Term Index (B)

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Term Index (B)

B: photometric filter for blue light
- B-type star (B): star with spectral characteristics of around 10000-30000 K
- Barnard Catalog (Barnard,B): 1919 catalog of dark nebulae
- epoch B1950.0: midnight 1/1/1950 GMT as used as a time reference
- magnetic flux density (B): vector field describing magnetism in relation to the Lorentz force
- rare designator prefixes: designator prefixes generally used for only a few objects
B field:
- magnetic flux density (B): vector field describing magnetism in relation to the Lorentz force
B-band:
- Hubble Ultra-Deep Field (HUDF): extremely detailed HST image of a small region of space
B-BOP:
- SPICA: plan for a future space IR telescope
B-class:
- B-type star (B): star with spectral characteristics of around 10000-30000 K
B-class star:
- B-type star (B): star with spectral characteristics of around 10000-30000 K
B-E statistics:
- Bose-Einstein statistics: possible distribution of particles not bound by Pauli exclusion
B-mode:
- CMB polarization: effects of scattering and lensing on the CMB
- POLARBEAR: instrument to map CMB polarization
- polarization modes: electric and magnetic aspects of the polarization of electromagnetic radiation
- primordial gravitational waves: gravitational waves formed in the early universe
B-type star (B): star with spectral characteristics of around 10000-30000 K
B-type Subdwarf:
- subdwarf (sd,VI): star less bright than the main sequence given its spectral class
B-V:
- color index: a number that characterizes the color of an object
B/SN:
- Asiago Supernova Catalog (B/SN): 1999 catalog of known supernovae and their galaxies
B1875.0:
- epoch B1950.0: midnight 1/1/1950 GMT as used as a time reference
B1900.0:
- epoch B1950.0: midnight 1/1/1950 GMT as used as a time reference
- terrestrial time (TT): current measure of time for astronomical observations on Earth
B1900.0 epoch:
- epoch: when an object was at a particular set of celestial coordinates
B1925.0:
- epoch B1950.0: midnight 1/1/1950 GMT as used as a time reference
B1950.0:
- epoch B1950.0: midnight 1/1/1950 GMT as used as a time reference
- terrestrial time (TT): current measure of time for astronomical observations on Earth
B1950.0 epoch:
- epoch: when an object was at a particular set of celestial coordinates
B1950.0 equinox:
- J2000.0 equinox: equinox as of the J2000.0 epoch used as a positional reference
B1957+20:
- Black Widow Pulsar (B1957+20, PSR J1959+2048, PSR B1957+20): binary system consisting of a pulsar and small companion
B2:
- Bologna Survey of Radio Sources: 1970s-1980s radio survey
B2K:
- BOOMERanG: 1990s-2000s balloon-borne 1.3-meter millimeter telescope
B3:
- Bologna Survey of Radio Sources: 1970s-1980s radio survey
B[e] star:
- Be star: early star with Balmer emission lines
Baade:
- FourStar Galaxy Evolution Survey (ZFOURGE,Z-FOURGE): infrared deep-survey to detect galaxies
Baade Telescope:
- Magellan Telescopes: pair of 6.5 m optical telescopes in Chile
- PRIMUS: spectrographic survey of galaxies out to redshift 1
Baade's Window: region of sky allowing observation into the galactic center
back end:
- back end instrument: instruments of a telescope that process or combine signals
- front end instrument: instruments of a telescope that detect and encode the signal
back end instrument: instruments of a telescope that process or combine signals
back-of-the-envelope calculation:
- Kelvin-Helmholtz timescale (KH timescale,KH time,τ_KH): time that would radiate away a body's heat energy given its luminosity
background:
- cosmic background radiation (CBR): electromagnetic radiation coming from every direction
- cosmic gamma ray background (CGB): gamma-ray radiation seen everywhere
- cosmic infrared background (CIB,CIBR): widespread infrared radiation not associated with known sources
- cosmic microwave background (CMB,CMBR,CBR,MBR): microwave radiation coming from every direction
- cosmic optical background (COB): widespread optical radiation not associated with known sources
- cosmic X-ray background (CXB,CXRB,CXBR): X-ray radiation coming from outside the Milky Way
- diffuse emission: electromagnetic radiation not confined to a point source
- extragalactic background light (EBL): electromagnetic radiation from star formation and AGNs
Background Imaging of Cosmic Extragalactic Polarization:
- BICEP2: survey to measure the polarization of the CMB
backward Fourier transform:
- Fourier transform: systematic method of breaking down functions into periodic components
backward model:
- forward model: model producing potential observable values from parameters
Badgerys Creek 101MHz Interferometer:
- Badgerys Creek Interferometer 101MHz Survey (Mills): early 1950s survey of southern-hemisphere radio sources
Badgerys Creek Interferometer 101MHz Survey (Mills): early 1950s survey of southern-hemisphere radio sources
baffle:
- Lyot stop: optical element to block unwanted light within instruments
- stray light: unintended light reaching a telescope's sensors
Bailey classification:
- RR Lyrae variable (RRL,RR): star with periodic variation often in globular clusters
BAL:
- rare designator prefixes: designator prefixes generally used for only a few objects
Balbus-Hawley Instability:
- magnetorotational instability (MRI): instability in the fluid of a disk from MHD effects
Balloon Observations of Millimetric Extragalactic Radiation and Geophysics:
- BOOMERanG: 1990s-2000s balloon-borne 1.3-meter millimeter telescope
Balloon-borne Large Aperture Submillimeter Telescope:
- BLAST: balloon-borne 1.8 m submillimeter telescope
Balmer:
- Balmer series (H): hydrogen lines for electrons settling from n > 2 to n = 2
Balmer discontinuity:
- Balmer jump: abrupt change in stellar spectrum at end of Balmer series
Balmer jump: abrupt change in stellar spectrum at end of Balmer series
Balmer limit:
- Balmer jump: abrupt change in stellar spectrum at end of Balmer series
- Balmer series (H): hydrogen lines for electrons settling from n > 2 to n = 2
- Balmer-break galaxy (BBG): a galaxy emitting very little shorter than 3646 angstroms
Balmer series (H): hydrogen lines for electrons settling from n > 2 to n = 2
- Balmer jump: abrupt change in stellar spectrum at end of Balmer series
- Balmer-break galaxy (BBG): a galaxy emitting very little shorter than 3646 angstroms
- Be star: early star with Balmer emission lines
- H-alpha (Ha,Hα, H-α): hydrogen line for electrons settling from n = 3 to n = 2
Balmer's constant:
- Balmer series (H): hydrogen lines for electrons settling from n > 2 to n = 2
Balmer-break galaxy (BBG): a galaxy emitting very little shorter than 3646 angstroms
band:
- B: photometric filter for blue light
- extreme ultraviolet (EUV,XUV): electromagnetic radiation in the range of 10-124 nm
- extremely low frequency (ELF): electromagnetic radiation, frequency 3 Hz to 30 Hz
- far infrared (FIR,far-IR): infrared radiation with wavelengths in the 30-450 μm range
- G band: band of visible light around 5100 angstroms
- gamma rays (GR): electromagnetic radiation, wavelength 10 picometers and less
- high frequency (HF): electromagnetic radiation, frequency 3-30 MHz
- I band: photometric filter for near infrared light
- infrared (IR): electromagnetic radiation, wavelength 0.74-300 micrometers
- K band: atmospheric window centered around 2.2 microns, or 136 THz
- microwave: electromagnetic radiation, frequency 300 MHz to 300 GHz
- mid infrared (MIR,mid-IR): infrared radiation with wavelengths in the 7.5-25 μm range
- near infrared (NIR,near-IR): electromagnetic radiation in the range of 800-2500 nm
- OIR: a spectral "band name" for both visible light and infrared
- passband: range of electromagnetic wavelengths that a filter allows
- R band: band of visible light around 6500 angstroms
- radio: electromagnetic radiation, frequency 3kHz to 300GHz
- spectral band: set of related, closely-packed spectral lines
- subradio: electromagnetic radiation, frequency below 3 kHz
- super low frequency (SLF): electromagnetic radiation, frequency 30 Hz to 300 Hz
- tremendously low frequency (TLF): electromagnetic radiation, frequency below 3 Hz
- U: photometric filter for ultraviolet light
- ultra low frequency (ULF): electromagnetic radiation, frequency 300 Hz to 3 kHz
- ultra-high-energy gamma rays (UHEGR): energetic gamma rays with more than 100 TeV photon energy
- ultraviolet (UV): electromagnetic radiation, wavelength 10-400 nm
- UVOIR: a spectral "band name" covering UV, visible light, and IR
- V: photometric filter for visible light
- very low frequency (VLF): electromagnetic radiation, frequency 3-30 kHz
- very-high-energy gamma rays (VHEGR): energetic gamma rays with 100 GeV to 100 TeV photon energy
- visible light: electromagnetic radiation, wavelength 390-750 nm
- X-ray: electromagnetic radiation, wavelength 0.01 to 10 nanometers
- XEUV: electromagnetic radiation in the range of 0.15-400 nm
- zone: apparent "horizontal" band in an atmosphere
band absorption:
- continuous absorption: the absorption of a whole section of a spectrum
band shifting: effect of redshift on photometry
bandpass filter:
- filter: optical device to filter out part of the EMR spectrum
bandwidth: number of hertz between minimum and maximum frequencies
BAO:
- baryon acoustic oscillations (BAO): density fluctuations stemming from acoustic waves in the early universe
- Baryon Oscillation Spectroscopic Survey (BOSS): survey of spatial distribution of luminous red galaxies and quasars
- BigBOSS: BOSS survey follow-on
BAO standard ruler:
- baryon acoustic oscillations (BAO): density fluctuations stemming from acoustic waves in the early universe
BAR:
- atm: unit of pressure
- bar: central feature of some spiral galaxies
- galactic bulge: bulge of many stars in the center of the Milky Way
- rare designator prefixes: designator prefixes generally used for only a few objects
barium:
- Am star: A-type star with metallic lines
barium star:
- binary star: system of two stars co-orbiting
Barnard:
- Barnard Catalog (Barnard,B): 1919 catalog of dark nebulae
Barnard Catalog (Barnard,B): 1919 catalog of dark nebulae
Barnard Catalogue of 349 Dark Objects in the Sky:
- Barnard Catalog (Barnard,B): 1919 catalog of dark nebulae
Barnard object:
- Barnard Catalog (Barnard,B): 1919 catalog of dark nebulae
Barnard's Star: nearby red dwarf
baroclinic atmosphere:
- baroclinicity: measure of misalignment of fluid density and pressure
baroclinic instability:
- baroclinicity: measure of misalignment of fluid density and pressure
baroclinicity: measure of misalignment of fluid density and pressure
barometric admittance:
- admittance: effect of atmospheric pressure on gravity
barotropic atmosphere:
- baroclinicity: measure of misalignment of fluid density and pressure
barred:
- bar: central feature of some spiral galaxies
- spiral galaxy: flat galaxy with spiraling arms
barred galaxy:
- galaxy classification: morphological classification of galaxies
- spiral galaxy: flat galaxy with spiraling arms
barred spiral galaxy:
- bar: central feature of some spiral galaxies
barrel aberration:
- aberration: types of flaws in telescope images
barrel distortion: distortion such that a square shows with convex edges
barrier: challenging issue regarding planet formation
- bouncing barrier: the problem that the seeds of planets would rebound rather than merge
- electrostatic barrier: the problem that dust grains will repel and not join to form planet seeds
- fragmentation barrier: the problem that the seeds of planets would break apart rather than merge
- kilometer size barrier: a barrier to accretion on the order of a kilometer diameter
- meter size barrier: a barrier to planet formation on the order of a meter diameter
- radial-drift barrier: the problem that forming planets would drift inward into the star
barrier penetration:
- quantum tunneling: quantum mechanical effect of particles passing through a barrier
barriers:
- planet formation: process by which planets form
barycenter: center of mass of two orbiting bodies
barycentric coordinate time:
- time standard: method of designating points in time and quantifying time periods
barycentric coordinates:
- barycenter: center of mass of two orbiting bodies
barycentric dynamical time:
- time standard: method of designating points in time and quantifying time periods
barycentric Julian day BJD:
- Julian date (JD): time in days since noon UT November 24 4714 BC Gregorian
baryogenesis:
- antimatter: similar to normal matter but with opposite electrical charge
baryon: protons, neutrons, and other three-quark particles
- particle: very small thing
baryon acoustic oscillations (BAO): density fluctuations stemming from acoustic waves in the early universe
baryon density:
- Lambda-CDM model (ΛCDM,LCDM): Big-Bang cosmological model with a cosmological constant and cold dark matter
Baryon Oscillation Spectroscopic Survey (BOSS): survey of spatial distribution of luminous red galaxies and quasars
- Sloan Digital Sky Survey (SDSS): imaging survey of 500,000,000 objects in 35% of sky
baryonic gas fraction:
- gas fraction: fraction of a galaxy or cluster consisting of gas
baryonic mass density:
- astronomical quantities: some astronomy amounts/numbers
- critical density (ρ_c): density of the universe which leaves it flat
- mass density: density of a volume of space
baryonic matter: ordinary matter made up of protons and neutrons
- baryon: protons, neutrons, and other three-quark particles
- dark matter: matter suggested by gravity in galaxies and galaxy clusters
baryonic Tully-Fisher relation:
- Tully-Fisher relation (TFR): relation between spiral galaxy luminosity and line width
Bas:
- Basel Open Cluster Catalogue (Basel): list of open clusters
basalt: an igneous rock type that shows rapid cooling
Basel:
- Basel Open Cluster Catalogue (Basel): list of open clusters
Basel Astronomical Institute:
- Basel Open Cluster Catalogue (Basel): list of open clusters
Basel Open Cluster Catalogue (Basel): list of open clusters
baseline: distance between dishes of an interferometer
- parallax: angle due to different lines of sight
basicity:
- acidity (pH): measure of the activity of hydrogen ions in a solution
basis function: one of a set of functions used to approximate a function of interest
BAT:
- Swift: satellite for studying gamma-ray bursts
BAT99:
- rare designator prefixes: designator prefixes generally used for only a few objects
BATC: photometric survey of Milky Way stars
bathymetry: study and measurement of sea depths
BATSE:
- Compton Gamma Ray Observatory (CGRO,GRO): 1990s space observatory for gamma ray observation
Bayer designation: star designation system dating from 1600s
Bayes factor:
- Bayesian statistics: statistics method assigning probability to your belief
Bayes' law:
- Bayesian statistics: statistics method assigning probability to your belief
Bayes' rule:
- Bayesian statistics: statistics method assigning probability to your belief
Bayes' theorem:
- Bayesian statistics: statistics method assigning probability to your belief
Bayesian inference:
- Bayesian statistics: statistics method assigning probability to your belief
Bayesian probabilities:
- Bayesian statistics: statistics method assigning probability to your belief
Bayesian statistics: statistics method assigning probability to your belief
- Markov chain Monte Carlo (MCMC): model technique to approximate multi-dimensional integrals
BAZ:
- rare designator prefixes: designator prefixes generally used for only a few objects
BB:
- black body (BB): idealized object that reflects no light
- CMB polarization: effects of scattering and lensing on the CMB
BBFS:
- HEAO-2: 1978 X-ray observatory space mission
BBG:
- Balmer-break galaxy (BBG): a galaxy emitting very little shorter than 3646 angstroms
BBH:
- black hole binary (BHB,BBH): two black holes co-orbiting
BBN:
- Big Bang nucleosynthesis (BBN): creation of atomic nuclei in the very early universe
BCD:
- dwarf galaxy: small galaxy with a few billion stars
- dwarf galaxy classification: terms for of dwarf galaxy types
BCE:
- variable star: star that varies in magnitude
BCEP:
- variable star: star that varies in magnitude
BCG:
- brightest cluster galaxy (BCG): a cluster's most luminous galaxy
- dwarf galaxy: small galaxy with a few billion stars
Bcool: project studying stellar magnetism
BCS:
- Ariel 5: 1970s X-ray space telescope
- Yohkoh: 1990s Japanese solar observatory spacecraft
BCVS:
- Bibliographic Catalog of Variable Stars (BCVS): listing of references to variable stars
BD:
- Bonner Durchmusterung Catalog (BD): well-known astrometric catalog from late 1800s
- brown dwarf (BD): star-like object with less mass than a star
- dropout: means of identifying distant galaxies
BD+36 2147:
- Lalande 21185: nearby red dwarf
BDF: field used in search for distant galaxies
BDS:
- Burnham Double Star Catalogue (BDS,BU): 1906 catalog with multiple star systems and non-orbiting double stars
BDS03:
- rare designator prefixes: designator prefixes generally used for only a few objects
Be:
- Berkeley Open Cluster Catalogue (Be): list of open clusters
Be star: early star with Balmer emission lines
- shell star (sh): type of star with broad and narrow absorption lines
Beagle 2:
- Mars Express: Mars probe launched by ESA in 2003
beam: portion of a sky that a radio telescope is viewing
beam pattern:
- beam: portion of a sky that a radio telescope is viewing
beam width:
- beam: portion of a sky that a radio telescope is viewing
beamforming:
- beam: portion of a sky that a radio telescope is viewing
beaming:
- isotropy: uniformity in all directions
BearCLAW:
- AstroBEAR: MHD simulation system
BEC:
- Bose-Einstein condensate (BEC): rare state of matter possible at cryogenic temperatures
Becker, White, and Edwards Catalog (BWE): 1990s radio catalog from a Green Bank 300ft Telescope survey
BEFS:
- Berkeley Extreme and Far-UV Spectrometer (BEFS): 1990s UV spectrometer used on two shuttle missions
Beijing-Arizona-Taiwan-Connecticut Survey:
- BATC: photometric survey of Milky Way stars
BEL:
- broad emission line region: region within an AGN with broad emission lines
BEL cloud:
- broad emission line region: region within an AGN with broad emission lines
BEL region:
- broad emission line region: region within an AGN with broad emission lines
Belgian:
- TRAPPIST: ground-based automatic transiting planet finding telescope
bell curve:
- full width at half maximum (FWHM): a measure of the width of a hump-shaped curve
- Gaussian function: function producing the bell curve
- window function: function with a zero value outside some specific range
Bellatrix:
- Orion: well-known constellation in the northern hemisphere
belt:
- superrotating wind: wind traveling in the same direction as the planet is rotating
- zone: apparent "horizontal" band in an atmosphere
Bennett:
- rare designator prefixes: designator prefixes generally used for only a few objects
Bennu:
- 101955 Bennu: near-Earth asteroid that is the target of a sample-return mission
benzene:
- hydrocarbon (HC): any compound of just carbon and hydrogen
BepiColombo: mission to Mercury
- Mercury: inner-most and smallest planet in the solar system
BeppoSAX: Italian-Dutch space X-ray telescope
Berkeley:
- Berkeley Open Cluster Catalogue (Be): list of open clusters
- PAPER: radio interferometer for 21-cm measurement
Berkeley Extreme and Far-UV Spectrometer (BEFS): 1990s UV spectrometer used on two shuttle missions
Berkeley Open Cluster Catalogue (Be): list of open clusters
Berkeley-Illinois-Maryland Association:
- BIMA telescope: millimeter interferometer in operation 1985 to 2005
Bernard Lyot Telescope:
- Zeeman-Doppler imaging (ZDI): technique for imaging stellar magnetic fields
Bernes:
- rare designator prefixes: designator prefixes generally used for only a few objects
Bernstein polynomial: polynomial form capable of producing arbitrary shapes
beryllium:
- triple alpha process: fusion reaction chain turning helium-4 into carbon
Besselian date:
- epoch: when an object was at a particular set of celestial coordinates
Besselian epoch:
- epoch B1950.0: midnight 1/1/1950 GMT as used as a time reference
Besselian year:
- epoch B1950.0: midnight 1/1/1950 GMT as used as a time reference
beta (β): ratio of plasma pressure to magnetic pressure
Beta Canis Majoris star:
- variable star: star that varies in magnitude
Beta Centauri: second brightest star in Centaurus
Beta Cephei variable:
- variable star: star that varies in magnitude
beta decay: radioactivity such that an electron or positron is emitted
beta drift: tendency for a cyclone to drift poleward and westward
Beta Lyrae variable:
- variable star: star that varies in magnitude
Beta Orionis:
- Rigel: brightest star in constellation Orion
beta particle:
- alpha particle: essentially a helium nucleus produced by radioactivity
- beta decay: radioactivity such that an electron or positron is emitted
- particle spectrometer: device to determine the characteristics of incoming particles
Beta Per:
- Algol (Beta Per,β Per): multiple star system demonstrating effects of mass transfer
Beta Persei:
- Algol (Beta Per,β Per): multiple star system demonstrating effects of mass transfer
Beta Pictoris:
- Beta Pictoris b (β Pic b): super Jupiter discovered in 2008
Beta Pictoris b (β Pic b): super Jupiter discovered in 2008
beta plane:
- Coriolis force: apparent force in a rotating frame of reference
beta ray:
- radioactive heating: a source of heat of some planets and moons
beta-decay stable isobars:
- valley of beta stability: set of isotopes not prone to beta decay
Betelgeuse: second brightest star in constellation Orion
- Orion: well-known constellation in the northern hemisphere
bethe:
- foe: unit of energy on the order of a supernova's output
BF:
- Voigt profile: mathematical shape that models spectral lines
BFS:
- rare designator prefixes: designator prefixes generally used for only a few objects
BG4:
- BlackGEM: telescope array in development to follow up gravitational wave signals
BH:
- black hole (BH): region of such high mass that light cannot escape
- direct collapse black hole (DCBH): theoretical means for quick formation of SMBHs
- primordial black hole: black holes forming at the most dense volumes when inflation ceased
BH merger:
- black hole merger: two black holes meeting and forming one
BH model:
- black hole model: description of a BH using math or computation
BHAD:
- accretion disk: disk around an astronomical body of material that is accreting
BHAR:
- black hole accretion rate (BHAR): measure, especially used for AGNs
BHB:
- black hole binary (BHB,BBH): two black holes co-orbiting
- blue horizontal branch (BHB): blue end of the horizontal branch
BHM:
- Sloan Digital Sky Survey (SDSS): imaging survey of 500,000,000 objects in 35% of sky
BHXRT:
- transient: observed change in the sky
BHXT:
- transient: observed change in the sky
BI:
- rare designator prefixes: designator prefixes generally used for only a few objects
bias:
- Eddington bias: selection bias from mistaking something common for something rare
- galaxy bias: degree to which galaxy density fails to correspond to dark matter density
- low-surface-brightness galaxy (LSB galaxy): galaxies less bright than those historically identified
- Malmquist bias: selection bias from detecting only the brighter objects
- Scott effect: bias toward finding clusters that have bright galaxies
- volume weighting: method of accommodating the Malmquist bias
bibcode: reference code for a journal article
Bibliographic Catalog of Variable Stars (BCVS): listing of references to variable stars
Bica:
- rare designator prefixes: designator prefixes generally used for only a few objects
bicarbonate:
- acidity (pH): measure of the activity of hydrogen ions in a solution
- carbonate system: system governing water and CO2 in the presence of each other
BICEP:
- BICEP2: survey to measure the polarization of the CMB
BICEP2: survey to measure the polarization of the CMB
BICEP3:
- BICEP2: survey to measure the polarization of the CMB
Biden:
- Kuiper Belt (K Belt,KB): further part of solar system beyond Neptune
Big Bang: theoretical event when the universe expanded from a point
- Big Bang nucleosynthesis (BBN): creation of atomic nuclei in the very early universe
- black hole (BH): region of such high mass that light cannot escape
- cosmic time: time since the Big Bang
- cosmology: study of the life of the universe
- dark age: interval when the universe's hydrogen atoms were neutral
- early universe: from the Big Bang to recombination
- epoch of reionization (EOR): time when the universe's neutral hydrogen atoms ionized
- lithium (Li): metal, Li, atomic number 3
- nucleosynthesis: creation of atomic nuclei
- recombination: time when the universe's ionized hydrogen atoms neutralized
Big Bang nucleosynthesis (BBN): creation of atomic nuclei in the very early universe
- nucleosynthesis: creation of atomic nuclei
Big Bang theory:
- Big Bang: theoretical event when the universe expanded from a point
Big Ear:
- Ohio Radio Survey (OSS): 1960s radio survey by Ohio State University
BigBOSS: BOSS survey follow-on
BigBOSS Spectrograph:
- BigBOSS: BOSS survey follow-on
Bigelow Sky Survey:
- Catalina Sky Survey (CSS): survey of near-Earth objects
BIMA:
- BIMA telescope: millimeter interferometer in operation 1985 to 2005
BIMA radio telescope array:
- BIMA telescope: millimeter interferometer in operation 1985 to 2005
BIMA telescope: millimeter interferometer in operation 1985 to 2005
binary:
- binary star: system of two stars co-orbiting
binary asteroid:
- binary minor planet (BMP): minor planet with another body orbiting it
binary black hole:
- black hole binary (BHB,BBH): two black holes co-orbiting
binary burning:
- globular cluster (GC): spherical group of stars orbiting a galaxy
binary minor planet (BMP): minor planet with another body orbiting it
binary neutron star (BNS,NSB,DNS): two neutron stars co-orbiting
binary population synthesis:
- stellar population synthesis (SPS): using spectral characteristics of galaxies to characterize their stellar populations
binary SMBH (BSMBH,SMBBH,SMBHB): co-orbiting supermassive black holes
binary star: system of two stars co-orbiting
- Achernar: ninth-brightest star in the sky
- Algol (Beta Per,β Per): multiple star system demonstrating effects of mass transfer
- Alpha Centauri: nearest star system
- Beta Centauri: second brightest star in Centaurus
- Black Widow Pulsar (B1957+20, PSR J1959+2048, PSR B1957+20): binary system consisting of a pulsar and small companion
- DQ Tau: young binary star system
- Epsilon Indi (ε Indi,ε Ind): nearby star system including two brown dwarf companions
- G239-25: nearby red dwarf with brown dwarf companion
- GG Tau: much-studied quadruple star system
- GRO J1655-40: microquasar
- HD 133131: binary star system with exoplanets
- Hulse-Taylor Binary (PSR B1913+16,PSR J1915+1606, PSR 1913+16): binary system consisting of a pulsar and neutron star
- J1713-0747: binary system with millisecond pulsar and white dwarf
- Luhman 16: nearby binary brown dwarf
- Luyten 726-8: nearby binary star system
- Procyon: brightest star in Canis Minor
- Rigel: brightest star in constellation Orion
- Scholz's Star: nearby binary star with red dwarf and brown dwarf
- Sirius: brightest star in the sky
- T Tauri: variable star taken as example of young star
binary star type:
- astrometric binary: binary star system detected by observing the movement of a star
- binary neutron star (BNS,NSB,DNS): two neutron stars co-orbiting
- black hole binary (BHB,BBH): two black holes co-orbiting
- common envelope: binary star system surrounded by a single gas cloud
- double-line spectroscopic binary (SB2): spectroscopic binary star where a specific line shows up at two different wavelengths
- eclipsing binary (E): binary star system detected by variations in magnitude
- galactic binary: system of two object co-orbiting within the Milky Way
- post-common envelope binary (PCEB): binary star system showing unusual stellar evolution
- spectroscopic binary (SB): binary star detected by movement indicated by Doppler shifts in the spectrum
- spectrum binary: binary star detectable because its spectrum looks like that of two stars
- visual binary: binary star system in which both stars can be seen
binary stars:
- accretion: enlargement of an astronomical body by gravitationally attracting additional mass
- accretion disk: disk around an astronomical body of material that is accreting
- Aitken Double Star Catalogue (ADS): 1932 catalog with both multiple-star systems and non-orbiting double stars
- binary star: system of two stars co-orbiting
- Burnham Double Star Catalogue (BDS,BU): 1906 catalog with multiple star systems and non-orbiting double stars
- Catalogue of Southern Double Stars: 1955 catalog with multiple star systems and non-orbiting double stars
- contact binary: binary stars orbiting so close they are touching
- double star: two stars close together in the sky
- Dunlop Double Star Catalogue (DUN): 1829 catalog of double stars viewed from Australia
- ejection: forcing or throwing something out
- hardness: measure of the binding energy of a binary
- Heggie-Hills law: hard binary stars generally get harder when encountering a third star
- Kepler-16b: exoplanet orbiting a binary star
- mass function: measure of binaries that constrains the masses
- multiplicity fraction: fraction of star systems that are multiple-star systems
- optical double: double star where the two are not gravitationally bound
- Rossiter-McLaughlin effect (RM effect,RM): effect of transit on visible spectrum of the star
- stellar population synthesis (SPS): using spectral characteristics of galaxies to characterize their stellar populations
- Struve Catalogs: two catalogs of double stars
- symbiotic binary (SS): giant star transferring mass to a somewhat distant companion
- transit timing variations (TTV): variations in the timing of the transits of exoplanets and binaries
- wide binaries (WB): binary stars thousands of AU apart
- X-ray burster (XRB): neutron star binary producing nova-like bursts
binary supermassive black hole:
- binary SMBH (BSMBH,SMBBH,SMBHB): co-orbiting supermassive black holes
binary system:
- binary star: system of two stars co-orbiting
binary TD:
- neutron star merger: two neutron stars meeting and forming one
binary tidal deformability:
- neutron star merger: two neutron stars meeting and forming one
binary TNO:
- binary minor planet (BMP): minor planet with another body orbiting it
binary trans-Neptune object:
- binary minor planet (BMP): minor planet with another body orbiting it
binary X-ray pulsar:
- pulsar (PSR): type of astronomical body with EMR in regular cycles of seconds or less
binary X-ray system:
- binary star: system of two stars co-orbiting
binary YORP:
- Yarkovsky-O'Keefe-Radzievskii-Paddack effect (YORP): rotational effect on asymmetric asteroids
binding energy: energy needed to separate two objects
binomial coefficients:
- Legendre polynomials: useful sequence of polynomials
BINOSPEC:
- MMT: 6.5 meter telescope at Mt. Hopkins, Arizona
biofluorescence: common fluorescence in organisms to dissipate harmful UV radiation
- fluorescence: mechanism by which molecules emit a longer wavelength than they absorb
biology:
- astrobiology: study of extra-terrestrial life
- glycine (Gly,G): smallest of the twenty common amino acids
- mass extinction: event in which many species went extinct
- molecular handedness: mirror-imaged variants of some molecules
- water activity (a_w): measure of partial vapor pressure of water
biomarker:
- biosignature: sign of life
biosignature: sign of life
- astrobiology: study of extra-terrestrial life
bipolar outflow: streams of matter from the poles of a protostar
Birkhoff's theorem: shows GR qualities of a spherically-symmetric mass
bispectrum:
- N-point function: general term for analyses-techniques of spatial data
Biurakan:
- rare designator prefixes: designator prefixes generally used for only a few objects
BL:
- Breakthrough Listen (BL): SETI survey using GBT and Parkes Observatory
- spectral line designation: labels used to identify spectral lines
BL Lac object:
- blazar: very compact variable quasar
- Roma-BZCAT: 2008 catalog of blazars
BL Lacertae:
- blazar: very compact variable quasar
black body (BB): idealized object that reflects no light
- brightness temperature (T_B): temperature of an equivalent black body in terms of intensity
- gray body: ideal object that reflects the same fraction of light at any wavelength
- Planck function: yields black body curve
- Rayleigh-Jeans law: yields approximation of black body curve useful at low frequencies
- Wien approximation: yields approximation of black body curve useful at short wavelengths
- Wien's displacement law: temperature times wavelength with maximum intensity equals a constant
black body radiation:
- spectral index (α): power by which an object's flux depends on frequency
- Thermal Bremsstrahlung: type of EMR produced by thin, hot plasma
black body temperature:
- effective temperature (T_eff,Teff): temperature of an equivalent black body in terms of total radiation
black dwarf:
- brown dwarf (BD): star-like object with less mass than a star
- white dwarf (WD): stellar remnant of mostly electron-degenerate matter
Black Eye Galaxy:
- M64: nearby dusty galaxy
black hold candidate:
- stellar-mass black hole: black hole that is a stellar remnant
black hole (BH): region of such high mass that light cannot escape
- compact object (CO): dense astronomical body such as white dwarf or denser
- direct collapse black hole (DCBH): theoretical means for quick formation of SMBHs
- primordial black hole: black holes forming at the most dense volumes when inflation ceased
black hole accretion disk:
- accretion disk: disk around an astronomical body of material that is accreting
black hole accretion rate (BHAR): measure, especially used for AGNs
- accretion rate: rate of addition of mass to an object
black hole binary (BHB,BBH): two black holes co-orbiting
Black Hole Mapper:
- Sloan Digital Sky Survey (SDSS): imaging survey of 500,000,000 objects in 35% of sky
black hole merger: two black holes meeting and forming one
black hole model: description of a BH using math or computation
black hole X-ray transient:
- transient: observed change in the sky
black holes:
- accretion: enlargement of an astronomical body by gravitationally attracting additional mass
- accretion disk: disk around an astronomical body of material that is accreting
- advection dominated accretion flow (ADAF): accretion without radiating much energy
- binary SMBH (BSMBH,SMBBH,SMBHB): co-orbiting supermassive black holes
- black hole accretion rate (BHAR): measure, especially used for AGNs
- black hole merger: two black holes meeting and forming one
- black hole model: description of a BH using math or computation
- Blandford-Payne mechanism (BP process): means of extracting BH rotational energy by magnetized accretion disk
- Blandford-Znajek mechanism (BZ process): means of extracting BH rotational energy by magnetized accretion disk
- direct collapse black hole (DCBH): theoretical means for quick formation of SMBHs
- ejection: forcing or throwing something out
- ergosphere: type of region of space around rotating black hole
- event horizon (EH): surface-shape around a black hole through which light cannot escape
- extreme mass ratio inspiral (EMRI): inspiraling pair of objects with mass ratio beyond 10,000
- final parsec problem: lack of a convincing theory on how SMBHs can reach each other
- gas streamer: stream of gas
- gravitational singularity: point where density and gravity reach infinity
- GRO J1655-40: microquasar
- innermost stable circular orbit (ISCO): border of region surrounding a BH in which orbits are unstable
- jet: stream of matter from an astronomical body
- law of cosmic censorship: a singularity cannot be observed
- M-sigma relation: relation between galaxy center's velocity dispersion and SMBH mass
- microquasar: stellar-sized black hole with quasar-like activity
- Penrose process: process by which energy can be extracted from black hole's rotation
- photon sphere: surface surrounding black hole where photons can orbit
- primordial black hole: black holes forming at the most dense volumes when inflation ceased
- retrograde accretion: accretion disk spinning in opposite direction to the body
- Salpeter timescale: timescale for black hole growth
- Schwarzschild radius: radius of a black hole's event horizon
- Soltan argument: distant quasars imply SMBHs still exist
- spacetime diagram: graph of simplified spacetime, with fewer space dimensions
- strong-field gravity: gravity much stronger than in the solar system such as near a black hole
- supermassive black hole (SMBH): black hole with a mass of millions to billions of solar masses
- superradiance: Exotic quantum-mechanics light-amplification phenomenon
- tidal disruption event (TDE,TDF): star pulled apart by black hole tidal forces
- ultraluminous X-ray source (ULX): X-ray source with luminosity between a star and an AGN
Black Widow Pulsar (B1957+20, PSR J1959+2048, PSR B1957+20): binary system consisting of a pulsar and small companion
black-body radiation: EMR due to the temperature of a body with a characteristic spectrum
- continuum emission: continuous spectrum such as black body radiation or bremsstrahlung
- emissivity: measure of a material's efficiency at radiating thermal radiation
- thermal emission: EMR due to a body's heat
black-body spectrum:
- black body (BB): idealized object that reflects no light
- black-body radiation: EMR due to the temperature of a body with a characteristic spectrum
- power law: relationship with one quantity a power of another
- Rayleigh-Jeans law: yields approximation of black body curve useful at low frequencies
- spectral index (α): power by which an object's flux depends on frequency
- thermal emission: EMR due to a body's heat
- Wien approximation: yields approximation of black body curve useful at short wavelengths
blackbody:
- black body (BB): idealized object that reflects no light
BlackGEM: telescope array in development to follow up gravitational wave signals
- La Silla Observatory (LSO): Atacama-desert observatory run by ESO
BLAGN:
- active galactic nucleus (AGN): central region of a galaxy with extremely high luminosity
- Seyfert galaxy: visible active galaxy
Blanco 4m:
- Cerro Tololo Inter-American Observatory (CTIO): NOAO observatory in Chile with Blanco telescope
- Dark Energy Survey (DES): survey aimed at mapping the universe's expansion
- Deep Lens Survey (DLS): investigating mass distribution of the universe
- Multiwavelength Survey by Yale-Chile (MUSYC): optical/NIR survey of four deep fields
- National Optical Astronomy Observatory (NOAO): US optical astronomy organization
- NOAO Deep Wide-field Survey (NDWFS): survey investigating large scale structure of the universe
- Supernova Cosmology Project (SCP): used supernova data to determine a history of the universe's expansion
- Víctor M. Blanco Telescope: 4 m reflector telescope in Chile
Blandford-Payne mechanism (BP process): means of extracting BH rotational energy by magnetized accretion disk
Blandford-Payne process:
- Blandford-Payne mechanism (BP process): means of extracting BH rotational energy by magnetized accretion disk
Blandford-Znajek mechanism (BZ process): means of extracting BH rotational energy by magnetized accretion disk
- Penrose process: process by which energy can be extracted from black hole's rotation
Blandford-Znajek process:
- Blandford-Znajek mechanism (BZ process): means of extracting BH rotational energy by magnetized accretion disk
blanketing effect:
- line blanketing: so many bunched spectral lines that they cannot be distinguished
BLAST: balloon-borne 1.8 m submillimeter telescope
BLAST-TNG:
- BLAST: balloon-borne 1.8 m submillimeter telescope
BLASTPol:
- BLAST: balloon-borne 1.8 m submillimeter telescope
blastwave: spherical shock wave from a small volume
blazar: very compact variable quasar
- 3C 273: first quasar discovered
- Roma-BZCAT: 2008 catalog of blazars
blazars:
- Whole Earth Blazer Telescope (WEBT): international initiative to gather blazar lightcurves
blaze angle:
- grating: spectrometer component
blazed grating:
- grating: spectrometer component
blend analysis:
- blended spectra: an observed spectrum comprising light from multiple objects
Blendanal:
- blended spectra: an observed spectrum comprising light from multiple objects
blended spectra: an observed spectrum comprising light from multiple objects
Blender:
- blended spectra: an observed spectrum comprising light from multiple objects
BLG:
- OGLE: survey searching for microlensing transients
blind survey: survey conducted independently of prior information
BLL:
- blazar: very compact variable quasar
BLLAC:
- blazar: very compact variable quasar
blow off:
- atmospheric escape: escape of gas particles from a planet's atmosphere
blowoff:
- hydrodynamic escape: ongoing escape of gas particles from atmosphere
BLR:
- broad-line region (BLR): region in center of active galaxy where spectral lines are broad
- Seyfert galaxy: visible active galaxy
BLR cloud:
- broad-line region (BLR): region in center of active galaxy where spectral lines are broad
blue:
- B: photometric filter for blue light
- globular cluster (GC): spherical group of stars orbiting a galaxy
blue compact dwarf galaxy:
- dwarf galaxy: small galaxy with a few billion stars
- dwarf galaxy classification: terms for of dwarf galaxy types
blue compact galaxy:
- dwarf galaxy: small galaxy with a few billion stars
blue dropout galaxy:
- dropout: means of identifying distant galaxies
blue galaxy:
- galaxy: gravitationally-bound group of stars
- galaxy main sequence: relation between galaxies' star formation and stellar mass
blue giant:
- asymptotic giant branch (AGB): a second stage of helium burning in some stars
- B-type star (B): star with spectral characteristics of around 10000-30000 K
- giant star: star larger than main sequence stars
- red giant: very bright red star
blue horizontal branch (BHB): blue end of the horizontal branch
blue hypergiant:
- hypergiant: extremely bright stars
blue kilonova model:
- kilonova (KN): explosive event larger than a nova and smaller than a supernova
blue noise:
- red noise: noise tending toward lower frequencies
blue shift:
- data cube: "table" of numerical data covering three dimensions
- line broadening: processes causing a spectral line to have width
- redshift (z): change to longer wavelengths due to Doppler effects
blue straggler:
- open cluster (OC): group of stars within a galaxy apparently formed by a single cloud
- turn-off point (TO): point in H-R diagram of a cluster where stars turn red
blue supergiant:
- B-type star (B): star with spectral characteristics of around 10000-30000 K
- supergiant: very large giant star
BMBF:
- Astronet: European astronomy consortium
BMP:
- binary minor planet (BMP): minor planet with another body orbiting it
BNS:
- binary neutron star (BNS,NSB,DNS): two neutron stars co-orbiting
Bochum:
- rare designator prefixes: designator prefixes generally used for only a few objects
Bode designation:
- Flamsteed designation: star designation system dating from 1700s
Bode's law:
- Titius-Bode law: relationship between the distances between solar system planets
body:
- astronomical object: planet, star, galaxy, etc.
Bohr model: has electrons circling nucleus in quantized orbits
Bohr model of the atom:
- Bohr model: has electrons circling nucleus in quantized orbits
Bohr radius:
- Bohr model: has electrons circling nucleus in quantized orbits
boil off:
- Jeans escape: type of ongoing escape of gas particles from atmosphere
Bok:
- rare designator prefixes: designator prefixes generally used for only a few objects
Bok globule: dense molecular cloud
Bol'shoi Teleskop Azimultal'nyi:
- Large Altazimuth Telescope (BTA-6): 6-meter reflector telescope in Russia
Bolocam:
- Caltech Submillimeter Observatory (CSO): 10.4 meter submillimeter telescope in Hawaii
Bologna Sky Survey:
- Bologna Survey of Radio Sources: 1970s-1980s radio survey
Bologna Survey:
- Bologna Survey of Radio Sources: 1970s-1980s radio survey
Bologna Survey of Radio Sources: 1970s-1980s radio survey
bolometer: instrument measuring heat produced by radiation
- GISMO: 2 mm bolometer camera on IRAM 30 m telescope
- MUSTANG: bolometer array on the Green Bank Telescope
- SCUBA: submillimeter instrument on James Clark Maxwell Telescope
bolometers:
- ACBAR: instrument used in CMB search
bolometric:
- bolometer: instrument measuring heat produced by radiation
bolometric correction: difference between an object's bolometric and visible magnitudes
bolometric luminosity (L_Bol): total luminosity of an object at all wavelengths
bolometric magnitude (Mbol,M_bol): absolute magnitude of all wavelengths
Bolshoi simulation: cosmological simulation
Boltzmann code:
- CMBFAST: software to calculate CMB anisotropies
Boltzmann constant (k,k_B): relates particle energy and temperature
Boltzmann distribution:
- Boltzmann equation: equation relating atomic excitation to temperature
Boltzmann equation: equation relating atomic excitation to temperature
- CMBFAST: software to calculate CMB anisotropies
- degeneracy weight: number of quantum states with same energy level
- stellar dynamics: stars' gravitational interaction
Boltzmann factor:
- Boltzmann equation: equation relating atomic excitation to temperature
- partition function (Z): scale factor for Boltzmann factors
Boltzmann relation:
- Boltzmann equation: equation relating atomic excitation to temperature
Boltzmann solver:
- CMBFAST: software to calculate CMB anisotropies
Boltzmann transport equation:
- Boltzmann equation: equation relating atomic excitation to temperature
- Boltzmann Transport Equation (BTE): equation for evolving distribution of gas particles
- CMBFAST: software to calculate CMB anisotropies
- Vlasov-Poisson equation: equation describing plasma ignoring the magnetic field
Boltzmann_equation:
- Boltzmann Transport Equation (BTE): equation for evolving distribution of gas particles
Bond:
- hydrocarbon (HC): any compound of just carbon and hydrogen
- rare designator prefixes: designator prefixes generally used for only a few objects
Bondi accretion:
- Bondi radius: radius within which a body moving through a medium will draw it in
Bondi radius: radius within which a body moving through a medium will draw it in
bone:
- filament: linear volume of high molecular gas density within a galaxy
Bonner Durchmusterung Catalog (BD): well-known astrometric catalog from late 1800s
BOOM01:
- BOOMERanG: 1990s-2000s balloon-borne 1.3-meter millimeter telescope
BOOM05:
- BOOMERanG: 1990s-2000s balloon-borne 1.3-meter millimeter telescope
BOOMERanG: 1990s-2000s balloon-borne 1.3-meter millimeter telescope
BOOMERanG 2005:
- BOOMERanG: 1990s-2000s balloon-borne 1.3-meter millimeter telescope
born again star:
- asymptotic giant branch (AGB): a second stage of helium burning in some stars
Bose-Einstein condensate (BEC): rare state of matter possible at cryogenic temperatures
Bose-Einstein distribution:
- Bose-Einstein statistics: possible distribution of particles not bound by Pauli exclusion
Bose-Einstein statistics: possible distribution of particles not bound by Pauli exclusion
boson:
- Bose-Einstein statistics: possible distribution of particles not bound by Pauli exclusion
- electron degeneracy: electrons set free of atoms by the Pauli exclusion principle
- exotic star: term for theoretical stars not made of atoms/ions
- pair production: creation of a particle/antiparticle pair
- particle: very small thing
- Pauli exclusion principle: fermions in a quantum system cannot have identical quantum numbers
- photon: quantum of light, i.e., light as a particle
- spin (m_s): an angular-momentum quantum number
boson star:
- exotic star: term for theoretical stars not made of atoms/ions
BOSS:
- Baryon Oscillation Spectroscopic Survey (BOSS): survey of spatial distribution of luminous red galaxies and quasars
- Sloan Digital Sky Survey (SDSS): imaging survey of 500,000,000 objects in 35% of sky
BOSS Spectrograph:
- Sloan 2.5m Telescope: telescope for SDSS in New Mexico
bottom quark:
- particle: very small thing
- standard model: model of elementary particles including quarks
Bouguer anomaly: effect of terrain on gravity measurement on a planet's surface
Bouguer correction:
- Bouguer anomaly: effect of terrain on gravity measurement on a planet's surface
Bouguer reduction:
- Bouguer anomaly: effect of terrain on gravity measurement on a planet's surface
bouncing barrier: the problem that the seeds of planets would rebound rather than merge
- barrier: challenging issue regarding planet formation
- meter size barrier: a barrier to planet formation on the order of a meter diameter
bound GMC:
- giant molecular cloud (GMC): interstellar gas cloud with molecules, thousands of solar masses
bound-bound:
- absorption: removal of photons from a beam of EMR
- atomic excitation: atoms with electrons above the ground state
bound-free:
- absorption: removal of photons from a beam of EMR
- Kramers opacity law: opacity's relation to density and temperature
- photoionization: photon striking neutral atom expelling an electron
boundary condition:
- stellar structure: the presumed internal structure of stars
bow shock: shock wave of a magnetosphere through the surrounding medium
Boyajian's Star:
- KIC 8462852: star with unusual variations
Boyden Observatory 1.5 m telescope:
- Microlensing Planet Search (MPS): program to follow up on microlensing detections
Boyle's law:
- equation of state (EoS): equation relating temperature, pressure, and volume
- statistical mechanics: mechanical behavior based upon probability
BP Crucis:
- hypergiant: extremely bright stars
BP process:
- Blandford-Payne mechanism (BP process): means of extracting BH rotational energy by magnetized accretion disk
Bp star:
- Ap star: peculiar type of A star
- chemically peculiar star (CP star): star with SED showing presence metals unusual for stars
Bp-Ap:
- chemically peculiar star (CP star): star with SED showing presence metals unusual for stars
BP/RP:
- Gaia: 2010s astrometry survey satellite
BPI:
- rare designator prefixes: designator prefixes generally used for only a few objects
BPM:
- Bruce Proper Motion Survey (BPM): 1941 southern-hemisphere survey catalog of Luyten's
- rare designator prefixes: designator prefixes generally used for only a few objects
BPMA:
- rare designator prefixes: designator prefixes generally used for only a few objects
BPS:
- rare designator prefixes: designator prefixes generally used for only a few objects
- stellar population synthesis (SPS): using spectral characteristics of galaxies to characterize their stellar populations
BR:
- rare designator prefixes: designator prefixes generally used for only a few objects
bracket notation:
- metallicity (Z): metal fraction of an object
Brackett:
- Brackett series: hydrogen lines for electrons settling from n > 4 to n = 4
Brackett series: hydrogen lines for electrons settling from n > 4 to n = 4
Bradley:
- rare designator prefixes: designator prefixes generally used for only a few objects
break-up velocity:
- stellar rotation: rotation of a star around an axis through the middle
breaking a degeneracy:
- degeneracy: general word meaning a violation of normal rules
breaking atmospheric wave:
- internal gravity wave: ripples in a change in density in a fluid
breaking radiation:
- bremsstrahlung: photon emission when a charged particle is decelerated
Breakthrough Initiatives:
- Breakthrough Listen (BL): SETI survey using GBT and Parkes Observatory
- Starshot: plan for mission to fly by Alpha Centauri
Breakthrough Listen (BL): SETI survey using GBT and Parkes Observatory
Breakthrough Starshot:
- Starshot: plan for mission to fly by Alpha Centauri
bremsstrahlung: photon emission when a charged particle is decelerated
- electron scattering: any process that changes the course of an electron
- spectral index (α): power by which an object's flux depends on frequency
- Thermal Bremsstrahlung: type of EMR produced by thin, hot plasma
bremsstrahlung cooling:
- Thermal Bremsstrahlung: type of EMR produced by thin, hot plasma
bremsstrahlung self-absorption:
- Thermal Bremsstrahlung: type of EMR produced by thin, hot plasma
Brey:
- rare designator prefixes: designator prefixes generally used for only a few objects
BRI:
- rare designator prefixes: designator prefixes generally used for only a few objects
bright giant:
- giant star: star larger than main sequence stars
- luminosity class: classification of size/luminosity of stars
- supergiant: very large giant star
bright nebula:
- cloud: higher-density region of space
- nebula: cloud of dust and gas
bright star:
- Achernar: ninth-brightest star in the sky
- Alpha Centauri: nearest star system
- Arcturus: fourth brightest star in the sky
- Beta Centauri: second brightest star in Centaurus
- Betelgeuse: second brightest star in constellation Orion
- Canopus: second brightest star in the sky
- Epsilon Eridani: third nearest visible star system in sky
- Procyon: brightest star in Canis Minor
- Rigel: brightest star in constellation Orion
- Sirius: brightest star in the sky
- Vega: brightest star in constellation Lyra
Bright Star Catalog (HR,BS,YBS): early 20th century catalog of 9000 stars
bright supergiant:
- supergiant: very large giant star
brightest cluster galaxy (BCG): a cluster's most luminous galaxy
brightest star:
- planetary nebula luminosity function (PNLF): model used in distance estimation
brightness:
- AB system: monochromatic magnitude calibration based upon absolute values
- absolute magnitude (M): magnitude as would be seen from 10 parsecs
- apparent magnitude (m): magnitude as seen from Earth adjusted for Earth atmosphere
- bolometric magnitude (Mbol,M_bol): absolute magnitude of all wavelengths
- K correction: correction to magnitude for redshift
- magnitude: a logarithmic measure of brightness
- Vega system: magnitude calibration such that Vega has zero magnitude
brightness temperature (T_B): temperature of an equivalent black body in terms of intensity
- effective temperature (T_eff,Teff): temperature of an equivalent black body in terms of total radiation
- temperature: measure of heat in matter
British:
- United Kingdom Infrared Telescope (UKIRT): Mauna Kea 3.8 meter infrared telescope
British Columbia:
- Canadian Hydrogen Intensity Mapping Experiment (CHIME,CH): radio telescope mapping distant neutral hydrogen
- Dominion Observatory 10.03 MHz Source Catalog (DB): 1960s survey of northern-hemisphere radio sources
- Dominion Observatory 1420 MHz Source Catalog (DA): 1960s survey of northern-hemisphere radio sources
- Dominion Radio Astrophysical Observatory (DRAO): radio observatory in British Columbia, Canada
- Large Zenith Telescope (LZT): 6 meter liquid mirror telescope in British Columbia
broad band photometry:
- photometry: studying starlight through bandpass filters
broad emission line cloud:
- broad emission line region: region within an AGN with broad emission lines
broad emission line region: region within an AGN with broad emission lines
broad emission-line region:
- broad-line region (BLR): region in center of active galaxy where spectral lines are broad
broad-line AGN:
- Seyfert galaxy: visible active galaxy
broad-line region (BLR): region in center of active galaxy where spectral lines are broad
- Seyfert galaxy: visible active galaxy
broad-line region cloud:
- broad-line region (BLR): region in center of active galaxy where spectral lines are broad
broadband:
- bandwidth: number of hertz between minimum and maximum frequencies
broadening:
- line broadening: processes causing a spectral line to have width
broadening function:
- Voigt profile: mathematical shape that models spectral lines
brown dwarf (BD): star-like object with less mass than a star
- Epsilon Indi (ε Indi,ε Ind): nearby star system including two brown dwarf companions
- Luhman 16: nearby binary brown dwarf
- Scholz's Star: nearby binary star with red dwarf and brown dwarf
- WISE 0855-0714: nearby brown dwarf
- WISE 1506+7027: nearby brown dwarf
brown dwarfs:
- CFBDS: survey in search of brown dwarfs
- CTIO Upper-Scorpius OB Association Survey (UScoCTIO): survey of low-mass stars and brown dwarfs
- L-type star (L): spectral type of star cooler than an M-type star
- substellar object: star-like object with less mass than a star
- T-type star (T): brown dwarf with a temperature in the vicinity of 1000 K
- Y-type star (Y): brown dwarf with a temperature less than 700 K
Brown noise:
- red noise: noise tending toward lower frequencies
Brownian motion:
- red noise: noise tending toward lower frequencies
Brownian noise:
- red noise: noise tending toward lower frequencies
BrsO:
- rare designator prefixes: designator prefixes generally used for only a few objects
BRT:
- rare designator prefixes: designator prefixes generally used for only a few objects
Bruce Proper Motion Survey (BPM): 1941 southern-hemisphere survey catalog of Luyten's
Brunt-Väisälä frequency: natural frequency of buoyancy waves
brute force:
- finite difference method (FDM): means of estimating calculus and differential equation solutions
BS:
- Bright Star Catalog (HR,BS,YBS): early 20th century catalog of 9000 stars
- open cluster (OC): group of stars within a galaxy apparently formed by a single cloud
- turn-off point (TO): point in H-R diagram of a cluster where stars turn red
BSC:
- Bright Star Catalog (HR,BS,YBS): early 20th century catalog of 9000 stars
BSE:
- bulk silicate earth (BSE): the early overall composition of the silicate part of Earth
BSG:
- supergiant: very large giant star
BSMBH:
- binary SMBH (BSMBH,SMBBH,SMBHB): co-orbiting supermassive black holes
BSO:
- rare designator prefixes: designator prefixes generally used for only a few objects
BSS:
- Catalina Sky Survey (CSS): survey of near-Earth objects
- open cluster (OC): group of stars within a galaxy apparently formed by a single cloud
- turn-off point (TO): point in H-R diagram of a cluster where stars turn red
BT-Settl: model atmosphere of small stars and brown dwarfs
BTA-6:
- Large Altazimuth Telescope (BTA-6): 6-meter reflector telescope in Russia
BTE:
- Boltzmann equation: equation relating atomic excitation to temperature
- Boltzmann Transport Equation (BTE): equation for evolving distribution of gas particles
- CMBFAST: software to calculate CMB anisotropies
BTFR:
- Tully-Fisher relation (TFR): relation between spiral galaxy luminosity and line width
Btz:
- rare designator prefixes: designator prefixes generally used for only a few objects
BU:
- Burnham Double Star Catalogue (BDS,BU): 1906 catalog with multiple star systems and non-orbiting double stars
bubble:
- Local Bubble: ISM shell in which the solar system resides
- shell: hollow shaped region of some kind of ISM
buckminsterfullerene:
- diffuse interstellar bands (DIBs): type of absorption bands seen in astronomical objects
- polycyclic aromatic hydrocarbon (PAH): hydrocarbons consisting of meshes of benzene rings
bucky ball:
- polycyclic aromatic hydrocarbon (PAH): hydrocarbons consisting of meshes of benzene rings
bulge: denser group of stars within a larger group
- stellar dynamics: stars' gravitational interaction
bulk atmosphere:
- atmosphere: gas surrounding astronomical object
bulk density: total mass divided by total volume
bulk metallicity:
- metallicity (Z): metal fraction of an object
bulk modulus:
- sound speed: speed at which compression waves traverse a gas
bulk planetary atmosphere:
- atmosphere: gas surrounding astronomical object
bulk silicate earth (BSE): the early overall composition of the silicate part of Earth
Bullet Cluster: example of two galaxy clusters in collision
- dark matter: matter suggested by gravity in galaxies and galaxy clusters
buoyancy frequency:
- Brunt-Väisälä frequency: natural frequency of buoyancy waves
BUP:
- rare designator prefixes: designator prefixes generally used for only a few objects
Burnham:
- Burnham Double Star Catalogue (BDS,BU): 1906 catalog with multiple star systems and non-orbiting double stars
Burnham Double Star Catalogue (BDS,BU): 1906 catalog with multiple star systems and non-orbiting double stars
burning:
- fusion: formation of an atomic nucleus nuclei from multiple smaller nuclei
burst:
- gravitational-wave memory: a gravitational wave that does not return
burst gravitational wave:
- gravitational-wave memory: a gravitational wave that does not return
BV:
- rare designator prefixes: designator prefixes generally used for only a few objects
BVD:
- rare designator prefixes: designator prefixes generally used for only a few objects
BVIT:
- Southern African Large Telescope (SALT): 10 meter telescope in South Africa
BWE:
- Becker, White, and Edwards Catalog (BWE): 1990s radio catalog from a Green Bank 300ft Telescope survey
BY:
- variable star: star that varies in magnitude
BY Draconis star:
- variable star: star that varies in magnitude
BY Draconis variable:
- variable star: star that varies in magnitude
BYORP:
- Yarkovsky-O'Keefe-Radzievskii-Paddack effect (YORP): rotational effect on asymmetric asteroids
Byurakan Observatory:
- Second Byurakan Survey (SBS): 1970s-1990s survey of galaxies and quasars
BZ:
- Roma-BZCAT: 2008 catalog of blazars
BZ process:
- Blandford-Znajek mechanism (BZ process): means of extracting BH rotational energy by magnetized accretion disk
BZB:
- Roma-BZCAT: 2008 catalog of blazars
BZQ:
- Roma-BZCAT: 2008 catalog of blazars
BZU:
- Roma-BZCAT: 2008 catalog of blazars

Index