Hottest Questions This Month

30 votes

1 answer

5k views

Trying to identify something I saw in the sky

meteor

OrOrg

596

modified Jun 22 at 10:23

27 votes

1 answer

5k views

Why is the summer solstice night shorter than the winter solstice day?

Glorfindel

4,605

modified Jun 14 at 19:55

13 votes

2 answers

4k views

Why are asteroids so much richer in precious metals than Earth's crust?

asteroids

Emilio M Bumachar

141

answered Jun 10 at 18:30

8 votes

3 answers

2k views

Planets looks like normal stars when I see them using telescope

planet telescope amateur-observing jupiter saturn

EggsundHam

31

answered Jun 13 at 2:32

10 votes

2 answers

1k views

JPL Horizons - "highly accurate measurements of planetary positions" - how do they do it?

positional-astronomy ephemeris

uhoh

31.5k

modified Jun 26 at 19:01

19 votes

1 answer

3k views

Has the small meteorite that hit Webb done a lot of damage?

meteorite james-webb-space-telescope

David Hammen

28.1k

modified Jun 11 at 11:38

6 votes

1 answer

1k views

Finding Scorpio in the Milky Way panorama

photography milky-way

James K

88.7k

modified Jun 5 at 18:01

7 votes

3 answers

662 views

How can I calculate an orbital elliptic trajectory from the velocity vector?

orbit astrophysics

Willyam Carkey

89

modified Jun 26 at 21:35

4 votes

1 answer

2k views

What does "to within less than about thirty Schwarzschild radii" mean?

black-hole astrophysics

ProfRob

115k

answered Jun 27 at 7:16

4 votes

1 answer

2k views

How sure are we about the speed of light in vacuum in deep/far space?

hubble-constant

ProfRob

115k

answered Jun 15 at 16:30

11 votes

1 answer

1k views

What are those stars that cross the galactic center?

star galaxy milky-way

Pierre Paquette

4,272

modified Jun 9 at 1:21

9 votes

1 answer

546 views

What does "Effective radius of [CII] line is 1.4 kpc" mean?

spectroscopy quasars

pela

32.3k

modified Jun 16 at 16:21

8 votes

1 answer

824 views

Binoculars 10x50 in light polluted place

planet amateur-observing deep-sky-observing light-pollution binoculars

JayFor

126

answered Jun 28 at 18:47

11 votes

1 answer

788 views

Early Milky Way depictions after Herschel?

milky-way history

M. A. Golding

4,845

modified Jun 23 at 21:05

9 votes

1 answer

514 views

What unit of year in JPL Small-Body Database Lookup?

ephemeris definition

notovny

3,115

answered Jun 13 at 9:49

5 votes

2 answers

838 views

What does "by an amount" mean here?

astrophysics

Martin Kealey

101

modified 21 hours ago

7 votes

3 answers

201 views

escape velocity of leaving the Milky Way galaxy vertically and horizontally

escape-velocity

Connor Garcia♦

13.8k

answered Jun 22 at 21:30

3 votes

2 answers

473 views

Is this scaling of JWST halo reasonably correct

orbit james-webb-space-telescope visualization

PM 2Ring

9,379

modified Jun 19 at 11:00

4 votes

1 answer

330 views

What does using these units (c=G=M=1) in MHD simulations mean?

accretion-discs units

ProfRob

115k

modified Jun 26 at 6:52

4 votes

1 answer

362 views

Virial theorem, contraction, and stars getting hotter

stellar-evolution hydrostatic-equilibrium

ProfRob

115k

answered Jun 26 at 18:19

5 votes

1 answer

193 views

Reason for different surface temperatures of Tau Ceti and Epsilon Indi at similar properties

star temperature spectral-type

Rob

1,251

answered Jun 28 at 12:47

5 votes

1 answer

154 views

How many stars can we resolve?

star galaxy gaia

ksousa

782

modified Jun 11 at 22:56

-2 votes

1 answer

114 views

Wouldn't the 1054 supernova have temporarily enlightened the Earth like the Sun?

the-sun supernova nebula

uhoh

31.5k

modified Jun 12 at 1:44

3 votes

1 answer

197 views

When exactly was the last time that Earth's aphelion coincided (within 24 hours) with the northern winter (December) solstice?

orbit precession solstice

PM 2Ring

9,379

modified 53 mins ago

2 votes

2 answers

119 views

Measuring distance to stars - How to get parallax angle

amateur-observing parallax

James K

88.7k

answered Jun 8 at 18:25

1 vote

1 answer

141 views

Should we fear Wolf-Rayet WR-104?

supernova gamma-ray-bursts wolf-rayet

David Hammen

28.1k

answered Jun 24 at 14:05

1 vote

1 answer

83 views

following several unknown phenomena detected at the edge of the solar system, is there a 5th force which acts at the edge of the solar system?

observational-astronomy astrophysics cosmology asteroids

James K

88.7k

answered Jun 25 at 11:11

6 votes

2 answers

72 views

In terms of results, how similar is a bunch of telescopes across the globe to an Earth-sized telescope?

observational-astronomy radio-astronomy radio-telescope interferometry event-horizon-telescope

Carl Witthoft

3,578

answered Jun 10 at 12:51

1 vote

1 answer

128 views

Distribution function for distance to nearest stars from any given star in our galaxy

galaxy distances

Anders Sandberg

10.3k

modified Jun 7 at 8:42

2 votes

2 answers

69 views

How to find the first Julian day with the same Earth-Sun constellation

algorithm sunrise sunset

Eric Jensen

4,259

answered Jun 5 at 13:57

0 votes

1 answer

68 views

Do we get shortest shadow of any object at Solstice time or Meridian time?

the-sun solstice

James K

88.7k

modified Jun 21 at 19:10

4 votes

1 answer

83 views

Stellar evolution temperature gradient - why the logarithm?

star stellar-evolution stellar-astrophysics

pela

32.3k

modified 2 days ago

3 votes

1 answer

79 views

Is V616 Monocerotis the closest black hole?

black-hole distances

James K

88.7k

answered Jun 5 at 22:38

4 votes

1 answer

60 views

What does it mean that the radial coordinate becomes the time coordinate behind the horizon?

black-hole hawking-radiation

ProfRob

115k

answered Jun 13 at 18:05

2 votes

2 answers

98 views

What is stopping Event Horizon Telescope the size of the Earth’s orbit?

telescope space-telescope interferometry event-horizon-telescope

Rob

1,251

answered 2 days ago

-1 votes

1 answer

75 views

How to calculate metallicity of a star that is made of iron of 20kg and Hydrogen 1000 kg?

star mass metallicity

planetmaker

11k

modified Jun 13 at 15:26

5 votes

1 answer

58 views

What kinds of stars have viable habitable zones other than G-type stars, and what would life be like orbiting them?

star planet habitable-zone dwarf-star

M. A. Golding

4,845

answered 2 days ago

3 votes

1 answer

92 views

Does "Angular Diameter Turnaround Point" solve the Great Wall Problem?

observational-astronomy observable-universe size age

pela

32.3k

answered Jun 23 at 12:39

1 vote

2 answers

86 views

Could primordial black holes explain the SMBH in the galactic centers?

black-hole dark-matter supermassive-black-hole galactic-dynamics

ProfRob

115k

answered Jun 20 at 16:20

3 votes

1 answer

60 views

Is the dark matter/baryonic matter ratio the same in galaxies with supermassive black holes?

gravity dark-matter supermassive-black-hole dark-energy

pela

32.3k

modified Jun 13 at 13:42

3 votes

1 answer

57 views

How can the upper limit for a star's mass be calculated?

star mass eddington-luminosity

ProfRob

115k

modified Jun 22 at 16:39

2 votes

1 answer

71 views

Celestial coordinates of every pixel in the image

coordinate astrometry

Peter Erwin

14.7k

answered Jun 16 at 12:35

0 votes

1 answer

91 views

What's the proper shape of a black hole?

black-hole

Anders Sandberg

10.3k

answered Jun 19 at 16:50

2 votes

1 answer

67 views

What exactly causes "color twinkling" and why does it seem that any color might be furthest refracted for a moment?

observational-astronomy amateur-observing atmospheric-effects

Greg Miller

1,139

answered Jun 4 at 17:10

1 vote

1 answer

58 views

redshift puzzle

observational-astronomy galaxy redshift

ProfRob

115k

modified Jun 15 at 9:43

2 votes

1 answer

58 views

What criteria determines whether stars are supernova type II candidates?

supernova gaia red-supergiant

ProfRob

115k

modified Jun 27 at 14:19

7 votes

0 answers

91 views

How are the occurrence and nature of micrometeoroid impacts on JWST optics identified?

space-telescope james-webb-space-telescope mirror meteoroid space-debris

Roger Wood

1,194

modified Jun 17 at 15:15

2 votes

0 answers

114 views

Order of magnitude of this phase space invariant?

general-relativity

omivela17

1

modified Jun 9 at 15:29

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