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.
Undergrad How Does a CMB Photon Travel Through Expanding Universe?
  • · Replies 39 ·
2
Replies
39
Views
6K
High School 2D Model of the Universe as an expanding ball
  • · Replies 4 ·
Replies
4
Views
2K
Collector's Item For Space Buffs
  • · Replies 8 ·
Replies
8
Views
2K
Graduate Quintessence field equation of state
  • · Replies 3 ·
Replies
3
Views
2K
High School Need your advice how to start learning astronomy
  • · Replies 17 ·
Replies
17
Views
3K
High School Gravitational fields affecting each other?
  • · Replies 21 ·
Replies
21
Views
3K
High School Is it a Meteorite? Las Vegas Hiker Finds 81.7g Object
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Will stars on the other side of the galaxy affect gravity here?
  • · Replies 10 ·
Replies
10
Views
2K
Undergrad New Paper Claims Primordial Black Holes Don't Explain Dark Matter
  • · Replies 20 ·
Replies
20
Views
5K
Undergrad Are Cosmic Rays Actually Neutrinos?
  • · Replies 4 ·
Replies
4
Views
2K
High School Term for an end state of expansion?
  • · Replies 3 ·
Replies
3
Views
1K
High School Viewing distant celestial objects
  • · Replies 22 ·
Replies
22
Views
3K
High School If the universe is infinite or repeats, can "I" exist again?
  • · Replies 2 ·
Replies
2
Views
4K
Undergrad Coude Spectrograph vs Cassegrain?
  • · Replies 3 ·
Replies
3
Views
1K
Undergrad Penrose's Latest Paper on CCC: Evidence or Wishful Thinking?
  • · Replies 6 ·
Replies
6
Views
10K
Graduate Distances between observers using the Lightone7 calculator
  • · Replies 17 ·
Replies
17
Views
3K
What quirky tradition do astronauts have before launching into space?
  • · Replies 5 ·
Replies
5
Views
1K
Space travellers can run but they can't hide
  • · Replies 11 ·
Replies
11
Views
2K
Undergrad Does the external field effect prove MOND over dark matter?
  • · Replies 1 ·
Replies
1
Views
2K
High School What Would Happen if the Earth Stopped Rotating?
  • · Replies 31 ·
2
Replies
31
Views
5K
Undergrad How does a brown dwarf's temperature decrease over time?
  • · Replies 14 ·
Replies
14
Views
3K
Undergrad How can one see the noise in the Fourier Domain (Nyquist Frequency)?
  • · Replies 6 ·
Replies
6
Views
2K
Graduate Discrepancy in Jorrie’s LightCone7-2017-02-08 Cosmo-Calculator
  • · Replies 15 ·
Replies
15
Views
2K
High School Request for an up to date list of cosmological theories
  • · Replies 11 ·
Replies
11
Views
2K
Undergrad How to find the distance from a star to the center of the Milky Way Galaxy?
  • · Replies 8 ·
Replies
8
Views
5K
High School A question about which Cosmology theories are mainstream and how?
  • · Replies 5 ·
Replies
5
Views
2K
High School How common are total eclipses in the universe?
  • · Replies 21 ·
Replies
21
Views
4K
High School Early Universe Radiation: Gamma to Microwave?
  • · Replies 42 ·
2
Replies
42
Views
5K
High School Can a Planet Have a Moon that Never Casts a Shadow?
  • · Replies 19 ·
Replies
19
Views
3K
Undergrad How Do Inhomogeneities in Matter Affect Cosmic Evolution and Backreaction?
  • · Replies 10 ·
Replies
10
Views
1K
Undergrad Strange radio signal from Proxima Centauri
  • · Replies 14 ·
Replies
14
Views
3K
Undergrad Is the Ecliptic Plane the Same as the Apparent Path of the Sun?
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Questions about Isotropy in Our Universe and Implications
  • · Replies 6 ·
Replies
6
Views
1K
Undergrad What is the astronomy reason for no UHF channel 37?
  • · Replies 35 ·
2
Replies
35
Views
5K
High School Has there ever been a planet-planet eclipse (i.e., observed from Earth)?
  • · Replies 17 ·
Replies
17
Views
3K
High School Does matter accumulate in Earth's gravity well?
  • · Replies 38 ·
2
Replies
38
Views
5K
Undergrad Solar chromosphere: inter-conversion of Ca I, Ca II, role of photons
  • · Replies 2 ·
Replies
2
Views
1K
Undergrad What is a "temperature distribution" in a stellar photosphere?
  • · Replies 1 ·
Replies
1
Views
1K
Undergrad Which forces maintain the shape of the Milky Way?
  • · Replies 16 ·
Replies
16
Views
2K
High School 'A Brief History of Time' question on gravity
  • · Replies 4 ·
Replies
4
Views
2K
High School Mars Landing, How instantaneous communication was possible
  • · Replies 10 ·
Replies
10
Views
5K
Graduate Description of Titan and Potential Approaches to its Exploration
  • · Replies 2 ·
Replies
2
Views
1K
High School What force keeps the planets orbiting normally?
  • · Replies 10 ·
Replies
10
Views
2K
Undergrad How do Limb-Darkening curves differ at two different wavelengths?
  • · Replies 1 ·
Replies
1
Views
1K
Undergrad Why is Mars not considered a "full-fledged" planet?
  • · Replies 9 ·
Replies
9
Views
3K
High School "Snow" on comet 67P/Churyumov-Gerasimenko is actually stars
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Are there more Pulsars than we observe?
  • · Replies 6 ·
Replies
6
Views
2K
Stargazing Will the supernova explosion of Betelgeuse influence the Earth?
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad How to compute the expansion of this congruence?
  • · Replies 7 ·
Replies
7
Views
1K
Undergrad What is the current status of the Hubble-tension?
  • · Replies 8 ·
Replies
8
Views
2K
High School Tidal locking for planets of K type (orange) dwarf stars
  • · Replies 2 ·
Replies
2
Views
4K
Undergrad Will the Sun end as a Type 1a supernova?
  • · Replies 9 ·
Replies
9
Views
2K
Undergrad When was the matter density equal to the vacuum energy density?
  • · Replies 2 ·
Replies
2
Views
2K
Graduate What are the parameters that are the same in CMB data for multiple models?
  • · Replies 8 ·
Replies
8
Views
2K
High School How the Earth's Magnetic field deflects the solar wind
  • · Replies 5 ·
Replies
5
Views
3K
Undergrad Follow an object into a black hole
  • · Replies 12 ·
Replies
12
Views
2K
Undergrad What are the key characteristics of rivals to inflation in cosmology?
  • · Replies 14 ·
Replies
14
Views
3K
Undergrad The stellar system genesis & supernova cycle
  • · Replies 1 ·
Replies
1
Views
2K
Stargazing Where to find more material about LORENE software?
  • · Replies 1 ·
Replies
1
Views
1K
High School Value of G Changing Over Time?
  • · Replies 22 ·
Replies
22
Views
2K
Graduate Solve Stellar Structure with Lane-Emden Equation
  • · Replies 2 ·
Replies
2
Views
2K
High School Next Generation Planetary Missions Hunt for Gravitational Waves
  • · Replies 1 ·
Replies
1
Views
1K
High School Understanding the Mass of Solar Wind and its Impact on Earth's Surface
  • · Replies 12 ·
Replies
12
Views
2K
Stargazing Is There a Common Pattern in Einstein Crosses?
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Dark Energy's Effect on Black Holes
  • · Replies 13 ·
Replies
13
Views
2K
High School Planetary debris found in white dwarf atmospheres
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Solve Fermi's Non-Paradox: Astronomers Weigh In
  • · Replies 45 ·
2
Replies
45
Views
7K
Undergrad Hubble deep field & ancient galaxies
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad What is the rate of ejecta deposited between planets?
  • · Replies 7 ·
Replies
7
Views
2K
High School What is the true density of the Asteroid Belt?
  • · Replies 17 ·
Replies
17
Views
4K
High School How can the Observable Universe be a closed system?
  • · Replies 37 ·
2
Replies
37
Views
7K
Graduate Combining 2 probes in order to increase Figure of Merit
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad How big will the Betelgeuse supernova appear?
  • · Replies 8 ·
Replies
8
Views
3K
Undergrad If Ouamuamua were a propelled lightsail, wouldn't we have detected it?
  • · Replies 6 ·
Replies
6
Views
1K
High School The Universe is now closed and curved?
  • · Replies 26 ·
Replies
26
Views
4K
High School Dark Matter -- Is it possible that Dark Matter has Planck mass and Spin two?
  • · Replies 13 ·
Replies
13
Views
2K
Stargazing Can distance in space be measured by human systems?
  • · Replies 22 ·
Replies
22
Views
4K
High School Does Dark Matter Have a Periodic Table?
  • · Replies 12 ·
Replies
12
Views
2K
High School Trying to understand the differences between distant & local galaxies
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Solar System Diameter: Calculating Distances & Multi-Star Systems
  • · Replies 2 ·
Replies
2
Views
3K
High School Is the Universe Expanding Due to Spinning?
  • · Replies 9 ·
Replies
9
Views
3K
Undergrad Are masers orbiting black holes a reliable standard ruler in cosmology?
  • · Replies 11 ·
Replies
11
Views
3K
Undergrad Can Einstein-Chwolson rings be observed from a telescope on Earth?
  • · Replies 5 ·
Replies
5
Views
2K
High School Darkest Place on the Surface of the Earth
  • · Replies 8 ·
Replies
8
Views
2K
Graduate Is there a closed form solution to Kepler's problem?
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Is dark energy pushing or is it a mirror concept of gravity?
  • · Replies 31 ·
2
Replies
31
Views
4K
Undergrad Ignite Jupiter? Could Earthlike Planets Exist in Its Atmosphere?
  • · Replies 7 ·
Replies
7
Views
3K
Graduate Life supported by radiation from the accretion disk of a black hole
  • · Replies 1 ·
Replies
1
Views
2K
High School When does the perspective from the cockpit of a spaceship change?
  • · Replies 30 ·
2
Replies
30
Views
4K
High School Trace methane in Uranus and Neptune, condensing into diamonds
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Do stars in the ecliptic seasonally change brightness?
  • · Replies 13 ·
Replies
13
Views
2K
Stargazing Is this USB eyepiece camera a lemon?
  • · Replies 26 ·
Replies
26
Views
4K
Undergrad Accelerating Universe and spherical distribution of matter
  • · Replies 9 ·
Replies
9
Views
2K
High School Meteor Photographed by Accident: Spectacular Green Bolide
  • · Replies 11 ·
Replies
11
Views
2K
High School Did the Big Bang expand faster than light?
  • · Replies 26 ·
Replies
26
Views
4K
High School Can We See Beyond the Voids in Our Universe?
  • · Replies 14 ·
Replies
14
Views
2K
High School Creation and distribution of elements - looking for recommendations
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Was the Ancient Universe More Compact Between 12,000 BC and 400 BC?
  • · Replies 9 ·
Replies
9
Views
2K
High School Are Most Star Systems Composed Mainly of Light Elements?
  • · Replies 3 ·
Replies
3
Views
1K
High School Will You Capture Jupiter and Saturn's Historic Conjunction?
  • · Replies 28 ·
Replies
28
Views
5K