protoplanetary disk
(PPD, disk, planetary disk, proto-planetary disk, preplanetary disk, PP disk)
(disk of dust and gas around a young star or protostar)
A protoplanetary disk (aka preplanetary disk,
either abbreviated PP disk or PPD) is a circumstellar disk,
consisting of dust and gas
orbiting a young star or protostar such as a T-Tauri star.
Radii can be as much as 1000 AU.
Such disks are thought to provide the material
for planet formation. The disks often develop
a flared torus shape due to a combination of heat
and radiation pressure from the disk's host star.
They can last several million years, evolving
through accretion, outflows,
photoevaporation, and/or condensation into larger
bodies, small to large (planetesimals or planets).
Though the lifetime is millions of years, this is short enough that
it has been considered as a possible limiting factor regarding the type
of planets emerging, e.g., how large a gas planet
can grow before the disk gas is gone.
The term proplyd is an abbreviation of protoplanetary disk,
sometimes used generally but often specifically for some types of
observed objects interpreted as protoplanetary
disks: as glowing objects presumed ionized by the
host star or another star and/or as shapes seen blocking light from
behind. Star-forming regions typically include hot stars that produce
ionizing radiation. The disks may be seen in the ultraviolet
due to the ionization, or in the infrared due to
thermal emission from the disk's dust. Direct imaging of
such disks have been carried out by the HST, ALMA, and
Subaru Telescope.
The dust in a protoplanetary disk necessarily varies
in size (i.e., some of it grows) if solid objects are forming.
The dust inherited from the star-forming region is presumed to be
up to micron sized. Some information about the location of different
sizes can be gleaned from resolving the disk at different wavelengths:
grains tend to emit thermal radiation most efficiently
at a wavelength on the order of their diameter. Disks
generally show fewer larger grains further out which
matches the notion that the effects of radiation pressure
on dust grains are significant.
(disk type,object type)
Further reading:
https://en.wikipedia.org/wiki/Protoplanetary_disk
https://en.wikipedia.org/wiki/Proplyd
https://dictionary.obspm.fr/index.php?formSearchTextfield=protoplanetary+disk&showAll=1
https://sites.pitt.edu/~cejones/GeoImages/0PlanetaryFormation/PlanetaryFmn/0PlanetaryFormation.html
https://public.nrao.edu/gallery/twenty-protoplanetary-disks-imaged-by-alma/
https://www.daviddarling.info/encyclopedia/P/protoplandisk.html
https://jila.colorado.edu/~pja/araa.html
https://ui.adsabs.harvard.edu/abs/2011ARA%26A..49..195A/abstract
Referenced by pages:
1.3-mm observation
AB Aurigae (AB Aur)
accretion
accretion disk
atmosphere formation
baroclinicity
barrier
Bondi radius
bouncing barrier
carbon (C)
carbon dioxide (CO2)
carbon monoxide (CO)
carbon planet
circumstellar disk
CO ladder
computational astrophysics
core accretion model
corotation resonance
cosmic dust
debris disk
direct imaging
disk
disk gap
DSHARP
dust trap
dynamical friction
dynamical instability
dynamo
electrostatic barrier
Elias 2-27
fragmentation barrier
free-floating planet (FFP)
FU Orionis star (FUor)
gas flow
giant planet
giant planet formation
giant star
grand tack hypothesis
gravitational instability (GI)
gravitational instability model
HD 163296
HD 169142
heating
HL Tau
hydrogen cyanide (HCN)
hydrogen deuteride (HD)
hydrostatic equilibrium
I band
ice
inertial wave
Infrared Space Observatory (ISO)
isolation mass
Kelvin-Helmholtz instability (KHI)
kilometer size barrier
Lindblad resonance
line tomography
MAPS
meter size barrier
millimeter astronomy
morphology
MWC 758
nebular hypothesis
Orion Disks
passive dust
PDS 70
pebble accretion
photoevaporation
planet formation
planetary embryo
planetary migration
polarimetry
protoplanetary nebula (PPN)
radial drift
radial mixing
radial-drift barrier
RODEO
Rossby wave instability (RWI)
Rossby waves
RXJ1615
snow line
solar nebula
speckle suppression
spiral density wave
stellar age determination
streaming instability
striae
T-Tauri star (TTS)
Toomre Q parameter (Q)
TW Hydrae (TW Hya)
vortensity
Index