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.
B Acceleration of time due to entropy
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fresh_42
B Stars massive enough to evolve into black holes
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145
S
B Delta-v from Lagrange points to lunar surface?
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145
T
B Is there a way of creating placemarks in Stellarium?
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collinsmark
B Question about the solar system and gravitational forces
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120
S
B Rock Found in Field Turns Out to Be 4.6GY Old Meteorite
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Astronuc
B Pressure under the ice of Europa?
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525
green slime
B Definition of Stellar Parallax from Alonso and Finn Volume 1
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191
Drakkith
B Bigger ears, or louder noises?
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3
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146
Vanadium 50
B What kind of orange K dwarf stars are prone to flaring?
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0
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127
Cerenkov
B Some visuals for Size of Solar System, Galaxy, Universe
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3
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anuttarasammyak
B Solar triangles
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8
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278
anorlunda
B How can we watch BHs collide in a finite time?
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18
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506
jbriggs444
B Star visible for longest time from Earth
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6
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235
Vanadium 50
B NASA’s InSight Mission Reveals Internal Structure of Mars
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134
Astronuc
B Do emission nebula glow because of ionised or excited electrons?
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4
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163
N
B Sun-Earth encounter
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15
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310
PeterDonis
B How does elongated shape from tidal force affect the light curve of a variable star?
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K
B Speed of light in outer space
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PeterDonis
B Biggest asteroid to pass Earth in 2021
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Astronuc
B Betelgeuse unusual dimming - what's up?
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Astronuc
B Light leaving Earth
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8
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523
PeroK
B The other side of the Moon
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13
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jim mcnamara
B Looking for Simulations of Exoplanets
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4
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393
Charlotte Bridge
B Seeing a half Moon - where is the Sun?
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590
T
B Extraterrestrial Object Orbits
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295
H
B Is the darkness in our solar system and/or galaxy (whichever it may be) an illusion?
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phinds
B Mass and Surface Gravity of a Dyson Sphere
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501
D
B Wonderful BH animation on APOD
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5
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345
Ibix
B Colonize cool white dwarfs
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7
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434
S
B Jupiter's pole storms - potential relation?
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246
S
B Need your advice how to start learning astronomy
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17
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682
S
B Is this a meteorite?
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6
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400
davenn
B Viewing distant celestial objects
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22
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russ_watters
B If the Earth did not rotate?
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31
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sophiecentaur
B Universal Total Eclipses
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21
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457
Vanadium 50
B Moon Shadow Question
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493
S
B Has there ever been a planet-planet eclipse (i.e., observed from Earth)?
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17
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T
B Does matter accumulate in Earth's gravity well?
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S
B Mars Landing, How instantaneous communication was possible
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10
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634
sophiecentaur
B What force keeps the planets orbiting normally?
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10
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688
weirdoguy
B "Snow" on comet 67P/Churyumov-Gerasimenko is actually stars
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4
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417
sophiecentaur
B Tidal locking for planets of K type (orange) dwarf stars
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2
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436
Cerenkov
B How the Earth's Magnetic field deflects the solar wind
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5
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396
J
B Gravitational waves
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298
Ibix
B Mass of solar wind
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12
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656
berkeman
B Planetary debris found in white dwarf atmospheres
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5
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399
Vanadium 50
B Density of the Asteroid Belt
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17
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556
sophiecentaur
B Dark Matter -- Is it possible that Dark Matter has Planck mass and Spin two?
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13
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mfb
B Trying to understand the differences between distant & local galaxies
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S
B Is the Universe spinning?
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9
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phinds
B Darkest Place on the Surface of the Earth
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518
B
B When does the perspective from the cockpit of a spaceship change?
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sophiecentaur
B The fastest spinning and possibly the youngest magnetar known
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300
lomidrevo
B Trace methane in Uranus and Neptune, condensing into diamonds
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2
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S
B Wow, what a photo!
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11
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Bruzote
B Creation and distribution of elements - looking for recommendations
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425
phinds
B What others systems are made of
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3
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phinds
B Jupiter and Saturn in one frame
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jtbell
B How much does Earth's gravity affect the gravity that we feel on the Lunar Surface?
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Charles Link
B Nature: "A massive white-dwarf merger product before final collapse"
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S
B Are subspaces of Hilbert space real?
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7
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W
B Can iron form via processes like the r- or s-process?
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S
B Where do the electrons go? (in stellar nuclear fusion)
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4
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C
B Snapped Cable Damages Arecibo Observatory Radio Telescope
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Drakkith
B Degeneracy pressure
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1
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K
B Question about things moving through outer space
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27
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V
B Question about Planck's Function
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hutchphd
B What causes orbits to be inclined?
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sophiecentaur
B Does Jupiter have an angular momentum problem?
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23
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Halc
B Question about the s-process and r-process in stellar evolution
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11
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K
B Nervous about James Webb Space Telescope?
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23
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russ_watters
B Pair Instability Supernovae & Electron Capture Supernovae
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2
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Drakkith
B Earth's Hubble velocity and measuring Hubble at large distances
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5
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429
N
B Help in explaining a question on gravity
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7
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sophiecentaur
B Star at black hole event horizon
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mfb
B The composition of interstellar dust
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11
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S
B Why is Carbon considered volatile?
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S
B NASA discovers water on the moon!
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H
B How does the observable Universe have meaning?
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phinds
B Some historic remarks on astrometry by Terence Tao
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DrClaude
B Phys.org - Carbon creation finding set to rock astrophysics
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1
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K
B Why is an inverse logarithmic scale chosen for the magnitudes of stars?
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sophiecentaur
B Redshift speed calculation
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2
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601
C
B There's Gold in Them Neutron Stars - or - Maybe Not
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W
B If a coronal ejection like this happened during a total eclipse ...
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11
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Quarkman1
B Measuring distance between two stars in a binary system
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10
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Buzz Bloom
B Is there a forum where people can share and discuss features on Mars?
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russ_watters
B What is the definition of a black hole?
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Ibix
B Are there any blue shifted galaxies name rc2?
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516
Vanadium 50
B Dark Substances
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19
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700
R
B By what process do different sized stars form?
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7
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875
S
B Popular physics - The Nebra disk
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4
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590
S
B Terraforming Mars
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14
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S
B Largest Moon With A Concave Orbit
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539
1977ub
B UV timelapse of the Sun in 4K, 52 min = 1 second
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3
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647
Drakkith
B Why is the momentum of a star equal to the momentum of a planet?
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8
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748
sophiecentaur
B Question re binary star systems & possible orbits
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11
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883
S
B What effect will SpaceX's 42K satellites have on astrononical viewing?
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3
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653
M
B The Coronal Heating Problem - The Hydrogen Fusion Core disappears?
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18
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Vanadium 50

Astronomy

Astronomy generally refers to the act of observing things (be that stars, galaxies or whatever) which, coupled with astrophysics, aims to understand those things for their own sake. The aim is to learn about the stars, galaxies or planets etc.

Astronomy, both observational and theoretical (and now also experimental!) is about what is going on in the universe that we can see now, or extrapolate to short times (~a billion years) in the past or future.

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