Astronomy and Astrophysics Forum

Post thread
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.
Why Does the Hubble Sphere Expand Despite the Changing Hubble Constant?
  • · Replies 6 ·
Replies
6
Views
3K
Is Newton's third law applicable everywhere?
  • · Replies 6 ·
Replies
6
Views
6K
Solar System Dynamics, advice for a intern.
  • · Replies 1 ·
Replies
1
Views
1K
Proton-electron mass ratio; changed? how much?
  • · Replies 6 ·
Replies
6
Views
3K
Shape of Galaxies: Explaining Spiral & Elliptical Structures
  • · Replies 9 ·
Replies
9
Views
3K
Solar System inside a black hole
  • · Replies 3 ·
Replies
3
Views
2K
What is the Ideal System for Running a Nuclear-Powered Heat Engine in Space?
  • · Replies 12 ·
Replies
12
Views
2K
Ison Comet will be brighter than the moon
  • · Replies 27 ·
Replies
27
Views
11K
Have you seen the meteoric smoke-ring?
  • · Replies 4 ·
Replies
4
Views
2K
Can I Use a Telecentric Lens with an Afocal Telescope?
  • · Replies 1 ·
Replies
1
Views
1K
Fire in Low Gravity: Visualizing a Biodome Blaze
  • · Replies 5 ·
Replies
5
Views
3K
Schonberg-Chandrasekhar mass for low mass stars
  • · Replies 4 ·
Replies
4
Views
3K
Help calculating The mass of a Black hole (homework help)
  • · Replies 9 ·
Replies
9
Views
2K
Plank length / space expansion question
  • · Replies 5 ·
Replies
5
Views
2K
"Planet formation captured in photo"
  • · Replies 1 ·
Replies
1
Views
2K
Worship, Reference Points & Time: A Story of an Old Lady
  • · Replies 2 ·
Replies
2
Views
1K
Does Antimatter exist in the universe anymore?
  • · Replies 44 ·
2
Replies
44
Views
9K
What are peoples thoughts on the fact that at the exact limit of our universe.
  • · Replies 6 ·
Replies
6
Views
1K
How Did the First Stars Form Without Supernova Compression?
  • · Replies 1 ·
Replies
1
Views
2K
How did Einstein know the properties of space and time
  • · Replies 4 ·
Replies
4
Views
1K
Can someone explain the mathematics of this formula for Venus' orbit
  • · Replies 5 ·
Replies
5
Views
4K
Virgin Galactic's SpaceShipTwo Lost in Test Flight; One Pilot Reported Dead
  • · Replies 39 ·
2
Replies
39
Views
3K
What prevents a star from collapsing after stellar death?
  • · Replies 51 ·
2
Replies
51
Views
9K
Zero gravity in spiral galaxy center?
  • · Replies 5 ·
Replies
5
Views
3K
Tides: Does Moon's Rotation Affect Earth?
  • · Replies 1 ·
Replies
1
Views
2K
Mom's New Camera Captures the Night Sky!
  • · Replies 5 ·
Replies
5
Views
1K
Unorthodox "space" elevator idea
  • · Replies 3 ·
Replies
3
Views
2K
Why do galaxies and solarsystems form disks?
  • · Replies 4 ·
Replies
4
Views
4K
Doubt about Frame Dragging and planetary revolution
  • · Replies 4 ·
Replies
4
Views
2K
The Space Between Atoms -- Teaching Middle School
  • · Replies 37 ·
2
Replies
37
Views
6K
Unraveling the Relationship Between Magnetic North and Solar East
  • · Replies 6 ·
Replies
6
Views
2K
UFO or Dead Pixel? What's Flying Across the Moon?
  • · Replies 9 ·
Replies
9
Views
2K
Why do the constellations appear to move differently in different seasons?
  • · Replies 6 ·
Replies
6
Views
2K
BH to Sun, back of the napkin calculation of solar mass
  • · Replies 6 ·
Replies
6
Views
2K
Results from TLE & SGP4 propagation - don't seem right & with interpretation
  • · Replies 1 ·
Replies
1
Views
3K
Can a planet with a thin atmosphere have oceans?
  • · Replies 23 ·
Replies
23
Views
4K
Which Stars Cast the Milky Way's First Light?
  • · Replies 3 ·
Replies
3
Views
2K
How Can You Find M31 in the Light-Polluted Skies of Central USA?
  • · Replies 10 ·
Replies
10
Views
2K
Is CNO cycle more life friendly than H->He?
  • · Replies 23 ·
Replies
23
Views
3K
Easy astronomical objects to see from the city
  • · Replies 14 ·
Replies
14
Views
4K
ISS Visibility If Painted Black?
  • · Replies 4 ·
Replies
4
Views
1K
What is the Density Change Towards the Centre of a Gas Giant?
  • · Replies 2 ·
Replies
2
Views
2K
What Makes the Andromeda Galaxy So Captivating in This Stunning Image?
  • · Replies 4 ·
Replies
4
Views
1K
Would the sky be red if the atmosphere was thicker?
  • · Replies 9 ·
Replies
9
Views
8K
If the sun becomes a black hole will its schwarzschild radius change?
  • · Replies 2 ·
Replies
2
Views
3K
What is the significance of the foci in gravitational orbits?
  • · Replies 2 ·
Replies
2
Views
2K
I saw the 23 Oct 2014 N America partial solar eclipse
  • · Replies 2 ·
Replies
2
Views
1K
"Churning galaxy boasts a fiery halo of baby stars"
  • · Replies 1 ·
Replies
1
Views
2K
White dwarf mass-radius relationship
  • · Replies 7 ·
Replies
7
Views
6K
Boundaries between the Constellations
  • · Replies 2 ·
Replies
2
Views
2K
Were all galaxies quasars when they were young?
  • · Replies 2 ·
Replies
2
Views
2K
Moon Phases: Rise & Set Timings & Direction Explained
  • · Replies 3 ·
Replies
3
Views
2K
I require help with understanding beginner astronomy questions.
  • · Replies 4 ·
Replies
4
Views
2K
How is the Rotational Velocity of Galaxies Measured?
  • · Replies 3 ·
Replies
3
Views
2K
How Stars Ignite - The Fusion Reaction
  • · Replies 13 ·
Replies
13
Views
12K
Determine the least value of declination of stars so that stars can be seen?
  • · Replies 3 ·
Replies
3
Views
2K
Can a Balloon Float Inside a Hollow, Air-Filled Space Elevator?
  • · Replies 4 ·
Replies
4
Views
2K
What's the scale on Mars rover "Microscopic Imager" images ?
  • · Replies 2 ·
Replies
2
Views
3K
Measuring Cosmic Rays: There's an App for that
  • · Replies 1 ·
Replies
1
Views
2K
Uranus' closest approach to earth and its interval
  • · Replies 4 ·
Replies
4
Views
2K
What exactly is the Hubble parameter?
  • · Replies 7 ·
Replies
7
Views
2K
Kepler's 3rd Law: Solving Questions & Math
  • · Replies 3 ·
Replies
3
Views
3K
Lagrange Point and orbital velocity
  • · Replies 2 ·
Replies
2
Views
2K
What would you do if you were in space
  • · Replies 1 ·
Replies
1
Views
1K
Is the universe NOT accelerating ?
  • · Replies 5 ·
Replies
5
Views
2K
Solar Cycle: Current State & Update
  • · Replies 5 ·
Replies
5
Views
2K
How can I determine right ascension and declination of a star in the sky?
  • · Replies 4 ·
Replies
4
Views
7K
Total Lunar Eclipse 8th Oct 2014
  • · Replies 23 ·
Replies
23
Views
3K
Stargazing Is a Geo Stationary Satellite the Key to Building the World's Biggest Telescope?
  • · Replies 10 ·
Replies
10
Views
5K
Inertia in Space: Opening a Hatch
  • · Replies 13 ·
Replies
13
Views
3K
ULXs & Black Holes: Unveiling Secrets of Escape Velocity
  • · Replies 6 ·
Replies
6
Views
2K
Is Dark Matter Only Interacting Through Gravity or Are There Other Theories?
  • · Replies 19 ·
Replies
19
Views
3K
Calculating Exoplanet Habitability using Stefan-Boltzmann Law | Habitable Zones
  • · Replies 15 ·
Replies
15
Views
4K
Introdutions to mathematical astronomy?
  • · Replies 1 ·
Replies
1
Views
856
Reynolds Number and Turbulence in Atmospheric Boundary Layers
  • · Replies 4 ·
Replies
4
Views
4K
Could the Big Bang be related to the flow of current in vacuum tubes?
  • · Replies 7 ·
Replies
7
Views
2K
Is a Connection Between Black Holes and Time Machines Possible?
  • · Replies 4 ·
Replies
4
Views
2K
Relationship between Ultracold neutrons and neutron stars
  • · Replies 6 ·
Replies
6
Views
3K
A Question Concerning Solar Flares
  • · Replies 8 ·
Replies
8
Views
3K
Are neutrons in a neutron star relativistic?
  • · Replies 15 ·
Replies
15
Views
5K
Can Microorganisms Help Us Understand Aging Rates on Other Planets?
  • · Replies 4 ·
Replies
4
Views
4K
Can You Orbit the Photon Sphere Without Being Pulled into the Event Horizon?
  • · Replies 2 ·
Replies
2
Views
2K
Could Super-Bacteria from Space Pose a Threat to Earth?
  • · Replies 1 ·
Replies
1
Views
2K
Gravitational Lens with home scope?
  • · Replies 2 ·
Replies
2
Views
1K
Who should we give credit for considering the possibility of Black Hole?
  • · Replies 6 ·
Replies
6
Views
2K
How far from Event horizon are you safe?
  • · Replies 7 ·
Replies
7
Views
5K
Why is stellar ash found in the core of a White Dwarf so dense?
  • · Replies 2 ·
Replies
2
Views
2K
The fabric of the cosmos - Universe or Multiverse
  • · Replies 2 ·
Replies
2
Views
3K
How can black holes coexist with the expanding universe?
  • · Replies 22 ·
Replies
22
Views
5K
Gravity and Gas Pressure on an Accelerating Object
  • · Replies 2 ·
Replies
2
Views
1K
How does solar wind effects Geomagnetic Field?
  • · Replies 5 ·
Replies
5
Views
3K
Stargazing UY Scuti, the biggest known star, viewed through a telescope
  • · Replies 6 ·
Replies
6
Views
11K
Oldest part of the galaxy that could have held life?
  • · Replies 1 ·
Replies
1
Views
2K
Inhabitable planets at doable distances ever or somewhere?
  • · Replies 21 ·
Replies
21
Views
4K
Cross-Referencing MK5(SAO) & BD-HD Numbers with Constellations, NGCs & ICs
  • · Replies 1 ·
Replies
1
Views
2K
Detecting more than 1 exoplanet using Radial Velocity Method.
  • · Replies 4 ·
Replies
4
Views
6K
Deriving the rayleigh-jeans limit of planck law of radiation
  • · Replies 1 ·
Replies
1
Views
4K
Gravitational pull of manmade satellites
  • · Replies 4 ·
Replies
4
Views
2K
Meteoritical History of the Solar System
  • · Replies 3 ·
Replies
3
Views
3K
Stargazing Mirror Mounting Structure in Space Telescope
  • · Replies 1 ·
Replies
1
Views
1K