Astronomy, Astrophysics, Cosmology Forum

Post thread
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.
Stargazing Castor, Pollux, Mars and the Moon
  • · Replies 1 ·
Replies
1
Views
3K
Stargazing Partial Solar Eclipse, From Southern New Zealand
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Are There Two Suns? Exploring the Phenomenon of Sun Dogs
  • · Replies 4 ·
Replies
4
Views
2K
High School Asteroid 2024 YR4 has a 1% risk of a multi-megaton impact in 2032 (now ruled out)
  • · Replies 35 ·
2
Replies
35
Views
10K
High School Matter density right after the decoupling
  • · Replies 13 ·
Replies
13
Views
2K
High School Why Does Titan Have an Atmosphere While Other Large Moons Don't?
  • · Replies 16 ·
Replies
16
Views
3K
High School Venus and Jupiter Conjunction
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Potential biosignature found in Mars rock
  • · Replies 13 ·
Replies
13
Views
2K
Undergrad Does it make sense to build new radio telescopes?
  • · Replies 46 ·
2
Replies
46
Views
4K
High School Inflation after Atacama Cosmology Telescope Results
  • · Replies 3 ·
Replies
3
Views
2K
Graduate Could gamma-ray bursts have an intragalactic origin?
  • · Replies 29 ·
Replies
29
Views
2K
Stargazing Orange lines on Aladin lite
  • · Replies 3 ·
Replies
3
Views
2K
Graduate Why do both poles of a radio pulsar emit radio waves?
  • · Replies 7 ·
Replies
7
Views
2K
Undergrad Could fast radio bursts be alien radar signals?
  • · Replies 9 ·
Replies
9
Views
2K
High School Looking for a list of astronomy collaborations
  • · Replies 2 ·
Replies
2
Views
4K
High School Does Time Pass at Different Rates on Other Planets?
  • · Replies 19 ·
Replies
19
Views
3K
Graduate Self-gravitating systems and MOND
  • · Replies 11 ·
Replies
11
Views
2K
High School Realism about singularity
  • · Replies 38 ·
2
Replies
38
Views
4K
Undergrad How to explain the strange pulsar in the Crab Nebula?
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Why are continuously emitting radio pulsars not detected?
  • · Replies 30 ·
2
Replies
30
Views
4K
Undergrad Time interval terminology
  • · Replies 6 ·
Replies
6
Views
2K
Graduate Charge to mass ratio of a photon
  • · Replies 15 ·
Replies
15
Views
3K
High School Simulating the Universe's First Stars - The Population III Stars
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Cosmological perturbations and CMBR anisotropies
  • · Replies 3 ·
Replies
3
Views
2K
High School What is conformal time?
  • · Replies 10 ·
Replies
10
Views
2K
High School Cosmic Microwave Background Stage 4 Cancelled for now
  • · Replies 4 ·
Replies
4
Views
3K
High School Feasibility of Sending a Radio Signal Detectable from a Neighboring Star
  • · Replies 5 ·
Replies
5
Views
2K
High School How Can Interstellar Asteroids Be Analyzed Using Orbital Mechanics Equations?
  • · Replies 22 ·
Replies
22
Views
2K
Undergrad How Does the Balloon Analogy Explain the Expansion of the Universe?
  • · Replies 5 ·
Replies
5
Views
3K
Undergrad Is Introducing a New Cosmological Model Based on Aether Theory Permissible Here?
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad No symmetries in the Universe at the Big Bang...?
  • · Replies 12 ·
Replies
12
Views
5K
High School Flatlander analogy of spherical surface as observable universe
  • · Replies 6 ·
Replies
6
Views
2K
High School Conflict between the conservation of matter and the rapid expansion of our universe
  • · Replies 18 ·
Replies
18
Views
3K
Undergrad Sun gravitational lensing forces
  • · Replies 11 ·
Replies
11
Views
3K
High School Where can I find easy-to-understand GAIA exoplanet data?
  • · Replies 4 ·
Replies
4
Views
3K
Undergrad The impact of early galaxy formation on the CMBR
  • · Replies 20 ·
Replies
20
Views
4K
High School Sun's peak wavelengths and chlorophyll's green colour
  • · Replies 27 ·
Replies
27
Views
4K
Graduate Understanding the Gravitational Redshift Caused by a Black Hole
  • · Replies 9 ·
Replies
9
Views
3K
High School How well do we understand the formation of population III stars?
  • · Replies 7 ·
Replies
7
Views
4K
Undergrad Questions on Expansion of the Universe and Newtonian Physics
  • · Replies 7 ·
Replies
7
Views
3K
High School Strange spiral structure in Oort Cloud, outer Solar System
  • · Replies 2 ·
Replies
2
Views
3K
Undergrad How 'Messy' are Fusion Reaction Chains in Stars?
  • · Replies 6 ·
Replies
6
Views
5K
High School Big Bang and Infinite Universe
  • · Replies 20 ·
Replies
20
Views
4K
High School Strongest hints yet of biological activity outside the solar system
  • · Replies 21 ·
Replies
21
Views
5K
Undergrad How to calculate the mass within the Hubble Sphere?
  • · Replies 3 ·
Replies
3
Views
2K
Graduate Hubble tension -- any resolution?
  • · Replies 94 ·
4
Replies
94
Views
13K
High School Can You Ace Harvard's Galactic Quiz?
  • · Replies 27 ·
Replies
27
Views
4K
Undergrad Help with my Polar Aligning Star Tracker please
  • · Replies 18 ·
Replies
18
Views
5K
Undergrad Dark Matter , Dark energy and the Dirac equation
  • · Replies 3 ·
Replies
3
Views
2K
High School What Factors Influence the Survival and Growth of Accreting Bodies in Space?
  • · Replies 10 ·
Replies
10
Views
3K
High School Trying to understand orbiting objects in space
  • · Replies 8 ·
Replies
8
Views
4K
Undergrad IRAF 2025?
  • · Replies 3 ·
Replies
3
Views
3K
Undergrad If We Crack the Neutron Star Equation of State, How Will It Change Our Daily Lives?
  • · Replies 12 ·
Replies
12
Views
4K
High School Colliding Gas Cloud to form a Star
  • · Replies 3 ·
Replies
3
Views
3K
High School Could Black Hole Collisions Trigger a Cyclical Big Bang and Universe Rebirth?
  • · Replies 19 ·
Replies
19
Views
3K
Undergrad Gravitational wave effects on different materials
  • · Replies 4 ·
Replies
4
Views
3K
High School Thought experiment to compare the present with the future flow of time
  • · Replies 7 ·
Replies
7
Views
3K
High School Proper time of the observer resting in CMB reference frame
  • · Replies 70 ·
3
Replies
70
Views
6K
How Can I Enhance My Deep Sky Images and Identify Celestial Objects?
  • · Replies 8 ·
Replies
8
Views
4K
Undergrad How do you get to the conclusion that there is accelerating expansion?
  • · Replies 23 ·
Replies
23
Views
4K
Undergrad Inflation Models that don't produce Multiverse?
  • · Replies 5 ·
Replies
5
Views
3K
High School What has space exploration done for me as an individual?
  • · Replies 16 ·
Replies
16
Views
3K
High School What Would You See at the Edge of the Expanding Universe?
  • · Replies 17 ·
Replies
17
Views
3K
High School Does an infinite universe contradict a Big Bang origin?
  • · Replies 65 ·
3
Replies
65
Views
11K
Stargazing Small angle lunar haloes
  • · Replies 5 ·
Replies
5
Views
4K
Graduate Did scientists just find that the Universe has finite angular momentum?
  • · Replies 12 ·
Replies
12
Views
5K
High School Confusion regarding black hole spin
  • · Replies 40 ·
2
Replies
40
Views
6K
Undergrad Mass Loss on an HR diagram
  • · Replies 1 ·
Replies
1
Views
3K
Undergrad Magnitude where the Pale Dot is blue?
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Is the amount of dark matter constant in the Universe?
  • · Replies 20 ·
Replies
20
Views
4K
Graduate Classifying Milky Way planets by what they´re bound to and originate from
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Galaxy GNZ11 33 billion light-years away
  • · Replies 7 ·
Replies
7
Views
3K
High School First ever recorded planetary engulfment
  • · Replies 3 ·
Replies
3
Views
4K
Undergrad If white holes were to exist in our Universe
  • · Replies 30 ·
2
Replies
30
Views
6K
High School Does Sun cross planes of all binary stars?
  • · Replies 14 ·
Replies
14
Views
3K
Graduate Black Hole TON618 - Wavelength Spectrum
  • · Replies 38 ·
2
Replies
38
Views
7K
Graduate Late time and early time approximation for EOS
  • · Replies 0 ·
Replies
0
Views
2K
Stargazing Q: Meridian flip
  • · Replies 6 ·
Replies
6
Views
3K
Undergrad Will DESI confirm that the Universe isn't described by the ΛCDM model?
  • · Replies 18 ·
Replies
18
Views
5K
High School What is dark matter?
  • · Replies 10 ·
Replies
10
Views
4K
High School Is the Gaia Telescope's Shutdown Impacting Our Ability to Map the Milky Way?
  • · Replies 5 ·
Replies
5
Views
3K
Undergrad Why Do Nebulae only have Hydrogen, Oxygen and Sulfur?
  • · Replies 4 ·
Replies
4
Views
3K
Undergrad Confused about Stonyhurst Grid and jHelioViewer
  • · Replies 17 ·
Replies
17
Views
4K
Undergrad Questions on the consequence of an evolving dark energy parameter
  • · Replies 1 ·
Replies
1
Views
3K
High School Dark Matter Theory Endorsed By NASA
  • · Replies 4 ·
Replies
4
Views
3K
Undergrad Resolution of Peeble's ODE equation
  • · Replies 1 ·
Replies
1
Views
3K
High School An old spin to our Universe
  • · Replies 4 ·
Replies
4
Views
3K
Undergrad How can the Universe be infinite?
  • · Replies 6 ·
Replies
6
Views
3K
Undergrad Speediest Exoplanet System
  • · Replies 11 ·
Replies
11
Views
5K
High School How Can Black Holes Vary in Size if They Are Singularities?
  • · Replies 20 ·
Replies
20
Views
4K
High School CNO Cycle
  • · Replies 3 ·
Replies
3
Views
3K
Undergrad Can Staging Rockets Achieve Faster-Than-Light Travel Despite Relativity?
  • · Replies 8 ·
Replies
8
Views
3K
Measuring the Solar System and Universe
  • · Replies 2 ·
Replies
2
Views
2K
High School Possible explanations for meteor like observations?
  • · Replies 12 ·
Replies
12
Views
4K
  • Featured
Undergrad Early large galaxy studies
  • · Replies 10 ·
Replies
10
Views
6K
Undergrad The initial density of an object and its compression into a black hole
  • · Replies 17 ·
Replies
17
Views
7K
High School I Need Help on Understanding Some Basic Astrophysics / Sand Clock Universe
  • · Replies 5 ·
Replies
5
Views
4K
Undergrad Would discovery of a galaxy without dark matter disprove MOND?
  • · Replies 13 ·
Replies
13
Views
4K
Undergrad Cosmic ray origins
  • · Replies 1 ·
Replies
1
Views
2K
Stargazing Is There a New Planet Beyond Neptune?
  • · Replies 1 ·
Replies
1
Views
3K