Astrophysics (Index)About

extra-solar planet

(exoplanet)
(planet not in the solar system)

An extra-solar planet (or exoplanet) is a planet outside the solar system, e.g., orbiting another star. The first confirmed detection of an exoplanet was in 1992 (PSR 1257+12 A) and the first around a main sequence star (51 Pegasi) in 1995. As of 12/2019, 4100+ planets around 3000+ stars are known.

Detection methods:

A number of methods have been contemplated for future technology:

The RV method reveals the relative masses of the host star and planet, and a transit reveals their relative radius, so the density of a planet can be estimated if the planet can be observed by both methods, limited by the accuracy of these estimates for the star. For this reason, follow-ups are carried out to detect it by both if that possibility looks promising, leading to attempts to predict transit times from RV data, especially if the orbit is long (i.e., transits are infrequent) and available telescope time is limited.

Some terms used to indicate planets of various characteristics, particularly their rough size:

Terms like super Neptune are also used to indicate a Neptune-like composition. Using a criteria based on mass, brown dwarfs are the next step up from planets, for objects of more than 13 Jupiter masses. However sometimes other star- or planet-like characteristics are taken as more important than the mass criteria.

(These terms present a writing style issue: whether Jupiter, Earth, and Neptune should be capitalized, e.g., in hot Jupiter or in Jupiters. I find no rules, and only partial consistency, and have elected to follow the style I find most common.)

The spacecraft Kepler surveyed a portion of the sky for exoplanets, detecting (including K2) 5500 not-yet-eliminated candidates, of which 2700 have been confirmed to be planets as of 12/2019.

Projected population statistics based upon surveys:

The commonly used method of referring to exoplanets is somewhat-modeled after the system for individual members of binary stars. The first planet discovered is specified by the star's name followed by "b", the next, "c". For example HD 80606 b is a planet orbiting the star HD 80606. If two or more are discovered simultaneously, they are lettered outward from the innermost.


(planets)
Further reading:
http://en.wikipedia.org/wiki/Exoplanet
https://exoplanetarchive.ipac.caltech.edu/
https://exoplanetarchive.ipac.caltech.edu/docs/counts_detail.html
http://exoplanets.org/

Referenced by pages:
abiotic oxygen
Alpha Centauri
Automated Planet Finder (APF)
ARIEL
astrometry
astronomical quantities
atmospheric escape
atmospheric model
atmospheric temperature profile
AU Microscopii (AU Mic)
aurora
Black Widow Pulsar (B1957+20)
Bayer designation
biofluorescence
biosignature
blended spectra
Beta Pictoris b (β Pic b)
bulk silicate ea­rth (BSE)
carbonate-silicate cycle
candidate companion (CC)
CHEOPS
circumbinary planet
circumplanetary disk
California-Kepler Survey (CKS)
carbon dioxide (CO2)
color-color diagram (CCD)
comet planet
core accretion model
coronagraph
CRIRES
crustal plates
Carl Sagan Institute (CSI)
Darwin
dead zone
demographics
direct imaging
double-line spectroscopic binary (SB2)
double star
double transit
Earth
Earth analog
earthshine
eccentricity (e)
exoplanet eclipse light curve
eclipse mapping
EPOXI
equilibrium temperature (Teq)
European Southern Observatory Very Large Telescope (ESO VLT)
extreme adaptive optics (ExAO)
ExoCTK
exoearth
ExoFOP
exosatellite
Exo-S
F-type star (F)
FINESSE
51 Eridani b
51 Pegasi b (51 Peg b)
Flamsteed designation
47 Tucanae (47 Tuc)
forward model
Fulton gap
gas giant
gas planet
G-CLEF
general circulation model (GCM)
Gemini Observatory
geochemistry
geosignature
giant planet
giant planet formation
Gliese-Jahreiss Catalog (GJ)
GJ 1132 b
GJ 1214 b
Gliese 436 b (GJ 436 b)
Gemini Planet Imager (GPI)
gravitational instability model
greenhouse effect
HabEx
habitability
HARPS
HARPS-N
HATNet
HCI
HD 133131
helium 1083 nm line
hot Jupiter (HJ)
HR 8799
humidity
hydrology
insolation
internal gravity wave
isolation mass
intertropical convergence zone (ITCZ)
Jupiter
K-type star (K)
Keck Observatory
Kelvin waves
Kepler Telescope
Kepler-1625b
Kepler-16b
Kepler-186f
Kepler-452b
Kepler radius
Kozai mechanism
Keck Planet Finder (KPF)
Keck Planet Imager and Characterizer (KPIC)
Lacaille 9352
Lagrangian point
Laplace-Lagrange secular theory
lightkurve
magma ocean
MASCARA
mass extinction
maximum iron fraction
M dwarf
mega-Earth
gravitational microlensing
minimum mass (m sin i)
MOA
molecular handedness
MUSCLES
NANOGrav
natural astronomical telescopes
Neptune
New Worlds Mission
NIRPS
numerical weather prediction (NWP)
occultation
OGLE
one dimensional climate model
orbital inclination
orbit plot
Origins Space Telescope (OST)
Other Worlds Laboratory (OWL)
PanCET
perturbation theory
phase angle
phase curve
photoevaporation
photometry
planet
planetary science
planet demographics
planet formation
planet type
PLATO
projected separation
Proxima b
PSF fitting
PSR 1257+12
Qatar Exoplanet Survey (QES)
radial velocity (RV)
rare designator prefixes
Rayleigh scattering
red dwarf
red noise
redshift (z)
retrieval
retrograde orbit
ring system
ROCKE-3D
rocky planet
Rossiter-McLaughlin effect (RM effect)
rotation period
radial velocity method
Sloan Digital Sky Survey (SDSS)
secondary eclipse
silicate
speckle suppression
spectroscopic binary (SB)
SPECULOOS
SPHERE
SPHEREx
SPIRou
star count
starshade
stellar flare
stellar radius determination
Subaru Telescope
subgrid-scale physics
subsatellite
sunspot
super-Earth
superrotating wind
survey-based designator
Sagittarius Window Eclipsing Extrasolar Planet Search (SWEEPS)
Transiting Exoplanet Survey Satellite (TESS)
Tucana Horologium association (THA)
timescale (t)
TOI 700 d
Terrestrial Planet Finder (TPF)
transient astronomy
transit
transiting planet
transit method
transit spectroscopy
transmission spectroscopy
TRAPPIST
TRAPPIST-1
Trans-Atlantic Exoplanet Survey (TrES)
transit timing variations (TTV)
TW Hydrae (TW Hya)
ultraviolet (UV)
Ultimate Spitzer Phase Curve Survey (USPCS)
vegetation red edge (VRE)
water-ice planet
water lines
water vapor planet
water world
James Webb Space Telescope (JWST)
Roman Space Telescope (RST)
XO Project

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