Hellings and Downs curve

Hellings and Downs curve (plural Hellings and Downs curves)

Named after R.W. Hellings and G.S. Downs, who first calculated it.

(astronomy) A graph of the expected correlation of timing effects on pulsars due to cosmological gravitational waves, as a function of angle of separation of the pulsars.


SMBHB

supermassive black hole binary
supermassive black hole binary#English

supermassive black hole
supermassive black hole

(astronomy) Abbreviation of supermassive black hole binary. (a pair of supermassive black holes at the centre of two galaxies that have merged)


cosmic web

The observations reveal that an ancient cluster of galaxies about 12bn light years away in the constellation of Aquarius are linked together by a network of faint gas filaments. The existence of the cosmic web is central to current theories of how galaxies first formed following the big bang, but until now evidence for it had remained largely circumstantial.

2019 October 3, Hannah Devlin, “Scientists observe mysterious cosmic web directly for first time”, in The Guardian, →ISSN:

(astronomy) A vast foam-like structure of galaxy clusters, superclusters, sheets, walls, and filaments, separated by immense voids.


solar storm

Life on Earth has developed over billions of years, largely unaffected by the solar storms that wash over our planet from time to time. But in the last 200 years, humans have become increasingly reliant on technologies that are vulnerable to these geomagnetic events. […] Solar storms drive currents of millions of amps through the electrically conductive upper layer of our atmosphere (known as the ionosphere). These currents, which can fluctuate rapidly, drive powerful magnetic disturbances at the Earth's surface that in turn induce electrical currents in the planet's crust.

2023 November 15, Prof. Jim Wild, “This train was delayed because of bad weather in space”, in RAIL, number 996, page 30:

(astronomy) an electromagnetic storm on the photosphere of the Sun


GZK

GZK cutoff; GZK limit; GZK horizon; GZK mechanism

(astronomy, attributive) Initialism of Greisen–Zatsepin–Kuzmin.


Oh-My-God particle

en-noun

Oh-My-God particle (plural Oh-My-God particles)

(astronomy, physics) An ultra-high-energy cosmic ray detected in 1991, of uncertain nature, which exceeds the GZK limit; the highest energy particle ever discovered.


Cepheid

From Latin Cephei + -id, from Latin Cepheus, from Ancient Greek Κηφεύς (Kēpheús).

suffix

Latin <i class="Latn mention" lang="la">Cephei</i>


Alcor

(astronomy) A binary star system in the constellation of Ursa Major.


exaparsec

(astronomy) An astronomical unit of distance equal to 10¹⁸ parsecs.


zettaparsec

(astronomy) An astronomical unit of distance equal to 10²¹ parsecs.


ronnaparsec

(astronomy) An astronomical unit of distance equal to 10²⁷ parsecs.


quettaparsec

(astronomy) An astronomical unit of distance equal to 10³⁰ parsecs.


tiger stripes

A plume, consisting of many individual jets, expels subsurface material originating from the ocean from four parallel fractures, the so-called tiger stripes, located in the south polar terrain.

2023 April, N. Khawaja, T. R. O’Sullivan, F. Klenner, L.H. Sanchez, J. Hillier, “Discriminating Aromatic Parent Compounds and Their Derivative Isomers in Ice Grains From Enceladus and Europa Using a Laboratory Analogue for Spaceborne Mass Spectrometers”, in Earth and Space Science, volume 10, number 4, →DOI:

This moon is the main source of material for Saturn’s E ring, due to the 100 km sized plumes emanating from its south pole, ejecting water ice and water vapour [54,62]. This is released from aligned vent structures, named tiger stripes, that are fed by a subsurface ocean that experiences ongoing hydrothermal interaction with a silicate core as shown in Figure 1 [63].

2023, Francisco Calapez, Rodrigo Dias, Rute Cesário, Diogo Gonçalves, Bruno Pedras, et al., “Spectroscopic Detection of Biosignatures in Natural Ice Samples as a Proxy for Icy Moons”, in Life, volume 13, number 2, Basel, →DOI, page 478:

(astronomy) A series of four parallel depressions on the surface of Enceladus, a moon orbiting Saturn.


Jeans escape

en-noun

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.


Ho'oleilana

Translingual: Ho'oleilana

Hawaiian: Hoʻoleilana

/ˌhəʊ.əʊleɪˈlɑːnə/

From Hawaiian hoʻoleilei ka lana (“sent sounds of awakening”). Coined by R. Brent Tully, Cullan Howlett, and Daniel Pomarède in 2023; see quotation below.

coinage

In any event, this apparent ring structure at a distance of ∼250 Mpc from us is one of the largest structures observed in the nearby Universe to date and links together a number of hitherto disconnected components of our cosmic neighborhood. We name this remarkable structure "Ho'oleilana."
fn: "Sent murmurs of awakening" from the Hawaiian Kumulipo creation chant: Ho'oleilei ka lana a ka Po uliuli, "From deep darkness came murmurs of awakening."

2023, R. Brent Tully, Cullan Howlett, Daniel Pomarède, “Ho'oleilana: An Individual Baryon Acoustic Oscillation?”, in The Astrophysical Journal, volume 954, number 2:

baryon acoustic oscillation
baryon acoustic oscillation#English

(astronomy, cosmology) Ho'oleilana A structure in local Universe; An assembly of superclusters and voids, forming a spherical assemblage of matter with a central peak, roughly 1-billion-lightyears across, located next to, but not containing, Laniakea, our local supercluster where the Earth is contained within. Thought to be a baryon acoustic oscillation (“BAO”), the first such discovered, and the nearest such found.


Greisen-Zatsepin-Kuzmin limit

the Greisen-Zatsepin-Kuzmin limit (canonical)

From the surnames of the three physicists who proposed this limitation on the long distance travel of energetic particles. From Greisen + Zatsepin + Kuzmin. Named after the American physicist Kenneth Greisen, and the Soviet physicists Georgiy Zatsepin, and Vadim Kuzmin. The Soviet and the American teams each discovered the limit separately in the 1960s, being independently computed in 1966.

intergalactic medium
intergalactic medium

(astronomy, physics) A theoretical upper limit on the energy of cosmic ray protons travelling from other galaxies through the intergalactic medium to the Milky Way.

en:Georgiy Zatsepin
en:Kenneth Greisen
en:Vadim Kuzmin (physicist)

OMG particle

the most energetic EECR discovered so far

zevatron

placeholder name for that which accelerates particles above this limit


LFBOT

luminous fast blue optical transient#English

(astronomy) Abbreviation of luminous fast blue optical transient.


EECR

extremely energetic cosmic ray
extremely energetic cosmic ray#English

extreme-energy cosmic ray
extreme-energy cosmic ray#English

(astronomy, physics) Initialism of extremely energetic cosmic ray/extreme-energy cosmic ray.: A cosmic ray particle exceeding the GZK limit.


Alrakis

From Arabic الرَّاقِص (ar-rāqiṣ, “the dancer”).

der

(astronomy) Mu Draconis A, a star in the constellation of Draco.


Big Banger

Steady Staters were convinced that Big Bangers did not know what they were talking about, and vice versa.

2001, Rem Blanchard Edwards, What Caused the Big Bang?, page 66:


steady stater

(cosmology) A believer in the steady state theory.


overmassive

en-adj

overmassive (comparative more overmassive, superlative most overmassive)

more overmassive (comparative)
most overmassive (superlative)

(astronomy) Of a star: having a greater mass than is typical for its type.


Swift-Tuttle

Independently discovered by American astronomers Lewis A. Swift (1820–1913), on 16 July 1862, and Horace Parnell Tuttle (1837–1923), on 19 July 1862.

Horace Parnell Tuttle
Lewis A. Swift
Swift-Tuttle


light time

en-noun

light time (countable and uncountable, plural light times)

(astronomy) The time taken for light to travel between two locations, especially celestial bodies.


Seyfert galaxy

Seyfert galaxy (plural Seyfert galaxies)

Named after Carl Seyfert, who first described this class in 1943.

(astronomy) A kind of galaxy having quasar-like nuclei.


head

my very excellent mother just served us nine pizzas

(astronomy, slightly dated, mnemonic) Used to remember the order and names of the (then) nine planets of the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto.

my very educated mother just served us nine pumpkins


photoevaporate

en-verb

photoevaporate (third-person singular simple present photoevaporates, present participle photoevaporating, simple past and past participle photoevaporated)

photoevaporates (present singular third-person)
photoevaporating (participle present)
photoevaporated (participle past)
photoevaporated (past)

High-mass stars rapidly (~ 10⁵ yr) photoevaporate the outer (r > 5 AU) portions of their disks […]

2006 June 8, Sabine Richling, David Hollenbach, Harold W. Yorke, “Destruction of protoplanetary disks by photoevaporation”, in Hubert Klahr, Wolfgang Brandner, editor, Planet Formation: Theory, Observations, and Experiments, Cambridge University Press, page 40:

(astronomy, of energetic radiation or its source) To ionise gas and cause it to disperse.


exoasteroid

(astronomy) An asteroid outside the Solar System.


TLP

(astronomy) Initialism of Transient Lunar Phenomenon.


exoasteroid belt

multiexoplanetary system
multiexoplanetary system

(astronomy) The exoasteroid belt, region of exoasteroids in an orbital plane of an exoplanet, or multiexoplanetary system, outside the Solar System.


Vishakha

(astronomy) the 14th (later 16th) lunar asterism (figured by a decorated arch and containing four or originally two stars under the regency of a dual divinity, इन्द्र and अग्नि ; it is probably to be connected with the quadrangle of stars ι, α, β, γ Librae.


circumplanetary disk

en-noun

circumplanetary disk (plural circumplanetary disks)

(astronomy) A torus-, pancake- or ring-shaped accumulation of matter in orbit around a planet.


sun-like

en-adj

sun-like (comparative more sun-like, superlative most sun-like)

more sun-like (comparative)
most sun-like (superlative)


SAURON

Backronym inspired by the type of radio object it falls under, the ORCs, and the master of orcs in Tolkien literature, Sauron. Coined in 2022 by the discovery team made up of researchers from MeerKAT, South African Radio Astronomy Observatory (SARAO), and University of the Western Cape (UWC).

(astronomy) Acronym of steep and uneven ring of non-thermal radiation, an ORC (“odd radio circle”) found in the southern sky.

en:MeerKAT
en:University of the Western Cape


lookback time

(astronomy, cosmology) The amount of time elapsed between the moment that light is detected on Earth and the moment it was originally emitted by the source.


Baker-Nunn camera

en-noun

Baker-Nunn camera (plural Baker-Nunn cameras)

(astronomy) A device like a Schmidt camera but having a small triplet corrector lens closer to the focus of the camera.


crossing time

(astronomy, cosmology) The amount of time required for a star or galaxy to make a crossing from one side of a gravitationally bound cluster to the other.


dynamical time

dynamical time (countable and uncountable, plural dynamical times)

(astronomy, cosmology) A time scale used to calculate the orbital motions of objects within the Solar System.


deuterium bottleneck

(cosmology) A critical stage in the early universe's nucleosynthesis process, in which the temperature was high enough for many photons to have energy greater than the binding energy of deuterium; therefore any deuterium that was formed was immediately destroyed.


sunview

Fig. 3. Sunview of the Earth at the middle of the Transit of 1882 .

1875, Richard A. Proctor, “Past and Coming transits and Arctic Explorations”, in James Samuelson, Henry Lawson, William Sweetland Dallas, editor, The Popular Science Review, page 274:

Figure 9. The New Acropolis Museum, Athens (M. Nicoletti - L. Passarelli) - view from the Acropolist, general view, solar scheme, sunviews of the “eye”, the Parthenon space

2014, Eduardo Maldonado, Simos Yannas, Environmentally Friendly Cities, page 18:

(astronomy, obsolete, rare) A view or prospect as if it were from the sun.


dark moon

(astronomy) The last visible crescent of a waning moon.


smuggler's moon

So named because a smuggler at nighttime can pass by undetected or unnoticed due to the dim light.

On this hot, humid night, the moon, a smuggler's moon, rose like a giant orange ball from the swamp.

1979, Albert Goldman, Grass Roots: Marijuana in America Today, page 184:

The mountain was lit by a smuggler's moon by 10 p.m. and it was easier now to walk down.

1982, The Himalayan Journal - Volume 38, page 67:

A smuggler's moon, so they called it here on the Romney Marsh, where the southern shore of England teased the coast of France. Enough light to make it easy to slip over the sand with uncustomed tea and brandy, but too little to give His Majesty's riding officers a clear shot at one's back.

1991, Christina Skye, The Black Rose, page 15:

(astronomy) A moon that emits only dim light.

It was that one time of the month when the moon turned coward and its back was all one could see. A smuggler's moon.

Above him, a thin cloud moved across the bright sliver of the moon. A smuggler's moon.

1994, Sibylle Garrett, Knight's Corner, page 162:

On Wednesday evening (26th) the five bars and pubs on St Mary's were almost empty as regulars made the most of a smuggler's moon to return to the wreck in darkness to see what they could find.

"It's so dark," she said. "I can only see a few stars." "A smuggler's moon."

2001, Cassie Miles, Undercover Protector, page 233:


main-sequence star

main-sequence star (plural main-sequence stars)

Hertzsprung-Russell diagram
Hertzsprung-Russell diagram

(astronomy) A star which falls within the main sequence on a Hertzsprung-Russell diagram, being the most common type of star in the universe.


chemically peculiar star

chemically peculiar star (plural chemically peculiar stars)

(astronomy) A main-sequence star with an unusually high abundance of metal.


galactic disc

(astronomy) A thin, circular distribution of stars and stellar material in a spiral or lenticular galaxy which orbits around the galactic center.


super-Neptune

(astronomy) An exoplanet with more mass than Neptune (around 17 M_E) but with less mass than Saturn (around 95 M_E).


super-puff

(astronomy) An exoplanet with greater diameter than Neptune with a mass only a few times that of Earth, giving it a very low density.


zombie star

(astronomy) A hypothetical remnant star left behind by a type Iax supernova, which only partially dispersed the progenitor star.


VLA

(astronomy) Abbreviation of Very Large Array. (the large interferometre in New Mexico used for radio astronomy)


round-trip light time

round-trip light time (countable and uncountable, plural round-trip light times)

(cosmology) The amount of time required for an electromagnetic signal to travel from Earth to a spacecraft or another celestial body within the Solar System and then return.


time of pericenter passage

(astronomy) A time at which an orbiting body passes through the pericenter, closest to the central body.


extremal black hole

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.


periselenium

From peri- + seleno- + -ium, Latin form of -ion.

Hence, the Earth gravity allows the decrease of the particle energy from zero to a negative value and its capture by the moon to an elliptical orbit, e.g., with a periselenium of ~2,000 km and a high aposelenium of ~70,000h km.

2004, Science and Technology Series, volume 108, American Astronautical Society, page 162:

(astronomy) The point of a body's elliptical orbit about the moon's centre of mass where the distance between the body and the centre of mass is at its minimum.


Zoozve

LL-Q1860 (eng)-Flame, not lame-Zoozve.wav

Accidentally coined by Alex Foster by misreading the asteroid's provisional designation "2002VE". Later requested to be the official name by Brian A. Skiff (the discoverer of the asteroid) to the WGSBN (Working Group Small Bodies Nomenclature), and approved February 5, 2024.

(astronomy) A temporary quasi-satellite of the planet Venus.


Crab Nebula

(astronomy) A supernova remnant and pulsar wind nebula in the constellation of Taurus.


Gomez's Hamburger

Named for its discoverer, Chilean astronomer and astrophotographer Arturo Gómez, and for its resemblance to a hamburger (its protoplanetary disk the dark “burger” and the far sparser starlight-illuminated dust on either side the light “buns”) when viewed edge-on from Earth.

(astronomy) A young A0III-type star with an apparent magnitude of +14.4 in the constellation Sagittarius at a distance of 250 ±50 parsecs from Earth.

Hamburguesa de Gómez

A0III-type star (V +14.4) in Sagittarius, 250 ±50 pc from Earth


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.


Eurycleia

(astronomy) A crater on the moon Tethys.


Schmidt corrector plate

Schmidt corrector plate (plural Schmidt corrector plates)

The lens was invented by Bernhard Schmidt in 1931.

Schmidt-Cassegrain telescope
Schmidt-Cassegrain telescope

(astronomy) An aspheric lens that corrects the spherical aberration introduced by the spherical primary mirror of the Schmidt telescope or Schmidt-Cassegrain telescope.


DESI

While combining data sets is tricky, and these are early results from DESI, the possible evidence that dark energy is not constant is the best news I have heard since cosmic acceleration was firmly established 20-plus years ago.

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

Dark Energy Spectroscopic Instrument
w:Dark Energy Spectroscopic Instrument

(astronomy) Acronym of Dark Energy Spectroscopic Instrument.


cosmic time

cosmic time (countable and uncountable, plural cosmic times)

(physics, cosmology) The measure of time by a physical clock with zero peculiar velocity in the absence of matter overdensities or underdensities; commonly used in the Big Bang models of physical cosmology.


Kronian

The figure compares the Jovian and Kronian magnetosphere-ionosphere coupling currents.

(astronomy) Related to the planet Saturn.


equinoctial time

equinoctial time (countable and uncountable, plural equinoctial times)

(astronomy) A year from the moment when the mean sun is positioned at the mean vernal equinoctial point.


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.


revisit time

revisit time (countable and uncountable, plural revisit times)

(astronomy) The amount of time elapsed between observations of the same ground point on Earth by a satellite.


local mean sidereal time

local mean sidereal time (countable and uncountable, plural local mean sidereal times)

(astronomy, time) A time scale indicating the immediate position of an observer relative to the stars, calculated by adding the longitude of the observer, measured east of Greenwich, to Greenwich sidereal time (GMST).


Terrestrial Time

(astronomy, time) A modern astronomical time standard defined by the International Astronomical Union, primarily for time-measurements of astronomical observations made from the surface of the Earth.


Great Filter

(astronomy) A barrier which prevents intelligent life from developing to a level where it can be detected across interstellar distances.

While there are plenty of potential explanations and counterarguments for the Fermi paradox, one that has grabbed a lot of attention is known as the Great Filter - the idea that there is some sort of filter that prevents a civilization from becoming advanced enough to traverse the galaxy.

2024 March 18, “Exploring the SCP Foundation: SCP-3426 - Reckoner” (0:50 from the start), in The Exploring Series, archived from the original on 2024-03-30:

(astronomy) The hypothesis that such a barrier exists.


magnetic local time

magnetic local time (countable and uncountable, plural magnetic local times)

(astronomy, time) A parameter measuring the time at a location on the surface of the Earth based on the Earth's magnetic field, often used to describe a position in near-earth space.


local sidereal time

local sidereal time (countable and uncountable, plural local sidereal times)

(astronomy, time) A sidereal time of a specific location on the Earth, depending on the longitude of the point.


near-Earth

(astronomy) Positioned or occurring close to the Earth.

(astronomy) Of an asteroid or comet, one that nearly intersects that of the Earth.


mean sidereal time

mean sidereal time (countable and uncountable, plural mean sidereal times)

(astronomy, time) The hour angle between the meridian of Greenwich and the mean equinox of a specific date at Universal Time.


geomagnetic storm

geomagnetic storm (plural geomagnetic storms)

(astronomy) A temporary disturbance of the Earth's magnetosphere caused by a solar wind shockwave.


polar axis

(astronomy) Of an equatorial mounting, the axis of rotation that is positioned parallel to the axis of the Earth, allowing a telescope to be turned in an hour angle or a right ascension.


convective mixing time

convective mixing time (countable and uncountable, plural convective mixing times)

(physics, astronomy) The amount of time it takes for mixing to occur by convection.


Rossiter-McLaughlin effect

Rossiter-McLaughlin effect (plural Rossiter-McLaughlin effects)

Named after Richard Alfred Rossiter and Dean Benjamin McLaughlin.

(astronomy) A spectroscopic phenomenon observed when an object moves across the face of a rotating star which is seen to undergo a redshift anomaly caused by the obscuration of different parts of its disk.

Dean Benjamin McLaughlin
Richard Alfred Rossiter


Wilson-Bappu effect

Named after Olin Chaddock Wilson and Vainu Bappu.

absolute visual magnitude
absolute magnitude

(astronomy, spectroscopy) The correlation between the measured width of the calcium II K emission line and the absolute visual magnitude of a star.


orange dwarf

(astronomy) A small orange star of the main sequence.


Adrastean

(astronomy) Of or relating to the Jovian moon named for Adrasteia.


second contact

second contact (countable and uncountable, plural second contacts)

(astronomy) The moment, during an eclipse or transit, when the smaller body is entirely inside the larger body, moving further inward, also known as interior ingress.


third contact

third contact (countable and uncountable, plural third contacts)

(astronomy) The moment, during an eclipse or transit, when the smaller body is entirely inside the larger body, moving outward, also known as interior egress.


fourth contact

fourth contact (countable and uncountable, plural fourth contacts)

(astronomy) The moment, during an eclipse or transit, when the smaller body is entirely outside the larger body, moving outward, also known as exterior egress.


Kaffaljidhma

Borrowed from Arabic الكَفّ الجَذْمَاء (al-kaff al-jaḏmāʔ, literally “the cut-short hand”).

bor+

الكَفّ الجَذْمَاء

(astronomy) Gamma Ceti, a triple star system in the equatorial constellation of Cetus.


dark-zilla

From dark + -zilla. From being the dark sector version of WIMPzilla. Coined by Katherine Freese and Martin Wolfgang Winkler in 2023.

(physics, cosmology) Theoretical extremely massive dark matter particle, orders of magnitude greater than 10¹⁰ GeV (gigaelectronvolts), thought to be generated by a vacuum phase change event, where rapidly colliding collapsing bubbles of false vacuum generate the particles in energetic collisions.


multiversally

en-adv

multiversally (comparative more multiversally, superlative most multiversally)

more multiversally (comparative)
most multiversally (superlative)

The mission is critical but need not be rushed. The storm has been brewing for several weeks, and will not reach multiversally devastating proportions for a few months.

1980, TSR, Frank Mentzer, Dungeons & Dragons 1st Edition: The Immortal Storm Complete, Rainbow Communications, →ISBN, page 25:

I have no knowledge of any Project 616,” I say. "I can only conjecture. Let me think.. .'616' is the multiversally agreed designature of this Universe.”

2014, Dan Abnett, Rocket Raccoon and Groot: Steal the Galaxy!: An Original Novel of the Marvel Universe, Marvel Worldwide, →ISBN, page 148:

Our answer: Well, duh! Multiversally, baby.

2016, Linda Varsell Smith, Star Stuff: A Soul-Splinter Experiences the Cosmos, Rainbow Communications, →ISBN, page 25:

(rare, physics, science fiction, fantasy, cosmology) In a multiversal manner.


subflare

We have included in our program of measurement examples of brightenings for which the maximum intensity did not exceed twice the intensity of the undisturbed Ha background (0.64 times that of the continuous spectrum). These small brightenings should probably be thought of as “‘subflares” or flares of importance 1— or less.

1953, Gerard P. Kuiper, The Sun, The University of Chicago Press, page 701:

It was found that large flares were reliably detected by small subflares only occasionally.

1957, Hearings 1957-05-01, Superintendent of Government Documents, page 54:

They occur more often, are intenser and last longer at metre wavelengths than at shorter wavelengths. In the centimetre wave region they are virtually only observed when a flare or subflare is in progress.

1959, Siegfried Flügge, Astrophysics the Solar System Volume Encyclopedia of Physics: Volume LII (52), Springer Verlag, page 311:

Solar circumstances have been evaluated for January 28, 1967, the date of an observed ground level enhancement of cosmic rays which was not preceded by observation of a suitably great Ha flare. On the visible solar hemisphere, a bright subflare at S23°E19° occurred in appropriate time association with the cosmic-ray event, and was accompanied by weak x-ray enhancement and radiofrequency emission. If this flare, alone, or in combination with other minor flares observed on the visible hemisphere on January 28 was the source of the energetic cosmic rays recorded on that date, then current thinking regarding the characteristics of cosmic-ray flares must be modified. An initial study of probable circumstances on the invisible hemisphere did not lead to the immediate recognition of a major center of activity as the probable source of a cosmic-ray flare.

1970, Nuclear Science Abstracts 1970-01-31: Volume 24, Issue 2, Superintendent of Government Documents, page 323:

(astronomy, rare) A small flare (explosion or light).


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.


bistellar

The so-called nebula in virgo—a bistellar planetary system in the retrogressive course of envelopment

1914, Mabel P. Malter, The World Process:

It must be stabilized about all three principal axes with a fully automatic, offset, bistellar guidance system .

He tried to adjust the viewscreens so he could see the invisible things around the bistellar system, which Mr. Chamm's viewscreens had been able to show him when they had first arrived here.

2019, David Wayne Hillery, The Second Degree, page 156:

As Kohler (Ibid.) notes, even if we managed to exceed the speed of light by 50% via an Alcubierre drive (or something else), this would still be insufficient for a bistellar government.

2023, J Gottlieb, “Should we colonize (interstellar) space?”, in Interstellar Travel:


starline

(astronomy) A hypothetical or theoretical line connecting a series of stars within a cluster or constellation.


Daphnidian

en-adj

Daphnidian (comparative more Daphnidian, superlative most Daphnidian)

more Daphnidian (comparative)
most Daphnidian (superlative)

(astronomy) Of or relating to the Saturnian moon named for Daphnis.


Aegaeonian

Aegaeonian (comparative more Aegaeonian, superlative most Aegaeonian)

more Aegaeonian (comparative)
most Aegaeonian (superlative)

(astronomy) Of or relating to the Saturnian moon named for Aegaeon.


Methonean

Methonean (comparative more Methonean, superlative most Methonean)

more Methonean (comparative)
most Methonean (superlative)

/mɛθəˈniːən/

(astronomy) Of or relating to the Saturnian moon named for Methone.


Anthean

Anthean (comparative more Anthean, superlative most Anthean)

more Anthean (comparative)
most Anthean (superlative)

(astronomy) Of or relating to the Saturnian moon named for Anthe.


Pallenean

Pallenean (comparative more Pallenean, superlative most Pallenean)

more Pallenean (comparative)
most Pallenean (superlative)

(astronomy) Of or relating to the Saturnian moon named for Pallene.


Telestoan

Telestoan (comparative more Telestoan, superlative most Telestoan)

more Telestoan (comparative)
most Telestoan (superlative)

(astronomy) Of or relating to the Saturnian moon named for Telesto.


Calypsoan

Calypsoan (comparative more Calypsoan, superlative most Calypsoan)

more Calypsoan (comparative)
most Calypsoan (superlative)

(astronomy) Of or relating to the Saturnian moon named for Calypso.


Helenean

Helenean (comparative more Helenean, superlative most Helenean)

more Helenean (comparative)
most Helenean (superlative)

(astronomy) Of or relating to Helene, the Saturnian moon named for Helen.


Polydeucean

Polydeucean (comparative more Polydeucean, superlative most Polydeucean)

more Polydeucean (comparative)
most Polydeucean (superlative)

(astronomy) Of or relating to the Saturnian moon named for Polydeuces.


Deimian

(astronomy) Of or relating to the Martian moon named for Deimos.


Selenian

Alternative form: selenian


Thebean

(astronomy) Of or relating to the Jovian moon named for Thebe.


Himalian

(astronomy) Of or relating to the irregular Jovian moon named for Himalia.


Elarian

(astronomy) Of or relating to the irregular Jovian moon named for Elara.


Pasiphaëan

(astronomy) Of or relating to the irregular Jovian moon named for Pasiphaë.


Sinopean

(astronomy) Of or relating to the irregular Jovian moon named for the mythological Sinope.


Lysithean

(astronomy) Of or relating to the irregular Jovian moon named for Lysithea.


Anankean

/ænəŋˈkiːən/

(astronomy) Of or relating to the irregular Jovian moon named for Ananke.


Ledean

(astronomy) Of or relating to the irregular Jovian moon named for Leda.


horizon problem

(cosmology) The cosmological fine-tuning problem of explaining the observed homogeneity of causally disconnected regions of space in the absence of a mechanism that sets the same initial conditions everywhere.


SGL

en-noun

SGL (countable and uncountable, plural SGLs)

solar gravitational lens
w:solar gravitational lens

(astronomy) Initialism of solar gravitational lens.

(astronomy) Initialism of solar gravity lens.


SGLF

(astronomy) Initialism of solar gravitational lens focus or initialism of solar gravity lens focus.


Nereidian

(astronomy) Of or relating to the irregular Neptunian moon named for the Nereids.


Naiadian

(astronomy) Of or relating to the irregular Neptunian moon named for the Naiads.


Thalassian

(astronomy) Of or relating to the irregular Neptunian moon named for Thalassa.


Despinian

(astronomy) Of or relating to the irregular Neptunian moon named for Despina.


Galatean

/ɡæləˈtiːən/

(astronomy) Of or relating to the irregular Neptunian moon named for Galatea.

(astronomy) Of or relating to the asteroid (74) Galatea.


Larissian

(astronomy) Of or relating to the irregular Neptunian moon named for Larissa.


Halimedean

(astronomy) Of or relating to the irregular Neptunian moon named for Halimede.


Psamathean

/sæməˈθiːən/

(astronomy) Of or relating to the irregular Neptunian moon named for Psamathe.


Saonian

(astronomy) Of or relating to the irregular Neptunian moon named for Sao.


Laomedeian

(astronomy) Of or relating to the irregular Neptunian moon named for Laomedeia.


Nesoan

(astronomy) Of or relating to the irregular Neptunian moon named for Neso.


Hydrian

(astronomy) Of or relating to the Plutonian moon named for Hydra.


Dysnomian

(astronomy) Of or relating to the Eridian moon named for Dysnomia.


Mabian

(astronomy) Of or relating to the Neptunian moon named for Mab.


Perditean

(astronomy) Of or relating to the Neptunian moon named for Perdita.


Rosalindian

(astronomy) Of or relating to the Neptunian moon named for Rosalind.


Julietian

(astronomy) Of or relating to the Neptunian moon named for Juliet.


Desdemonan

(astronomy) Of or relating to the Neptunian moon named for Desdemona.


Cressidian

(astronomy) Of or relating to the Neptunian moon named for Cressida.


Biancan

(astronomy) Of or relating to the Neptunian moon named for Bianca.


Setebosian

(astronomy) Of or relating to the Neptunian moon named for Setebos.


Sycoraxian

(astronomy) Of or relating to the Neptunian moon named for Sycorax.


Calibanian

(astronomy) Of or relating to the Neptunian moon named for Caliban.


Stephanonian

(astronomy) Of or relating to the Neptunian moon named for Stephano.


Margaretian

/ˌmɑːrɡəˈrɛtiən/

(astronomy) Of or relating to the Neptunian moon named for Margaret.


Prosperonian

(astronomy) Of or relating to the Neptunian moon named for Prospero.


Ferdinandian

(astronomy) Of or relating to the Neptunian moon named for Ferdinand.


Orthosian

/ɔːrˈθoʊʒiən/

(astronomy) Of or relating to the irregular Jovian moon Orthosie named for Orthosia.


Thyonean

/ˌθaɪəˈniːən/

(astronomy) Of or relating to the irregular Jovian moon named for Thyone.


Iocastean

(astronomy) Of or relating to the irregular Jovian moon named for Iocaste.


Pasithean

(astronomy) Of or relating to the irregular Jovian moon Pasithee, named for Pasithea.


Kallichorean

(astronomy) Of or relating to the irregular Jovian moon named for Kallichore.


Taygetean

/ˌteɪədʒəˈtiːən/

(astronomy) Of or relating to the Pleiad named for Taygete.

(astronomy) Of or relating to the irregular Jovian moon named for Taygete.


Aoedean

/ˌeɪəˈdiːən/

(astronomy) Of or relating to the irregular Jovian moon named for Aoede.


Hygiean

(astronomy) Of or relating to the asteroid (10) Hygiea.


Euphrosynean

(astronomy) Of or relating to the asteroid (31) Euphrosyne.


Hektorean

(astronomy) Of or relating to the asteroid (624) Hektor.


Nemesian

(astronomy) Of or relating to the asteroid (128) Nemesis.


Diotimean

(astronomy) Of or relating to the asteroid (423) Diotima.


celestial longitude

celestial longitude (plural celestial longitudes)

(astronomy) The longitude in the ecliptic system of coordinates that is measured eastward along the celestial equator.


Hebean

(astronomy) Of or relating to the asteroid (6) Hebe.


Elektrian

(astronomy) Of or relating to the asteroid (130) Elektra.


Electrian

(astronomy) Of or relating to the Pleiad named for Electra.


Hermionean

(astronomy) Of or relating to the asteroid (121) Hermione.


Sea of Moscow

A calque of translingual Mare Muscoviensis (literally “Muscovian Sea”), from New Latin Mare Muscoviensis, from Latin mare (“sea”) + Latin Muscoviensis (“Muscovian, of Muscovy”)

affix

(planetology) A basin in the Moon, orbiting the Earth, in the Solar System.


Local Lynx of Cold Clouds

Blend of Lynx + Local Ribbon of Cold Clouds. From local + Lynx + cold cloud. From being nearby, local, located in the constellation Lynx, composed of interstellar clouds of cold hydrogen.

blend

Local Ribbon of Cold Clouds
Local Ribbon of Cold Clouds#English

(astronomy) A collection of cold interstellar clouds, located at the near end of the Local Ribbon of Cold Clouds, which itself is located in the Local Bubble, in the Local Arm of of the Milky Way galaxy.


Local Ribbon of Cold Clouds

From local + ribbon + cold cloud. From being nearby, local, located in the nearby galaxy, composed of a string of interstellar clouds of cold hydrogen.

(astronomy) A collection of cold interstellar clouds, located in nearby space, in the Local Bubble, in the Local Arm of of the Milky Way galaxy.


BoA

basin of attraction
basin of attraction#English

(acronym, initialism, cosmology) Abbreviation of basin of attraction; the gravitational center of a supercluster of galaxies; a Great Attractor.


giant elliptical galaxy

en-noun

giant elliptical galaxy (plural giant elliptical galaxies)

Coordinate term: dwarf elliptical galaxy

(astronomy) A massive elliptical galaxy that is much larger than other galaxies in its cluster and is often located at the center of that cluster.


dwarf elliptical galaxy

dwarf elliptical galaxy (plural dwarf elliptical galaxies)

Coordinate term: giant elliptical galaxy

(astronomy) An elliptical galaxy that is smaller than an ordinary elliptical galaxy, common in galaxy groups and clusters.


light profile

light profile (countable and uncountable, plural light profiles)

The Sersic model generally provides an accurate description of the global radial light profile of galaxies but it fails to reproduce the inner regions […]

2012, Alessandro Boselli, A Panchromatic View of Galaxies, page 162:

The most extensive analysis of the light profile of a star was carried out by King [K1], who used photographic techniques to determine the surface brightness at radii of more than 10,000 times the half-width at half peak intensity (HW) of the image – a dynamic range of almost 28 magnitudes (Figure 1.13).

2013, Neill I. Reid, Suzanne L. Hawley, New Light on Dark Stars:

(astronomy) A description of the distribution of surface brightness.


last scattering surface

last scattering surface (plural last scattering surfaces)

(astronomy) The horizon in the distant past of the universe at which photons ceased scattering from matter and were able to travel unimpeded to be observed in the present day.


Tsuchinshan-ATLAS

(astronomy) C/2023 A3 (Tsuchinshan–ATLAS), a comet visible to the naked eye in 2024.


Uúba

(astronomy) LTT 9779, a G-type main-sequence star located 264 light-years (81 parsecs) away from the Solar System in the constellation of Sculptor.


sub-Earth

Coordinate term: super-Earth

(astronomy) A planet that is substantially less massive than Earth and Venus.


Earth-sized

(astronomy) Of a planet, that is similar in size to Earth, typically between one-half of or twice its radius.


dawnside

(astronomy) The side of a planet or other body that is experiencing sunrise, a transition from night to day.


duskside

(astronomy) The side of a planet or other body that is experiencing sunset, a transition from day to night.


Rudolphine Tables

(astronomy) The first set of astronomical tables that allowed one to calculate the position of the planets even in the far future.


primordial fluctuations

primordial fluctuations pl (plural only)

(cosmology) The density variations in the early universe which are considered the seeds of all the structure in the universe.


Stelliferous Age

(cosmology) The current period in the history of the universe, in which matter is organized into stars, planets, and galaxies.


Stateira

Stateira

name shared by three women of the Achaemenid dynasty

(astronomy) 831 Stateira a main belt asteroid, named after the wife of Artaxerxes II.


N galaxy

(astronomy, dated) A kind of active galaxy having the visual appearance of a galaxy with a particularly bright, star-like nucleus.


Earth radius

(astronomy) The distance from the center of Earth to a point on or near its surface.


Greisen-Zatsepin-Kuzmin horizon

(astronomy, physics) A theoretical limit on the energy of cosmic rays that reach Earth.


Greisen-Zatsepin-Kuzmin mechanism

(astronomy, physics) A theoretical upper limit on the energies of ultra-high-energy cosmic rays based on interactions with the cosmic microwave background.