Astrophysics (index)about

planet

(round object orbiting a star that clears out its own orbital path)

The term planet is used for major objects orbiting stars other than binary-star companions. Detected extra-solar planets are so-far sufficiently large that there is no need to consider whether they qualify as "major". For the solar system, the IAU distinction is that the object be sufficiently massive that gravity draws it into a spherical shape and also massive enough to dynamically clear any planetesimals out of the path of its own orbit. This latter distinction (termed clearing the neighborhood) distinguishes it from a dwarf planet, and is what disqualified Pluto from being a "normal planet" (and incidentally disqualifies Ceres, once a "planet" as well), leaving the solar system with eight known planets out of the hundreds of thousands of objects known to orbit the Sun.

The object must also not be so massive as to trigger fusion and thus qualify as a star. The IAU considers an object above 13 Jupiter-masses to be a brown dwarf companion, that mass being an adopted estimate of the mass that could trigger deuterium-fusion.


(solar system,object type)
http://en.wikipedia.org/wiki/Planet

Referenced by:
abiotic oxygen
abundances
accretion
accretion rate
aerosols
albedo
Automated Planet Finder (APF)
appulse
asteroid
asteroid belt
astrobiology
atmosphere
atmosphere Formation
atmospheric model
atmospheric temperature profile
aurora
Black Widow Pulsar (B1957+20)
baroclinicity
basalt
Bayer designation
BepiColombo
biofluorescence
biosignature
black body (BB)
blended spectra
binary minor planet (BMP)
Bohr model
bow shock
Brunt-Väisälä frequency
bulk density
carbon (C)
carbonate-silicate cycle
carbon planet
Cassini
chemical equilibrium (CE)
celestial mechanics
centaur
chemodynamics
chirp
chondrite
CIG
circumbinary planet
circumplanetary disk
circumstellar disk
California-Kepler Survey (CKS)
cosmic microwave background (CMB)
carbon dioxide (CO2)
comet planet
core accretion model
coronagraph
COROT
corotation torque
corotation resonance (CR)
crustal magnetism
crustal plates
cryovolcano
Carl Sagan Institute (CSI)
dark matter
dead zone
debris disk
direct imaging
double-line spectroscopic binary
double transit
Drake equation
drogue chute
NASA Deep Space Network (NASA DSN)
dwarf planet
dynamical instability
dynamo
Earth
earthshine
exoplanet eclipse light curve
eclipse mapping
ecliptic
electron orbital
embryo barrier
ephemeris
epicycle
EPOXI
equatorial coordinate system
equilibrium condensation model
equilibrium temperature (Teq)
escape velocity (Ve)
Europa
exoearth
extra-solar planet
facula
51 Pegasi b (51 Peg b)
fixed star
Flamsteed designation
fractionation
Fulton gap
gas giant
gas planet
general circulation model (GCM)
geochemistry
gravitational instability (GI)
giant planet
Gemini Planet Imager (GPI)
gravitational instability model
gravitational lensing
gravity
gravity sounding
greenhouse effect
molecular hydrogen dissociation front (H2 dissociation front)
habitability
habitable zone (HZ)
Hadley cell
HARPS
HARPS-N
HCI
heliocentric system
Hobby-Eberly Telescope (HET)
Hill stability
hot Jupiter (HJ)
humidity
hydrology
International Astronomical Union (IAU)
ice giant
impact
inflated radii
infrared (IR)
internal gravity wave
Io
ionosphere
interplanetary medium (IPM)
irregular moon
isolation mass
isophote
isothermal core
intertropical convergence zone (ITCZ)
J1407
J2
epoch J2000.0
JUICE
Jupiter
Kapteyn's Star
K-type star (K)
Kelvin waves
Kepler Telescope
Keplerian disk
Keplerian orbit
Kepler radius
Kepler's laws
kilometer size barrier
Keck Planet Finder (KPF)
Keck Planet Imager and Characterizer (KPIC)
Kuiper Belt (K Belt)
Lagrange stability
Laplace-Lagrange secular theory
late heavy bombardment (LHB)
Lindblad torque
line broadening
liquid planet
long-period comet
Magellan Telescopes
magma ocean
magnetic anomaly
magnetic energy spectrum
magnetic field
magnetic induction
magnetometer
Mars
mass extinction
mass spectrometer
maximum iron fraction
M dwarf
Mercury
meridian
meridional flow
metallicity (Z)
meter size barrier
minor planet
MITgcm
MMRTG
moon
Moon formation
Minor Planet Center (MPC)
multiplicity fraction
NASA
N-body problem
N-body simulation
nebular hypothesis
Neptune
neutron scattering
NGTS
obliquity
occultation
occultation observations
opposition
orbital inclination
polycyclic aromatic hydrocarbon (PAH)
paleomagnetism
PALMS
partial ionization zone
particle spectrometer
phase curve
photoevaporation
Planet Nine
planetary embryo
planetary migration
planetary protection
planetesimal
planet formation
Planet Hunters (PH)
planetoid
planet structure
planet type
PLATO
Pluto
planetary nebula (PN)
polar cyclone
protoplanetary nebula (PPN)
precession
protected region
protoplanet
protoplanetary disk (PPD)
provisional designation
pulsar timing array (PTA)
vortensity (PV)
radar
radial velocity (RV)
radioactive heating
Rayleigh scattering
red dwarf
reducing atmosphere
regolith
retrograde hot Jupiter
radiative forcing (RF)
Laplace radius (rL)
Rossby number (Ro)
Roche limit
rocky planet
RODEO
Rossby waves
Rossby wave instability (RWI)
Saturn
scale height (H)
secondary eclipse
seismic waves
shepherd moon
Space Launch System (SLS)
solar system
SPACEWATCH
SPECULOOS
star formation (SF)
stellar radius determination
super-Earth
superionic ice
superrotating wind
surface brightness
surface gravity
surface reaction
surface temperature
survey-based designator
Sagittarius Window Eclipsing Extrasolar Planet Search (SWEEPS)
synodic period
Transiting Exoplanet Survey Satellite (TESS)
three dimensional model
tidal capture
tidal force
tidal locking
timescale (t)
Titius-Bode law
Telescopio Nazionale Galileo (TNG)
Terrestrial Planet Finder (TPF)
transit
transiting planet
transitional disk
transit spectroscopy
transmission spectroscopy
terrestrial time (TT)
transit timing variations (TTV)
Uranus
Venus
volatile material
vortex
vegetation red edge (VRE)
WASP
water-ice planet
water vapor planet
weathering
Yarkovsky effect
zonal flow
zone

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