Jeans escape

Jeans escape (countable and uncountable, plural Jeans escapes)

Named after English physicist Sir James Jeans (1877–1946), who is credited with calculating the rate of such atmospheric escape.

2014, Eugene F. Milone, William J. F. Wilson, Solar System Astrophysics, Springer, 2nd Edition, page 413,
As will be seem in Sects. 11.7.2.3 and 11.7.3.2, Jeans escape of H atoms from Venus is negligible compared to other, nonthermal mechanisms, whereas Jeans escape dominates the loss of H from Mars. On both planets, Jeans escape of O, O₂ and CO₂ is negligible.

where a≡m/2k_BT, n is the number density of particles and v is the magnitude of the velocity.

2017, Kevin Heng, Exoplanetary Atmospheres, Princeton University Press, page 213, The simplest model of Jeans escape [112], a mechanism named after the Englishman James H. Jeans, assumes that the constituent particles of the atmosphere may be described by a Maxwell-Boltzmann distribution, f_M=(a/π)ne, (13.6)

2021, Mark H. Thiemens, Mang Lin, 2: Discoveries of Mass Independent Isotope Effects in the Solar System, Ilya N. Bindeman, Andreas Pack (editors), Reviews in Mineralogy and Geochemistry, Volume 86: Triple Oxygen Isotope Geochemistry, Mineralogical Society of America, page 70,
The hydrogen is lost from the system by diffusion and Jeans escapes.

(planetology, astrophysics) A type of atmospheric escape in which a light gas atom or molecule (typically a helium atom or hydrogen molecule) gains sufficient momentum through collision with other molecules to escape the atmosphere (and gravitational pull) of a planet.


ciemna materia

ciemna materia (nominative singular)
ciemnej materii (genitive singular)
ciemnej materii (dative singular)
ciemną materię (accusative singular)
ciemną materią (instrumental singular)
ciemnej materii (locative singular)
ciemna materio (singular vocative)

Coordinate term: ciemna energia

(astronomy, astrophysics, cosmology, particle physics) dark matter (particles of matter that cannot be detected by their radiation)


ciemna energia

ciemna energia (nominative singular)
ciemnej energii (genitive singular)
ciemnej energii (dative singular)
ciemną energię (accusative singular)
ciemną energią (instrumental singular)
ciemnej energii (locative singular)
ciemna energio (singular vocative)

Coordinate term: ciemna materia

(astronomy, astrophysics, cosmology, particle physics) dark energy (hypothetical form of energy which, it is supposed, is spread uniformly throughout space and time and has anti-gravitational properties)


ბნელი ენერგია

ka-noun

ბნელი ენერგია • (bneli energia) (uncountable)

bneli energia (romanization)
ბნელი ენერგია (nominative singular)
ბნელმა ენერგიამ (ergative singular)
ბნელ ენერგიას (dative singular)
ბნელ ენერგიას (dative singular)
ბნელ ენერგიასაs) (dative singular)
ბნელ ენერგიასაsa) (dative singular)
ბნელი ენერგიის (genitive singular)
ბნელი ენერგიის (genitive singular)
ბნელი ენერგიისაs) (genitive singular)
ბნელი ენერგიისაsa) (genitive singular)
ბნელი ენერგიით (instrumental singular)
ბნელი ენერგიით (instrumental singular)
ბნელი ენერგიითაt) (instrumental singular)
ბნელი ენერგიითაta) (instrumental singular)
ბნელ ენერგიად (adverbial singular)
ბნელ ენერგიად (adverbial singular)
ბნელ ენერგიადაd) (adverbial singular)
ბნელ ენერგიადაda) (adverbial singular)
ბნელო ენერგიავ (singular vocative)
ბნელ ენერგიაზე (singular)
ბნელ ენერგიასთან (singular)
ბნელ ენერგიაში (singular)
ბნელ ენერგიასავით (singular)
ბნელი ენერგიისთვის (singular)
ბნელი ენერგიისებრ (singular)
ბნელი ენერგიისკენ (singular)
ბნელი ენერგიისგან (singular)
ბნელი ენერგიისადმი (singular)
ბნელი ენერგიიდან (singular)
ბნელი ენერგიითურთ (singular)
ბნელ ენერგიამდე (singular)


extremal black hole

en-noun

extremal black hole (plural extremal black holes)

(astrophysics, cosmology) A black hole with the minimum possible mass that is compatible with its charge and angular momentum.


Henyey track

pre-main-sequence star
pre-main-sequence star

Hertzsprung–Russell diagram
Hertzsprung–Russell diagram

(astrophysics) A path taken by pre-main-sequence stars with masses greater than 0.5 solar masses in the Hertzsprung–Russell diagram after the end of the Hayashi track.


Hayashi track

(astrophysics) A luminosity–temperature relationship obeyed by infant stars of less than 3 M☉ in the pre-main-sequence phase (PMS phase) of stellar evolution.


pre-main-sequence star

pre-main-sequence star (plural pre-main-sequence stars)

(astrophysics) A star in the stage when it has not yet reached the main sequence.


infant star

Perhaps thy sight is wandering far Throughout the kindled sky, In tracing every infant star Amid the lights on high,

1849, M. A. H., “The Dying Child”, in Echoes of Infant Voices, page 86:

Emitted radiation and a stellar wind flow from the infant star.

2006, Gregory L. Matloff, Deep Space Probes: To the Outer Solar System and Beyond, page 15:

In one discovery, Spitzer's infrared eyes have peered into the place where planets are born—the center of a dusty disc surrounding an infant star—and sped the icy ingredients of planets and comets.

2008, Paul Hutchins, The Secret Doorway: Beyond Imagination, page 61:

(astronomy, astrophysics) A newly formed star; a star that has just begun to sustain a fusion reaction.


LCDM

Alternative form: ΛCDM

“L.C.D.M. is being put through its paces by precision tests coming at it from every direction,” Dr. Turner said.

2024 April 4, Dennis Overbye, quoting Michael Turner, “A Tantalizing ‘Hint’ That Astronomers Got Dark Energy All Wrong”, in Thew New York Times:

lambda cold dark matter (model)
w:Lambda-CDM model

(astrophysics) Short for lambda cold dark matter (model).


one-way light time

one-way light time (countable and uncountable, plural one-way light times)

(astronomy, astrophysics) The amount of time required for light or a radio signal to travel between the Earth and a celestial body.


Forbush effect

Named after American physicist Scott Forbush.

coronal mass ejection
coronal mass ejection

(astrophysics) A rapid decrease in the observed galactic cosmic ray intensity following a coronal mass ejection.


spacetime metric

spacetime metric (plural spacetime metrics)

(astrophysics) Any method used to measure the geometry of the universe.


Yarkovsky effect

Named after Polish-Russian civil engineer Ivan Yarkovsky.

(astrophysics) A force acting on a rotating body in space caused by the anisotropic emission of thermal photons, which carry momentum.


σκοτεινή ενέργεια

head

σκοτεινή ενέργεια • (skoteiní enérgeia) f


eternal black hole

en-noun

eternal black hole (plural eternal black holes)

(astrophysics, cosmology) A theoretical idealization of a usually stationary black hole that has existed forever, rather than being formed from the collapse of some matter.


stellar black hole

stellar black hole (plural stellar black holes)

gravitational collapse
gravitational collapse

(astrophysics, cosmology) A black hole formed by the gravitational collapse of a star.


intermediate mass black hole

intermediate mass black hole (plural intermediate mass black holes)

(astrophysics, cosmology) A class of a black hole with a mass in the range of 102–105 solar masses.


micro black hole

micro black hole (plural micro black holes)

(astrophysics, cosmology) A hypothetical tiny black hole, of less than one solar mass, for which quantum mechanical effects play an important role.


BZ black hole

An initialism of Roger Blandford and Roman Znajek, theoretical astrophysicists.

The 'Blandford-Znajek' (BZ) black hole magnetospheric power extraction process was one of the first (1977) analytic attempts to define a general relativistic theory for axisymmetric, stationary, ideal-MHD, BH magnetospheres.

2002, Chang-Hwan Lee, Hŏn-yŏng Chang (editors), Current High-energy Emission Around Black Holes, page 36:

(astrophysics, cosmology) A rotating black hole that extracts energy from its rotation and magnetic fields to emit a jet of particles and radiation.


대폭발

Sino-Korean word from 大爆發, from 大 (“big”) + 爆發 (“explosion”).


atmospheric escape

en-noun

atmospheric escape (countable and uncountable, plural atmospheric escapes)

(astrophysics) The loss of planetary atmospheric gases to outer space.


triple-alpha process

triple-alpha process (plural triple-alpha processes)

triple-alpha processes (plural)
triple-α process (alternative)

(physics, astrophysics) A set of fusion reactions by which stars are thought to convert helium to carbon.

réaction triple alpha

group of nuclear reactions thought to occur in stars


mater tywyll

(astrophysics, cosmology, particle physics) dark matter


吸積盤

/ɕi⁵⁵ t͡ɕi⁵⁵ pʰän³⁵/

/kʰɐp̚⁵ t͡sɪk̚⁵ pʰuːn²¹/

/ɕi⁵⁵ t͡ɕi⁵⁵ pʰän³⁵/

/kʰɐp̚⁵ t͡sɪk̚⁵ pʰuːn²¹/


ბნელი მატერია

ka-noun

ბნელი მატერია • (bneli maṭeria) (uncountable)

bneli maṭeria (romanization)
ბნელი მატერია (nominative singular)
ბნელმა მატერიამ (ergative singular)
ბნელ მატერიას (dative singular)
ბნელ მატერიას (dative singular)
ბნელ მატერიასაs) (dative singular)
ბნელ მატერიასაsa) (dative singular)
ბნელი მატერიის (genitive singular)
ბნელი მატერიის (genitive singular)
ბნელი მატერიისაs) (genitive singular)
ბნელი მატერიისაsa) (genitive singular)
ბნელი მატერიით (instrumental singular)
ბნელი მატერიით (instrumental singular)
ბნელი მატერიითაt) (instrumental singular)
ბნელი მატერიითაta) (instrumental singular)
ბნელ მატერიად (adverbial singular)
ბნელ მატერიად (adverbial singular)
ბნელ მატერიადაd) (adverbial singular)
ბნელ მატერიადაda) (adverbial singular)
ბნელო მატერიავ (singular vocative)
ბნელ მატერიაზე (singular)
ბნელ მატერიასთან (singular)
ბნელ მატერიაში (singular)
ბნელ მატერიასავით (singular)
ბნელი მატერიისთვის (singular)
ბნელი მატერიისებრ (singular)
ბნელი მატერიისკენ (singular)
ბნელი მატერიისგან (singular)
ბნელი მატერიისადმი (singular)
ბნელი მატერიიდან (singular)
ბნელი მატერიითურთ (singular)
ბნელ მატერიამდე (singular)

(astronomy, astrophysics, particle physics, cosmology) dark matter


घटना क्षितिज

hi-noun

घटना क्षितिज • (ghaṭnā kṣitij) m

/ɡʱəʈ.nɑː kʂɪ.t̪ɪd͡ʒ/

[ɡʱɐʈ.näː‿kʃɪ.t̪ɪd͡ʒ]

From घटना (ghaṭnā, “event”) + क्षितिज (kṣitij, “horizon”).

hi:घटना क्षितिज


absolute horizon

en-noun

absolute horizon (plural absolute horizons)

(astrophysics) A boundary in spacetime, defined with respect to the external universe, inside which events cannot affect] an external observer.


apparent horizon

apparent horizon (plural apparent horizons)

(astrophysics) A surface that is the boundary between lightrays that are directed outwards and moving outwards and those directed outward but moving inward.


isolated horizon

isolated horizon (plural isolated horizons)

(astrophysics) In the context of black holes, a null hypersurface (a surface where light rays travel) that is in equilibrium with its surrounding environment.