Astronomy, Astrophysics, Cosmology Forum

Join in expert discussion on the topics of Astronomy, astrophysics and cosmology. This may include discussion on celestial objects, space, and the physical universe as a whole. Mainstream science only.

Threads

  • Sticky

Our Beautiful Universe - Photos and Videos

  • DennisN
  • · Replies 2K ·
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  • Sticky

Graduate Astronomy and Cosmology FAQ List

  • Greg Bernhardt
  • · Replies 3 ·
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3

Undergrad "Scientists have measured space to be flat to high accuracy"

  • sevensages
  • · Replies 13 ·
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13

Stargazing Solar Activity and Space Weather Update thread

  • Stavros Kiri
  • · Replies 466 ·
16
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466

Thought Experiment: What Lies Beyond the Furthest Object in Space?

  • Amazed
  • · Replies 11 ·
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11

High School What if we could use a Black Hole as starship?

  • Fabien
  • · Replies 17 ·
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17

Undergrad Does the steady-state model resolve Olbers' paradox?

  • Jaime Rudas
  • · Replies 61 ·
3
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61

Undergrad Theta Eridani was much brighter for early astronomers

  • mfb
  • · Replies 1 ·
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1

High School Good drawing of Earth's orbit for model? Possibly vector file?

  • LightningInAJar
  • · Replies 38 ·
2
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38

Undergrad Intelligent life and the Fermi Paradox

  • Jupiter60
  • · Replies 9 ·
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9

High School Long rod in orbit

  • GTOM
  • · Replies 21 ·
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21

High School Help with the protocol for accurately recording an orbit for the IAU

  • Celesty
  • · Replies 3 ·
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3

The James Webb Space Telescope

  • valenumr
  • · Replies 545 ·
19
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545

High School Will we ever communicate with extraterrestial life in a reasonable time frame?

  • Frimus
  • · Replies 3 ·
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3

High School Spotting 1997 NC1 flyby on Fri/Sat

  • DaveC426913
  • · Replies 2 ·
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2

High School 3I/ATLAS, Interstellar Comet

  • Astronuc
  • · Replies 22 ·
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22

Undergrad Hubble Constant, Dark Energy and the Expanding Universe

  • PhanthomJay
  • · Replies 22 ·
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22

Undergrad Cosmological Redshift and Expansion

  • Jaime Rudas
  • · Replies 51 ·
2
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51

High School Dark energy might not be constant after all

  • Filip Larsen
  • · Replies 12 ·
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12

High School Anyone come across this new YouTube channel?

  • pbuk
  • · Replies 19 ·
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19

What is the word for the momentum of the Earth orbiting the Sun?

  • sevensages
  • · Replies 3 ·
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3

High School Formation of gravastars

  • Sagittarius A-Star
  • · Replies 9 ·
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9

Graduate Could the Foucault precession be an incomplete forcing?

  • Simon F
  • · Replies 2 ·
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2

Do you 'see' the CMB map as a 3D glass sphere/ellipsoid?

  • Roberto Pavani
  • · Replies 1 ·
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1

High School The One Electron Universe suggested by Wheeler

  • Parthib Roy
  • · Replies 10 ·
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10

High School A question on the geometry of black holes

  • Parthib Roy
  • · Replies 57 ·
2
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57

High School Near-Earth Object/Asteroid 2026 JH2

  • Astronuc
  • · Replies 2 ·
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2

The Universe’s Brightest Explosions Were Discovered by Accident

  • spacestorm
  • · Replies 2 ·
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2

High School Can a black hole become a white hole?

  • member 775858
  • · Replies 7 ·
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7

High School GRB 250702B, the longest gamma-ray burst in history

  • Astronuc
  • · Replies 6 ·
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6

High School Could the interstellar medium distort alien signals?

  • Line_112
  • · Replies 2 ·
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2

Stargazing TRAPPIST-1 system

  • hmrgee
  • · Replies 1 ·
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1

Undergrad Practical cosmic speed limit for macroscopic objects?

  • BWV
  • · Replies 15 ·
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15

Undergrad Are Alternative Dark Energy Models Treated More Favorably Than MOND?

  • BWV
  • · Replies 13 ·
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13

Undergrad Dumb Dumb has a question (standard candles)

  • Murphy625
  • · Replies 3 ·
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3

Undergrad Ice on the moon

  • thetexan
  • · Replies 10 ·
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10

Undergrad Does Spacetime rotate like a vortex?

  • james_bellhouse
  • · Replies 6 ·
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6

High School Theory on universe expansion

  • JackFmultiverse
  • · Replies 4 ·
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4

Undergrad Help Understanding the Hubble Constant's Units

  • skynr13
  • · Replies 22 ·
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22

High School Deflection of Light by the Sun

  • nanjo
  • · Replies 3 ·
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3

Stargazing Astronomy: Orbit Terminology

  • Pixelworks
  • · Replies 41 ·
2
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41

High School Size of the early universe as we see now

  • stuart100
  • · Replies 1 ·
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1

Undergrad Live data from Artemis 2?

  • LightningInAJar
  • · Replies 6 ·
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6

Undergrad Is our definition of 'cosmic voids' misleading the H₀ discussion?

  • qql504
  • · Replies 1 ·
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1

Undergrad Large Synoptic Survey Telescope -> Vera C. Rubin Observatory

  • mfb
  • · Replies 15 ·
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15

High School Infinite universe, infinite volume from the beginning?

  • mister i
  • · Replies 22 ·
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22

Stargazing Meteor/meteorite made a big boom this morning!

  • Andy Resnick
  • · Replies 19 ·
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19

High School ASASSN-15lh (aka SN 2015L), a superluminal supernova, or hypernova?

  • Astronuc
  • · Replies 9 ·
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9

High School Uracil found in carbonaceous asteroid

  • BWV
  • · Replies 10 ·
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10

High School Independent Inflationary Regions in an Infinite Universe?

  • mister i
  • · Replies 28 ·
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28

Graduate Why are the bulge particles coming out in the Gadget 2 simulation?

  • bijuastro
  • · Replies 2 ·
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2

Undergrad Age of the Universe and the Cosmological Constant

  • Ranku
  • · Replies 18 ·
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18

Undergrad A paper regarding the Hubble tension using Gaia data

  • pinball1970
  • · Replies 3 ·
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3

Undergrad What part of Mars Rover or Mars satellite has this cone object fallen from?

  • Julian_M
  • · Replies 10 ·
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10

Undergrad M31-2014-DS1, slow disappearance of a massive star

  • Astronuc
  • · Replies 1 ·
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1

High School A Mind-Boggling Number Comparison

  • peanutaxis
  • · Replies 54 ·
2
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54

Undergrad Abundant water from primordial supernovae at cosmic dawn

  • Astronuc
  • · Replies 1 ·
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1

Undergrad Exoplanet, HD 137010 b and it's star, HD 137010

  • Astronuc
  • · Replies 0 ·
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0

Undergrad Question of accuracy of galactic collision simulations

  • Halc
  • · Replies 11 ·
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11

Graduate Project Progress Report and possible Radio Astronomy Technique?

  • Paul Colby
  • · Replies 9 ·
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9

High School What is space?

  • stephen h
  • · Replies 13 ·
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13

Undergrad Is Vacuum Decay from a False to True State Impossible or Just Unlikely?

  • Suekdccia
  • · Replies 3 ·
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3

Graduate Larson-Sekanina Rotational Gradient Filter for comet 3i/Atlas

  • Julian_M
  • · Replies 0 ·
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0

Undergrad Milne vs. Minkowski metric

  • PAllen
  • · Replies 30 ·
2
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30

Undergrad Comparing different scale factor functions in the same graph

  • hedgehug
  • · Replies 6 ·
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6

Undergrad Does the scale factor need to be normalized?

  • hedgehug
  • · Replies 93 ·
4
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93

Undergrad Blueshift in case of the Big Crunch scenario

  • hedgehug
  • · Replies 9 ·
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9

Undergrad Are Boltzmann brains predicted by our current cosmological theories?

  • grassyourhorse
  • · Replies 12 ·
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12

Undergrad Unexpected findings in need of an explanation (retrograde motion of Mars)

  • Sylvain9595
  • · Replies 83 ·
3
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83

Undergrad Rotation curve in spiral galaxy velocity and uniform velocity dispersion

  • Ranku
  • · Replies 4 ·
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4

High School Contradictions in the Distribution of Gamma-Ray Bursts

  • Line_112
  • · Replies 24 ·
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24

High School Expansion and raisin bread

  • John Helly
  • · Replies 5 ·
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5

High School Questions about the structure of dark matter

  • untilthecern
  • · Replies 4 ·
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4

Undergrad Merely a thought of where the universe expands into

  • Dominion
  • · Replies 2 ·
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2

Undergrad Galaxy MoM-z14 - furthest observed object

  • Astronuc
  • · Replies 9 ·
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9

High School Estimates — True Size of the Universe?

  • Ascendant0
  • · Replies 33 ·
2
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33

Undergrad How our Moon and Sun may affect Earth's equatorial bulge

  • lunatectonics
  • · Replies 3 ·
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3

Undergrad Luminous Fast Blue Optical Transients (LFBOTs)

  • Astronuc
  • · Replies 0 ·
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0

Undergrad Before the Big Bang

  • Jaime Rudas
  • · Replies 31 ·
2
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31

Undergrad Galactic collision and dark matter

  • Skaperen
  • · Replies 1 ·
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1

High School Is it a meteor or a meteorite when it makes moonfall?

  • DaveC426913
  • · Replies 3 ·
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3

High School Lunar Orbit Issues & Lunar Clocks

  • Jaziel
  • · Replies 4 ·
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4

Undergrad Do existing EFE solutions support Closed Timelike Curves?

  • cianfa72
  • · Replies 7 ·
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7

High School Is this a coincidence?... (distances between planets)

  • Jan Naus
  • · Replies 7 ·
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7

High School NASA Data Site Down

  • LightningInAJar
  • · Replies 5 ·
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5

High School Looking for info about the Sombrero Galaxy

  • mayflowers
  • · Replies 10 ·
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10

Undergrad Could Venus be a 'Soot World'?

  • Al_
  • · Replies 14 ·
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14

High School Gravitational effects of a small black hole passing your body

  • fresh_42
  • · Replies 1 ·
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1

Undergrad The quintessence as variable dark energy

  • Jaime Rudas
  • · Replies 18 ·
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18

Graduate Couldn't the cosmological constant also have some sort of "dynamics"?

  • mad mathematician
  • · Replies 4 ·
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4

Undergrad Is there anything inside a black hole?

  • Green dwarf
  • · Replies 16 ·
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16

High School Red shifted tired light doubts

  • MikeG
  • · Replies 10 ·
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10

Undergrad Population 3 star (Pop III) candidate LAP1

  • pinball1970
  • · Replies 3 ·
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3

Graduate Strong Progenitor Age Bias in Supernova Cosmology

  • PeterDonis
  • · Replies 30 ·
2
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30

Rock on Mars possibly indicating Life

  • BillTre
  • · Replies 14 ·
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14

High School If the Universe has a cause, what caused that cause?

  • sahana
  • · Replies 13 ·
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13

High School Looking to get a better understanding of bubble universe formation

  • Lynch101
  • · Replies 3 ·
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3

High School Is space stretching or is new space being created?

  • revnice
  • · Replies 47 ·
2
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47

High School Star like object travels in a zigzagging pattern relative to other stars

  • lbiskupec
  • · Replies 49 ·
2
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49

Undergrad Visible light Over Large Distances

  • RobbyQ
  • · Replies 4 ·
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4

High School Rutgers finds a transparent Einstein Cross - apparently a dark matter "halo"

  • .Scott
  • · Replies 8 ·
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8

Undergrad Questions about quantum cosmology

  • kodama
  • · Replies 8 ·
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8