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

Undergrad Transformation matrix for an expanding space

  • johnconner
  • · Replies 54 ·
2
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54

Undergrad What is power suppression in CMB experiments?

  • windy miller
  • · Replies 4 ·
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4

Undergrad How Are Heavy Elements Distributed?

  • jeff davis
  • · Replies 12 ·
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12

Graduate Definition of the IAU for the ecliptic plane

  • member 672147
  • · Replies 2 ·
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2

High School Colliding Neutron Stars Collapse into Black Holes

  • lavinia
  • · Replies 2 ·
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2

Undergrad How do you calculate the cool-down rate of the Universe?

  • bbbl67
  • · Replies 7 ·
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7

The first British woman to space is a <can't say>

  • phinds
  • · Replies 14 ·
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14

Undergrad Some new evidence that the Dark Energy Concept is wrong

  • Buzz Bloom
  • · Replies 10 ·
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10

High School Can We Generate Detectable Gravitational Waves in a Lab?

  • Suppaman
  • · Replies 20 ·
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20

High School Debunking Dark Energy Theory: New Evidence Challenges Estimated Age of Universe

  • .Scott
  • · Replies 1 ·
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1

Graduate Why is there no distance-measure in the standard model?

  • Peter 727
  • · Replies 6 ·
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6

High School Matter falling into a black hole

  • MikeeMiracle
  • · Replies 8 ·
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8

Undergrad Matter movement versus spacetime expansion

  • Robin04
  • · Replies 3 ·
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3

Undergrad What causes the mysterious eclipses in Epsilon Aurigae?

  • zuz
  • · Replies 27 ·
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27

High School Questions about the cosmic microwave background radition and its discovery

  • PainterGuy
  • · Replies 4 ·
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4

Graduate Understanding Ohm and Hall Diffusion in Cosmic Rays

  • Pedro de la Torre
  • · Replies 1 ·
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1

Undergrad Help with the color of a star cluster

  • Astrofun42
  • · Replies 1 ·
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1

Undergrad What is the ultimate fate of the Universe?

  • curious222
  • · Replies 8 ·
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8

Undergrad Why do dark matter and baryon matter have different distributions?

  • Demystifier
  • · Replies 4 ·
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4

Undergrad Does gravity act differently on a Solar System, a Galasy, and the Universe?

  • KurtLudwig
  • · Replies 4 ·
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4

High School The observable and non-observable parts of the Universe

  • PainterGuy
  • · Replies 38 ·
2
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38

Graduate Three Body Problem - Statistical (almost) Solution

  • Tom.G
  • · Replies 2 ·
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2

Graduate Does Teleportation to Andromeda Equal Time Travel?

  • Maximum7
  • · Replies 2 ·
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2

High School Is Gravity Emergent? Answers to Pre-Big Bang Questions

  • wolram
  • · Replies 3 ·
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3

High School A second galaxy with no dark matter

  • wolram
  • · Replies 5 ·
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5

High School Who is Ethan Siegel and What Insights Does He Offer About the Universe?

  • curious222
  • · Replies 7 ·
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7

Graduate Computing sig8 for correction in non-linear regime

  • fab13
  • · Replies 2 ·
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2

Undergrad Calculating the Maximum total neutrino mass by using cosmological boun

  • Arman777
  • · Replies 6 ·
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6

Undergrad Questions on Galactic Coordinate Systems

  • KurtLudwig
  • · Replies 8 ·
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8

Stargazing Can I Use a DIY Hydrogen Alpha Solar Filter for Detailed Sun Photography?

  • Remedyworld
  • · Replies 11 ·
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11

Undergrad Can Flat Rotation Curves in Spiral Galaxies Be Explained by Dynamical Friction?

  • Ranku
  • · Replies 3 ·
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3

Undergrad Visibility of celestial bodies during the daytime

  • cptolemy
  • · Replies 22 ·
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22

Undergrad Is Minkowski spacetime a solution of the Friedmann Equations?

  • timmdeeg
  • · Replies 30 ·
2
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30

High School How did the universe come into being?

  • curious222
  • · Replies 3 ·
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3

High School Is this a star before it hit the ground on Earth?

  • MeteoriteChina
  • · Replies 14 ·
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14

High School See the first precise pulsar surface map

  • lomidrevo
  • · Replies 2 ·
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2

High School Dark Matter Distrbution in Galaxies

  • MikeeMiracle
  • · Replies 14 ·
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14

Undergrad Expansion of space & expansion of matter within space

  • artis
  • · Replies 17 ·
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17

High School Infinite Universes: The Science & Limits of the Theory

  • Redblue88
  • · Replies 11 ·
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11

Graduate Alfred Nobel Symposium 2005: Energy in Cosmos, Molecules and Life

  • Astronuc
  • · Replies 1 ·
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1

Undergrad Determining Degenerate Gas in Stellar Structure

  • Haynes Kwon
  • · Replies 1 ·
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1

High School New Storms on Jupiter, by Juno spacecraft

  • Tom.G
  • · Replies 1 ·
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1

Undergrad What is the role of voids in the Hubble tension?

  • Arman777
  • · Replies 11 ·
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11

Undergrad Is everything Lawrence Krauss said about the universe true?

  • curious222
  • · Replies 2 ·
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2

High School What factors influence the flattening of planets in our solar system?

  • JGHunter
  • · Replies 9 ·
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9

Undergrad Is This Newly Discovered Black Hole Breaking The Rules of Stellar-Mass Limit?

  • lomidrevo
  • · Replies 4 ·
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4

Undergrad Uncovering the Mystery: What Existed Before the Big Bang?

  • curious222
  • · Replies 12 ·
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12

High School Universe Discovery: The Finite Theory of the Big Bang and the End of the Cosmos

  • curious222
  • · Replies 1 ·
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1

Graduate Equation of state of gravitational energy in open de Sitter?

  • Vincentius
  • · Replies 6 ·
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6

Undergrad Absorption lines and emission lines in stellar spectra

  • Haynes Kwon
  • · Replies 3 ·
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3

High School Is the Universe's Expansion Misinterpreted Due to Curvature?

  • PK is a fool
  • · Replies 3 ·
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3

High School Cosmic Rays Charge: Expect Reissner-Nordstrom Black Holes?

  • William Nelso
  • · Replies 16 ·
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16

Undergrad Universe expansion discrepancy vs accelerated expansion

  • overzealous
  • · Replies 14 ·
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14

High School Shouldn't the time dilation in cosmic voids be immense?

  • staedtler
  • · Replies 15 ·
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15

High School What Insights Has Voyager 2 Provided From Interstellar Space?

  • wolram
  • · Replies 2 ·
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2

Undergrad How do we determine the ##H_0## from standard rulers and standard candle?

  • Arman777
  • · Replies 20 ·
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20

Undergrad Help with the Virial Theorem please

  • Alfie114
  • · Replies 4 ·
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4

Undergrad True length of sidereal year in 6000 b.c.e.

  • Edwin1974
  • · Replies 28 ·
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28

Undergrad First results from Parker Solar Probe on Wednesday (18:30 pm UTC)

  • mfb
  • · Replies 2 ·
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2

Undergrad Building a solar system simulator

  • Xilor
  • · Replies 15 ·
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15

High School Can Neutron Stars Lose Energy Through Radiation?

  • magneticanomaly
  • · Replies 10 ·
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10

Undergrad Which redshift value is used in the velocity measurement of distance

  • Arman777
  • · Replies 3 ·
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3

Undergrad Inside The 24/7 Search For Another Habitable Planet Within 100 Ly

  • alberto91
  • · Replies 10 ·
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10

Undergrad Formation of dark matter structures

  • andrew s 1905
  • · Replies 4 ·
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4

Undergrad Loop Quantum Cosmology: Explained in Layman's Terms

  • windy miller
  • · Replies 3 ·
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3

Undergrad Does Dark matter get trapped in black holes and increase their mass?

  • jms4
  • · Replies 14 ·
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14

Undergrad How did the initial dust particles form?

  • hwpage
  • · Replies 19 ·
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19

High School Why Jupiter, Saturn and the Sun have a distinctive and sharp boundary?

  • fbs7
  • · Replies 34 ·
2
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34

Undergrad Which instruments are used to determine the composition of dark matter?

  • Wentu
  • · Replies 3 ·
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3

High School How Did the Early Plasma in the Universe Become Hot?

  • wolram
  • · Replies 2 ·
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2

High School Molten Core of Mars: Could Tidal Action from a Moon Create a Magnetic Field?

  • Bill McKeeman
  • · Replies 18 ·
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18

Undergrad How do we know space is expanding?

  • Galactic explosion
  • · Replies 24 ·
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24

Undergrad What kind of information can we extract from this equation?

  • Arman777
  • · Replies 3 ·
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3

Undergrad Fulvio Melia's new argument for a linear cosmology

  • jcap
  • · Replies 11 ·
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11

High School Simulation of a Galaxy, most detailed large-scale simulation to date

  • Spinnor
  • · Replies 1 ·
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1

High School Are supernovas more likely to produce neutron stars or black holes?

  • Moon Shine
  • · Replies 7 ·
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7

Undergrad The Supergalactic plane and a coordinate system

  • darkdave3000
  • · Replies 15 ·
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15

Undergrad Dark Matter Mass: Evidence of Low-Mass?

  • Ranku
  • · Replies 7 ·
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7

Undergrad How Far Can the Square Kilometre Array 'Listen' for Extraterrestrial Signals?

  • alberto91
  • · Replies 22 ·
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22

High School Lithium problem in Big Bang nucleosynthesis?

  • Aidyan
  • · Replies 2 ·
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2

Undergrad Neutron Star Core: Empty Obloid Cavity & Exotic Content?

  • Srb2001
  • · Replies 9 ·
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9

Graduate SPACE ROCKS: Latest meteorite into my collection

  • davenn
  • · Replies 3 ·
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3

High School Meteor Storm Possible Thursday Night November 21-22

  • websterling
  • · Replies 5 ·
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5

Graduate In the power spectrum, why is the peak frequency at the first harmonic

  • dave gannon
  • · Replies 5 ·
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5

Undergrad Help With Simple Orbital Modeling

  • Gumbrain
  • · Replies 4 ·
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4

Graduate Steps on the way to Lightcone cosmological calculator

  • marcus
  • · Replies 86 ·
3
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86

High School Why do we assume the big bang created matter/antimatter?

  • physical
  • · Replies 2 ·
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2

Undergrad Can S5-HVS1 Retain Its Planets?

  • DavidCummings
  • · Replies 2 ·
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2

Undergrad Clarifying the Meaning of Radius of Curvature in Cosmology

  • Arman777
  • · Replies 13 ·
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13

Undergrad New measurement of the Hubble constant is consistent with the CMB value

  • phyzguy
  • · Replies 10 ·
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10

Graduate Calculating the Gravitational wave spectrum with Inflation as a source

  • shinobi20
  • · Replies 3 ·
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3

Graduate Missing step in the derivation of the Robertson-Walker metric

  • Roy_1981
  • · Replies 31 ·
2
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31

Undergrad Why is there a difference between the composition of planets and stars?

  • artis
  • · Replies 28 ·
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28

High School How constrained are the initial conditions of the universe?

  • Quantum Alchemy
  • · Replies 1 ·
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1

High School Water found on potentially habitable exoplanet

  • phinds
  • · Replies 8 ·
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8

Stargazing Witness the Transit of Mercury: Nov 11, 2019

  • Andy Resnick
  • · Replies 13 ·
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13

Undergrad Cuspy Halo Problem: Questions & Answers

  • Arman777
  • · Replies 5 ·
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5

High School Will Big Stars Turn Into Red Supergiants or Red Giants?

  • Odette
  • · Replies 5 ·
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5

High School If I were to observe a black hole....

  • PG1
  • · Replies 19 ·
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19

Undergrad Angular Momentum in a Solar Nebula

  • Comeback City
  • · Replies 7 ·
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7