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
High School What Are Quasi-Moons and How Do They Orbit Earth and the Sun?
- Hornbein
- · Replies 0 ·
Undergrad Simplifying standard error formula for redshift
- Rageuke
- · Replies 3 ·
Stargazing 'Devil' comet visible tonight 21.04.24
- pinball1970
- · Replies 8 ·
High School How Do Radars in Space Prevent Signal Dispersion and Maintain Target Accuracy?
- Field physics
- · Replies 10 ·
Stargazing What Could This Unidentified Moving Object in My Seestar S50 Sky Capture Be?
- Skywave
- · Replies 10 ·
Undergrad Did the big bang start from a single point or could it have been uneven?
- JuneSpring25
- · Replies 13 ·
Undergrad Questions about the accelerating Hubble expansion
- Kairos
- · Replies 36 ·
Undergrad Sun shade on Earth ground, is it a straight line or a curved line?
- applied-physics
- · Replies 3 ·
Undergrad Orientation of the Earth, Sun and Solar System in the Milky Way
- fizixfan
- · Replies 142 ·
Undergrad The linear polarization and brightness of pulsars
- ZX.Liang
- · Replies 0 ·
High School Recommendations for International Research Competitions
- Andrii Dzygunenko
- · Replies 4 ·
Undergrad Where Are the Missing Black Holes in the Milky Way?
- Vanadium 50
- · Replies 87 ·
High School How to use the Binary Mass Function for exoplanets?
- Astroxzip
- · Replies 4 ·
Undergrad Has JWST solved the crisis in cosmology?
- MrRobotoToo
- · Replies 2 ·
Undergrad How fast were distant galaxies moving?
- kymner
- · Replies 7 ·
Undergrad Inflationary vs deflationary phase of Big Bang
- BIGphysician
- · Replies 10 ·
Undergrad Meaning of the distance between galactic objects in GR
- cianfa72
- · Replies 9 ·
Undergrad Speed of the umbra during eclipse vs rate of the Earth's rotation
- imsmooth
- · Replies 3 ·
High School What is the actual shape of black holes?
- souriyas
- · Replies 4 ·
Undergrad Increase frequency of solar eclipses
- LightningInAJar
- · Replies 6 ·
High School Matter-antimatter asymmetry - a simple explanation?
- JoaLi
- · Replies 12 ·
High School Things to try while watching the solar eclipse
- jedishrfu
- · Replies 48 ·
Undergrad Expanding Universe without dark energy
- takacszoltan87
- · Replies 3 ·
Undergrad Can there be slowly-falling accretion disks in black holes?
- Suekdccia
- · Replies 11 ·
High School How black hole Sgr-A* Was Found
- jedishrfu
- · Replies 1 ·
Undergrad Is there an equivalent "redshift" for cosmic rays due to expansion?
- Suekdccia
- · Replies 14 ·
Undergrad The Evolution of Galactic Scale Cosmic Voids
- Suekdccia
- · Replies 1 ·
Graduate What is the maximal comoving distance that a space probe can reach?
- Omega Force
- · Replies 1 ·
Undergrad Solar anomaly and the Antikythera Mechanism
- Bobhare
- · Replies 6 ·
Undergrad Vacuum up-tunneling with high-energy events?
- Suekdccia
- · Replies 0 ·
High School Would three suns reduce weight on a planet?
- DaveC426913
- · Replies 8 ·
Graduate A question from a paper on perturbation theory
- Safinaz
- · Replies 1 ·
High School Terminology for motion in the solar system, ecliptic maybe?
- Albertgauss
- · Replies 13 ·
Stargazing Eye protection while watching a total solar eclipse
- DrClaude
- · Replies 41 ·
Graduate Friedmann-Lemaitre-Robertson-Walker model
- Nicole01
- · Replies 9 ·
Undergrad Atmospheric escape parametre statistics
- snorkack
- · Replies 1 ·
Undergrad Stellar evolution path and Regression line
- hongseok
- · Replies 12 ·
Undergrad Why do neutron stars and black holes both have 0.4c accretion discs?
- davLev
- · Replies 48 ·
Graduate Atmospheric Density Required for Mercury´s Polar Regions to be Warm?
- snorkack
- · Replies 2 ·
Undergrad How Can Measured Satellite Magnitudes Be Converted to Radiant Intensity?
- Jd1431
- · Replies 0 ·
Undergrad Is the Sun's photosphere fluorescent?
- synch
- · Replies 22 ·
High School Layman's summary of water telescope experiments
- Devildog
- · Replies 1 ·
High School Photographing a solar eclipse with a smartphone (safely)
- Andy Resnick
- · Replies 25 ·
High School Why isn't there an effort to name non-stellar celestial objects?
- Nathi ORea
- · Replies 21 ·
High School Rock Found in Field Turns Out to Be 4.6GY Old Meteorite
- Keith_McClary
- · Replies 8 ·
Undergrad Fourier transform of the density fluctuation
- happyparticle
- · Replies 2 ·
Graduate How do I determine the surface magnitude of a galaxy from a SED?
- AdrianD
- · Replies 1 ·
Undergrad What is the Freeze-Out Temperature of WIMP Particles?
- happyparticle
- · Replies 4 ·
Undergrad What are the Dynamics and Impacts of a Type II Supernova?
- RyanJ
- · Replies 11 ·
Undergrad Why Does Spectral Line Darkening Occur Despite Photon Re-Emission?
- Joe Prendergast
- · Replies 2 ·
High School How Is Solar Wind Temperature Measured?
- jefo
- · Replies 20 ·
High School What is the difference between a rocky planet's core and the Sun's core
- trevorjobo83
- · Replies 5 ·
Undergrad Adding more meteorites to my collection
- davenn
- · Replies 84 ·
High School Can the force of gravity overcome the Planck force?
- mister i
- · Replies 11 ·
Undergrad Is Gravitational Red-Blue Shift Dismissed in Cosmic Observations?
- trevorjobo83
- · Replies 12 ·
High School Do we 100% know what the geometry of the Universe is?
- user079622
- · Replies 38 ·
Undergrad Do the Sachs-Wolfe and Rees-Sciama Effects Influence Matter?
- Suekdccia
- · Replies 0 ·
High School Can Spacetime be Torn According to Quantum Theory of Gravity?
- singularity18
- · Replies 10 ·
Undergrad Relationship Between Expansion and Curvature in the Universe
- Jaime Rudas
- · Replies 3 ·
Undergrad How Does Curvature Density Parameter Affect Universe Flatness?
- Ranku
- · Replies 9 ·
High School Could Dark Energy be an (unknown) dark force acting at great distances?
- mister i
- · Replies 7 ·
High School How did ancient astronomers track changes in positions of stars?
- syfry
- · Replies 13 ·
High School Why don't iron stars evaporate from Hawking radiation before proton decay?
- Khursed
- · Replies 7 ·
High School Sunspots visible in sunset timelapse from July 6, 2023
- Glenstr
- · Replies 6 ·
Undergrad Boltzmann equation for annihilation
- happyparticle
- · Replies 6 ·
Sample and Return of Asteroid Bennu - live on Oct 20, 2020 at 1720 GMT
- Tom.G
- · Replies 23 ·
Identifying magnetic rocks and possible meteorites
- leerace
- · Replies 5 ·
Undergrad Separation angle between pulsars detecting Gravitational Waves
- zinn
- · Replies 0 ·
Stargazing What is an arcsec and how do I convert it into AU or m?
- marc873a
- · Replies 8 ·
Undergrad Voids, dark energy and tidal forces...?
- Suekdccia
- · Replies 0 ·
High School Where does the original singularity get its energy from?
- Arasvo
- · Replies 10 ·
High School What Does the Astro Physics Equation from Lewis Season 8 Episode 2 Mean?
- DaveC426913
- · Replies 26 ·
Undergrad Why Does Gravity Remain when Star Mass Dissipates?
- ahandyman59
- · Replies 10 ·
Graduate Could Re-Analyzing Redshifts Reveal New Physics?
- sbrothy
- · Replies 0 ·
Stargazing Is There an Unidentified Object Near the Horsehead Nebula?
- russ_watters
- · Replies 14 ·
High School Cosmic Graviton Background and Primordial Gravitational Waves
- windy miller
- · Replies 2 ·
High School Is the barycentre of the Pluto - Charon system also the L1 point?
- Cerenkov
- · Replies 3 ·
High School Are the viral Skull and Bat Nebula images fake?
- DaveC426913
- · Replies 34 ·
Graduate Why Is the Hamiltonian Approach Preferred for the Restricted Three Body Problem?
- slyrice
- · Replies 1 ·
Undergrad Plotting the orbits of the planets from Ephemeris data
- Jor
- · Replies 1 ·
High School Observable universe and overlapping spheres
- KobiashiBooBoo
- · Replies 15 ·
High School How would physics change if Planet 9 were a primordial black hole?
- Maximum7
- · Replies 3 ·
High School Celestial plane orientation to the galactic core
- AutodiJack
- · Replies 8 ·
Undergrad Identifying a tumbling object in a night sky photo from Namibia
- timmdeeg
- · Replies 54 ·
High School Dark matter and extreme gravitational regimes
- member 563992
- · Replies 34 ·
Undergrad On Quanta article on the recent tensions of cosmology
- pines-demon
- · Replies 5 ·
Undergrad Calculating the End of the Universe Using Standard Deviation Statistics
- TomVassos
- · Replies 13 ·
Undergrad Why Do Stars in Binary Systems Assume a Teardrop Shape?
- Joe Prendergast
- · Replies 14 ·
Undergrad Mass in an expanding or static spherical distribution of matter
- Ranku
- · Replies 5 ·
High School Is perpetual motion a forbidden topic in the scientific community?
- robotkid786
- · Replies 5 ·
Undergrad Questions about the Location of the Big Bang and the Age of the Universe
- SilverMain
- · Replies 8 ·
High School Comoving distance constant with increasing redshift?
- FritzK
- · Replies 12 ·
Undergrad How does flux density scale with redshift?
- givingup
- · Replies 6 ·
Graduate Numerical evolution of Einstein-Boltzmann equations in cosmology
- chirag1
- · Replies 2 ·
Graduate Gravitational Instability and accelerated explanation of Universe?
- say_cheese
- · Replies 19 ·
Undergrad Can Hawking Radiation Exist If Nothing Escapes a Black Hole?
- Walrus
- · Replies 4 ·
Graduate What is Faraday pulsation and how does it impact radiative transfer?
- Getterdog
- · Replies 2 ·
Undergrad Photons being blueshifted when crossing evolving voids?
- Suekdccia
- · Replies 0 ·
Undergrad Falling into a massive black hole is not necessarily noticeable
- Kekkuli
- · Replies 4 ·
Graduate What Is the Scale Length in SPARC Data Analysis?
- mike_brandt
- · Replies 1 ·