Astronomy, Astrophysics, Cosmology Forum

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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.
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Our Beautiful Universe - Photos and Videos
  • DennisN
  • · Replies 2K ·
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Stargazing How Can You Improve Your Amateur Solar Imaging Techniques?
  • davenn
  • · Replies 311 ·
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311
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Insights Equations of State for Photon Gas and Relativistic Electron Gas
  • andrewkirk
  • · Replies 0 ·
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0
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Graduate Astronomy and Cosmology FAQ List
  • Greg Bernhardt
  • · Replies 3 ·
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Undergrad Does the steady-state model resolve Olbers' paradox?
  • Jaime Rudas
  • · Replies 61 ·
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Undergrad Theta Eridani was much brighter for early astronomers
  • mfb
  • · Replies 1 ·
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High School Good drawing of Earth's orbit for model? Possibly vector file?
  • LightningInAJar
  • · Replies 38 ·
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Undergrad Intelligent life and the Fermi Paradox
  • Jupiter60
  • · Replies 9 ·
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9
Undergrad "Scientists have measured space to be flat to high accuracy"
  • sevensages
  • · Replies 12 ·
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12
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
Stargazing Solar Activity and Space Weather Update thread
  • Stavros Kiri
  • · Replies 464 ·
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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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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 ·
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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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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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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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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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High School Size of the early universe as we see now
  • stuart100
  • · Replies 1 ·
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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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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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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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Undergrad M31-2014-DS1, slow disappearance of a massive star
  • Astronuc
  • · Replies 1 ·
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High School A Mind-Boggling Number Comparison
  • peanutaxis
  • · Replies 54 ·
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Undergrad Abundant water from primordial supernovae at cosmic dawn
  • Astronuc
  • · Replies 1 ·
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Undergrad Exoplanet, HD 137010 b and it's star, HD 137010
  • Astronuc
  • · Replies 0 ·
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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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Graduate Larson-Sekanina Rotational Gradient Filter for comet 3i/Atlas
  • Julian_M
  • · Replies 0 ·
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Undergrad Milne vs. Minkowski metric
  • PAllen
  • · Replies 30 ·
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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 ·
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Undergrad Blueshift in case of the Big Crunch scenario
  • hedgehug
  • · Replies 9 ·
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Undergrad Are Boltzmann brains predicted by our current cosmological theories?
  • grassyourhorse
  • · Replies 12 ·
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Undergrad Unexpected findings in need of an explanation (retrograde motion of Mars)
  • Sylvain9595
  • · Replies 83 ·
3
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Undergrad Rotation curve in spiral galaxy velocity and uniform velocity dispersion
  • Ranku
  • · Replies 4 ·
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High School Contradictions in the Distribution of Gamma-Ray Bursts
  • Line_112
  • · Replies 24 ·
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High School Expansion and raisin bread
  • John Helly
  • · Replies 5 ·
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High School Questions about the structure of dark matter
  • untilthecern
  • · Replies 4 ·
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Undergrad Merely a thought of where the universe expands into
  • Dominion
  • · Replies 2 ·
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Undergrad Galaxy MoM-z14 - furthest observed object
  • Astronuc
  • · Replies 9 ·
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High School Estimates — True Size of the Universe?
  • Ascendant0
  • · Replies 33 ·
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Undergrad How our Moon and Sun may affect Earth's equatorial bulge
  • lunatectonics
  • · Replies 3 ·
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Undergrad Luminous Fast Blue Optical Transients (LFBOTs)
  • Astronuc
  • · Replies 0 ·
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Undergrad Before the Big Bang
  • Jaime Rudas
  • · Replies 31 ·
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Undergrad Galactic collision and dark matter
  • Skaperen
  • · Replies 1 ·
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High School Is it a meteor or a meteorite when it makes moonfall?
  • DaveC426913
  • · Replies 3 ·
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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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High School Is this a coincidence?... (distances between planets)
  • Jan Naus
  • · Replies 7 ·
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High School NASA Data Site Down
  • LightningInAJar
  • · Replies 5 ·
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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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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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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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Rock on Mars possibly indicating Life
  • BillTre
  • · Replies 14 ·
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High School If the Universe has a cause, what caused that cause?
  • sahana
  • · Replies 13 ·
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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 ·
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High School Star like object travels in a zigzagging pattern relative to other stars
  • lbiskupec
  • · Replies 49 ·
2
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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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Undergrad Questions about quantum cosmology
  • kodama
  • · Replies 8 ·
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8
Undergrad Where did the early photons go?
  • John Helly
  • · Replies 34 ·
2
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High School Can big bang be a part of a loop?
  • anuureeett
  • · Replies 2 ·
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2