Astronomy and Astrophysics Forum

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Join in expert discussion on the topics of Astronomy and astrophysics. This may include discussion on celestial objects, space, and the physical universe as a whole. Mainstream science only.
Graduate What's the fastest space pulls apart from itself?
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High School Why do the sun and moon look bigger when rising and setting?
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Graduate Applying the Virial Theorem to Stellar winds
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Graduate How Do Astrophysicists Measure Solar Mass Loss?
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High School Understanding Spectral Index: A Plain Explanation
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Undergrad Artificial Gravity: Sci-Fi Possibility & Effects
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Graduate Gravitationally bound, ionized cloud of hydrogen
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Graduate Cauchy horizon in a Kerr rotating black hole
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Undergrad Viewing size of Galaxies 7 Billion light years away?
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Graduate Hardness of Neutronium: Estimating Magnitude
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Undergrad Calculating Fuel Needed for Geosynchronous Orbit
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Graduate Baryon Asymmetry: Why is Matter More Abundant?
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High School How Long Does it Take the Moon to Orbit the Earth?
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Undergrad Early Warning against Killer -Asteroids - current state, ideas
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Undergrad What is the Significance of a Secular Timescale?
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Graduate Congratulations to all the PF gurus
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Graduate Black holes, frame dragging and the effect on gravity
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Apophis Strikes Earth: Odds still 1 in 45,000
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Undergrad How to find data on Earth, planets, motions
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Undergrad Is the Root 2 Relationship Valid for Orbital Mechanics on the Moon?
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Undergrad Hubble's Discovery of Cepheid Variable Stars in Galaxies
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Graduate The Rotation of the Universe: A New Perspective on Cosmic Expansion
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Undergrad Ratio between Semi major and Velocity
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Undergrad Rotational Motion of Celestial Body
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Undergrad Apophis to impact earth in 2036?
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Graduate What Happens to Time and Space at the Event Horizon of a Black Hole?
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Graduate Do Laws of Physics Break Beyond the Event Horizon in Kerr Black Holes?
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Undergrad Torque caused by/due to a galaxy's spin
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Graduate What Happens to Infalling Matter as a Black Hole Evaporates?
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High School What Causes Multi-Colored Stars to Twinkle in the Night Sky?
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Graduate Synchronous Moon Stability: Conditions & Twin Planet Distance
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Undergrad Will a Toy Top Keep Spinning in Space?
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Undergrad Orbiting space station is observed to remain always vertically above
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Graduate Wien's Law & Earth Emission Spectra: Investigating the discrepancy
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Stargazing Telescope alteration (Russ or turbo-1)
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Undergrad Will voyager 1 or 2 pass the heliopause
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Graduate Gravitational attraction of bodies
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Graduate So you discover the dark matter particle Now what?
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Graduate Artificial Stars: Dream or Possibility?
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High School Are Cosmic Rays Just Electromagnetic Rays from Space?
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High School The Earth and its orbit around the sun
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Graduate Why do we say black holes vanish if their mass decreases with hawking radiation?
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Where Can I Download M.V.Berry's 'Stability of the Solar System' Paper for Free?
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Graduate How fast does the universe expand and what are the theories behind it?
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Undergrad What is Dark Energy and How Does It Affect the Universe's Expansion?
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High School Are those shooting stars or satellites in the night sky?
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Online Discussion: The End of the World in 2012?
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Graduate Negative Acceleration in Black Holes
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Graduate Visualizations without space-time or light
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Graduate Angular momentum of an oblate spheroid
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Graduate Hawking radiation & Information loss
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Graduate Rotational kinetic energy and gravity
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Graduate How Do Black Hole Masses Compare to Normal Matter in the Universe?
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Graduate Titius-Bode law, any analytical or numerical derivation?
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Graduate Relativity or Relativistic Theromdynamics
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Undergrad Human versus robotic spaceflight
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Graduate What Is the Orbital Period of an Asteroid with a Temperature of 200 K?
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Graduate Discovering the Solar Corona Luminosity Curve: Explained and Explored
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Graduate What Lies Beyond Our Universe? Physicists' Opinions
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Graduate Universe doesn't equal Time travel
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Undergrad What would happen to Earth without the moon?
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High School Why Don't We Feel Earth's Movement and How Do Tides Affect Well Water Levels?
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Undergrad Gamma Ray burst in the Milkey Way
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High School Rockets in Space: Need for Engines to Change Direction
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Graduate Snowplow model of a supernova remnant
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High School Moon without Earth: What if Earth Disappears?
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High School Demonstrating Moon's Lack of Internal Rotation
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High School Finding a Local Star Like Ours: 10-50 LY Radius
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High School Sun's Energy Output: How Much & What Could it Power?
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Undergrad Why is the Earth getting closer to the sun and the moon getting farther away?
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Undergrad Naked-Eye Visible GRB: Witnessing Halfway Across All Creation
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Undergrad Why don’t planet hunters find black holes?
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High School Why do we see the near side of the moon only?
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Graduate Urban legends in authoritative astronomy
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High School Earth's Closest Approach to the Sun: Does the Date Change?
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Graduate Can Early Dark Energy Affect Standard Rulers in Cosmology?
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What are the limiting factors in this case
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Undergrad Why Does Earth's Axis Precess Like a Spinning Top?
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Graduate Minimum value of g for blackhole
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Undergrad Light Entering Black Hole: Observed or Not?
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Undergrad How Are Black Holes Detected and Measured?
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Undergrad Relation between earth position in orbit and its tilt
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Graduate Possible webpage title: Need Help with These Astronomy Questions?
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High School Newbie question on atsrophotography
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High School A Beginner's Guide to Learning About Black Holes
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Graduate Gravity for a stellar black hole
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Undergrad Can two stars have the same apparent but different absolute magnitudes
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Graduate Superbubbles from shock waves from supernova or stellar winds?
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Undergrad Earth/solar position vs spiral arms
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High School Moon Preservation: What if a Spaceshuttle or Missile Hit It?
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Undergrad What Material Makes Up Black Holes?
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Astronomy Videos: Collection by NGC6822 on YouTube
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Anybody know anything about parallelogram mounts
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Undergrad . Radio Spectroscopy -> Finding the doppler shift in a graph
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Undergrad Just a simple explanation please
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Undergrad Equatorial Bulge: Causes & Explanation
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Graduate A question regarding the orbit of material in a galaxy such as ours
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Undergrad Can two planets inhabit the same orbit?
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Undergrad Just Checking - Calculating Angular Diameter of Moon
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Graduate Can there be anything outside of our Existance?
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