Julian Day Bug

0 votes
1 answer
59 views

What's the name of the projection onto the celestial sphere of the tropic of cancer?

2 votes
1 answer
74 views

Request for Information on how to make a FITS Image

1 vote
0 answers
78 views

Metallicity of Celestial Objects: Why "Metal = Non-metal" Source

0 votes
1 answer
72 views

Moon's ecliptic latitude and longitude [duplicate]

2 votes
1 answer
55 views

How can a planet's perihelion be raised during migration?

3 votes
0 answers
70 views

How to find the minimum range at which some imaging payload/instrument can produce a clear image?

0 votes
0 answers
69 views

How does one determine the cardinal direction in which analemma was photographed?

2 votes
0 answers
65 views

Using prospector for jwst data

1 vote
0 answers
63 views

Help me figure out how to solve the gravitational lens equations

2 votes
1 answer
59 views

Why does the blue loop occur?

0 votes
0 answers
58 views

How soon after the accretion did Mars experience the magma-ocean stage?

2 votes
1 answer
43 views

Why would some sources in a cross-matched DESI/SDSS catalog have different spectroscopic redshifts?


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