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.
High School How to calculate Aphelion distance?
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High School What keeps most galactic stars from falling into the centeral black hole?
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High School How Do We Calculate the Number of Atoms in the Universe?
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Undergrad Is Dark Matter the Key to Understanding the Pre-Visible Universe?
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Undergrad Can You Build Your Own Radio Telescope at Home?
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High School Visible Light Through a Wormhole
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High School First light from the Euclid telescope
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Undergrad Question on multiple rebrightening gamma ray bursts and gravity waves
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Undergrad Telling time on Iapetus and other general questions about Iapetus
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Graduate Convention of units for densities in cosmology
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Undergrad Dark Energy contribution to plasma temperature in galaxy clusters?
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Undergrad An asteroid the size of the Rose Bowl has a slight chance of impacting Earth?
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Undergrad Solar Calendar -- When was the leap day inserted?
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Undergrad How Can We Measure Properties of Distant Planets and Stars?
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Undergrad Nuclear reactions in the Sun and other topics on stars
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Undergrad Formation of emission lines and other topics
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Undergrad Star cluster in the Milky Way appears to be as old as the Universe
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Undergrad Is Tipler's Theory of Immortality Worth Considering Without Religious Bias?
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Undergrad Big bang occuring everywhere vs everything "compressed"
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High School Does the Universe prefer certain kinds of matter based on the laws in place?
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Undergrad Using GR to predict the shape of the entire universe?
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Undergrad How does gravitational self-interaction affect the Milky Way Galaxy?
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Undergrad Understanding Space-Time Expansion: Debunking the Myth of Non-Physical Space
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High School What value of z (redshift) equals apparent superluminal recession?
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Undergrad Limitations of Observing Distant Space Objects
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High School Can Jupiter gravitationally eject a pebble in orbit? A smaller mass?
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High School Supernova Ejection: How Large Are the Chunks?
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Undergrad Is it possible to build a Telescope the Size of Half the Solar System size using all Lagrange Points?
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Graduate Save Time with CLASS Code: Neat Trick for Background Quantity Evolution
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Stargazing Understanding the Formula for Sunrise and Sunset Calculation
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Undergrad Tidal effects of galaxies orbiting one another with dark energy?
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Stargazing How can we be sure that Leavitt’s law works?
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High School Annular eclipse October 14, 2023
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Undergrad Why Is a Flat Universe Infinite?
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Undergrad What are P03 procedures or guidelines?
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High School Roger Penrose model of the rebirthing universe
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High School How did expansion take 380,000 years to let light travel freely?
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Undergrad Cosmological expansion of space - question
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High School Can anyone suggest a good website to buy astronomy equipment?
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High School Which star is the closest red giant to Earth according to The Guardian?
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High School Is the existence of Planet 9 supported by Modified Newtonian Dynamics?
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Undergrad “Interpreting astronomical spectra” -- Continuum origins
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Undergrad Same state as in the Big Bang in a collapsing universe?
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Undergrad Effects of gravity on planetary core structure
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High School Am I attracted to a hydrogen atom 1 billion light years away?
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Undergrad Location of the magnetopause using Chapman-Ferraro equation
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Graduate NASA's DART spaceship has hit the Dimorphos asteroid: what now?
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Undergrad Dark energy contributing to, or modifying, mass estimates?
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Graduate Why the James Webb Space Telescope needs propellant
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High School Why Does an Einstein Ring Have Four Images?
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High School Difference between autumnal and vernal equinoxes
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High School The distance to the nearest identical Hubble volume in light years?
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Undergrad Resolution of observation telescopes?
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Undergrad Can astronomical observation take place in daylight in Antacrtica?
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Graduate Poisson noise on ##a_{\ell m}## complex number: real or complex?
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Undergrad What was expansion speed at the time of the CMB?
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Undergrad Is El Gordo's Collision Velocity Challenging ΛCDM?
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High School SubNeptune planet K2-18b shows methane and dimethyl sulfide
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High School Questions about relative Space-Time in the Universe
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Undergrad Doubts about isotropy of space
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Undergrad Surely the 2nd Law of Thermodynamics is defied by gravity?
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Undergrad Working model to demonstrate Lagrange points L4 & L5 -- possible?
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High School Why is spacetime shown on a 2 dimensional plane?
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Undergrad The boundary conditions at infinity
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Undergrad Formation of rocky planets without a star
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High School Do changes in speed always affect orbit size, and vice versa?
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Undergrad Unobservable Universe and the CMBR
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Undergrad Formation of jets with accretion disks at black holes
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Undergrad Inquiry Regarding the Determination of the Galactic Disk's Outer Bound
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Undergrad Why Didn't Henrietta Leavitt Sign Her Own Discovery Paper?
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High School A Question about Cosmic Background Noise
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Undergrad Would there be any way to avoid gravitational wave emissions?
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Undergrad Role of Dark Matter in the Evolution of Large Scale Structure
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Undergrad Comparing the formation of the atmospheres on Earth vs Venus
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High School More Evidence for MOND -- Globular cluster galactic acceleration imprint
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Undergrad Does the Cosmological Principle in any way underpin Big Bang Theory?
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Undergrad "Quasar clocks" and time running slower long ago
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Undergrad The theoretical basis for a hot Big Bang?
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Undergrad Seeking Visualization Tools for Hypothetical Black Hole Concept
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Undergrad Ancient galaxies: lack of mergers vs. subsequent spatial expansion
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Undergrad Obtaining Transit Spectrum for Celestial Bodies Using JWST NIRSPEC
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Graduate How to convert mW/m^2 to W/m^2/nm?
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Undergrad Cosmological red shift and cosmic time dilation
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Undergrad What is the accuracy of parking spacecraft into Lagrange points?
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Undergrad Entropy reversal in an infinite static universe?
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Undergrad Longest day of the year is June 21 but longest daylight is June 26?
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High School What does it mean to say the Universe is the same everywhere?
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Graduate Advice needed for exposure time computation for galaxies
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Undergrad DeSitter cosmological horizon stability?
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Undergrad Anyone know about the bolide across the Gulf Coast Fri July 14, 2023?
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Undergrad Could entropy be reversed eventually in the far future?
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Undergrad Error in Euler angles and quaternions
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High School How can a single Big Bang be true?
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Undergrad Without degeneracy, when would Solar cores collapse?
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Stargazing Question about my photos of a Full Moon -- What is this point of light?
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High School Can BepiColombo Detect Microbial Life on Mercury?
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Undergrad Lines of stars that we see in the sky
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Undergrad Einstein, Friedman and the cosmological constant
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Undergrad James Webb telescope calibration
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Graduate Largest Galaxy In An Infinite Universe
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