star Comparison Table

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star comparison table

Subject has spectral type is part of has acceptance statu has orbital period has frequency is an instance of has optical brightness variation has metallic line strength has light curve has observational problem has author has been observ has spatial velocity has symbol has distance has acronym has abundance is usually part of has amplitude has charge has wavelength is a kind of has hydrogen line strength has apparent magnitude has image has name designated with has observable variation time scale has emission line has synonym has definition has luminosity class obey has number of star

asymptotic branch star star Globular cluster stars, which are found in that part of the HR diagram that connects the top pf the giant tip with the horizontal branch stars.

Beta Pictoris Pictor star 50 light years

binary star half the stars in the solar neighborhood are members of star systems star system A system of two stars orbiting around a common center of gravity. Visual binaries are those whose components can be resolved telescopically (i.e., angular separation > 0'.5) and which have detectable orbital motion. Astrometric binaries are those whose dual nature can be deduced from their variable proper motion; spectroscopic binaries, those whose dual nature can be deduced from their variable radial velocity. At least half of the stars in the solar neighborhood are members of binary (or multiple) systems. (See photometric binaries; optical pairs.) 2

bright giant star II

circumpolar star star Star which never sets, from the viewpoint of an observer on Earth.

composite spectrum star star Object with a spectrum due to superposition of the spectra of two different stars.

Delta Del star star A type of late A-type and early F-type star with very weak Ca II HK lines.

double star star A "system" of two stars that appear - because of coincidental alignment when viewed from Earth - to be close together; it is, however, an optical effect only, and therefore not the same as a binary star system (although until the twentieth century there were few means of distinguishing double and binary stars).

dwarf d star main sequence star Star with mass equal to or less than that of the sun. More generally, any star on or below the main sequence in the Hertzprung-Russell diagram. V

early star O, B, A, and early F star Hot star of spectral types O, B, A, and early F.

emission line star star

field star star Star distributed at random in space and not belonging to any particular star cluster.

fundamental star star Star for which coordinates have been determined to a very high degree of accuracy.

giant star High-luminosity star that lies above the main sequence on the Hertzsprung-Russell diagram. III

HD 141569 Libra star 320 light years

high-velocity star > 100 km s^-1 star Late type stars whose spatial velocities are greater than 100 km s^-1. Other authors prefer the definition, with radial velocities greater than 60 km s^-1.

HR 4796A star

hydrogen-deficient star star weak

late star cooler than G2 star Star with spectral type later than the sun (G2).

low-velocity star star A star whose U, V, and W velocities are all near zero. Such stars have nearly circular orbits around the Galaxy.

manganese star star Star with an anomalously high Mn-Fe ratio, which show deviations from the odd-even effect for phosphorus, gallium, and yttrium.

metal-poor star weak star

metal-rich star strong star CN-strong star Star having metal-to-hydrogen ratios greater than those of the Hyades.

naked eye star Milky Way for many centuries asterism naked eye object brighter than 5 A star visible without visual aids

neutron star dark halo hypothetical inversely proportional to the wavelength MACHO inversely proportional to its momentum massive compact halo object hidden mass Remnant of a star after it has exploded as a supernova. Usually optically dim, a neutron star sends out regular or irregular radio emissions and is therefore also called a pulsar. The density of such a star may be unimaginably great although the diameter is generally around only 10 km; the gravitational and magnetic forces are correspondingly vast. It is called a neutron star because in such density, protons fuse with electrons to form neutrons, of which the star is almost entirely composed. uncertainty principle

old star star Star that, according to contemporary stellar evolution theory, have an age comparable to that of the galaxy to which they belong. This is not an observational definition.

Population I star disk Baade (1944) star disk star Youngest observed stars, like our sun, formed from hydrogen, helium, and a large range of heavier elements (like carbon and oxygen) believed to have been created in the interiors of earlier Population II stars and Population III stars and then blown out into space.

Population II star halo Baade (1944) star halo star Older stars, generally formed towards the centre of a galaxy, containing few heavier elements. The brightest of this Population are red giants.

Population III star Baade (1944) star Star older than Population II stars.

program star star The star being observed or measured, as contrasted with the comparison stars.

radio star star Star with detectable emission at radio wavelengths. They include pulsars, flare stars, some infrared stars, and some X-ray stars.

spectrum variable star Main-sequence Am or Ap stars whose spectra show anomalously strong lines of metals and rare earths which vary in intensity by about 0.1 mag over periods of about 1-25 days. They are characterized by large magnetic fields (10³-10⁴ gauss) at the surface, small variations in light and color, and small projected rotational velocities. These peculiarities are sometimes interpreted in terms of an oblique rotator.

subdwarf sd star Late-type object whose observed color and absolute magnitude place it below the Main Sequence. VI

subgiant star A star whose position on the H-R diagram is intermediate between that of main-sequence stars and normal giants of the same spectral type. IV

supergiant star An extremely luminous star of large diameter and low density. No supergiants are near enough to establish a trigonometric parallax. I

triple star half the stars in the solar neighborhood are members of star systems star system A star system having three stars that revolve around one another. 3

variable 0.2 magnitudes or greater some difficulty in distinguishing between various kinds star
R, S, T, U, V, W, X, Y, or Z and the genitive of the latin constellation name
RR, RS, RT, RU, RV, RW, RX, RY, or RZ and the genitive of the latin constellation name when the single letter designations are exhausted
AA...AZ, BB...BZ, etc. (omitting J), which ends with QQ...QZ and the genitive of the latin constellation namewhen the RR...RZ designations are exhausted
V 335, V 336, etc., when the double letter designations are exhausted
within a period of decades a star whose apparent magnitude varies by at least 0.1 magnitudes in the visible spectrum (a star whose optical brightness variations can be detected by the human eye)

Next celestial body: Universe Up: celestial body Previous celestial body: solar system

Subject	has spectral type	is part of	has acceptance statu	has orbital period	has frequency	is an instance of	has optical brightness variation	has metallic line strength	has light curve	has observational problem	has author	has been observ	has spatial velocity	has symbol	has distance	has acronym	has abundance	is usually part of	has amplitude	has charge	has wavelength	is a kind of	has hydrogen line strength	has apparent magnitude	has image	has name designated with	has observable variation time scale	has emission line	has synonym	has definition	has luminosity class	obey	has number of star
asymptotic branch star																						star								Globular cluster stars, which are found in that part of the HR diagram that connects the top pf the giant tip with the horizontal branch stars.
Beta Pictoris		Pictor				star									50 light years
binary star																	half the stars in the solar neighborhood are members of star systems					star system								A system of two stars orbiting around a common center of gravity. Visual binaries are those whose components can be resolved telescopically (i.e., angular separation > 0'.5) and which have detectable orbital motion. Astrometric binaries are those whose dual nature can be deduced from their variable proper motion; spectroscopic binaries, those whose dual nature can be deduced from their variable radial velocity. At least half of the stars in the solar neighborhood are members of binary (or multiple) systems. (See photometric binaries; optical pairs.)			2
bright giant																						star									II
circumpolar star																						star								Star which never sets, from the viewpoint of an observer on Earth.
composite spectrum star																						star								Object with a spectrum due to superposition of the spectra of two different stars.
Delta Del star																						star								A type of late A-type and early F-type star with very weak Ca II HK lines.
double star																						star								A "system" of two stars that appear - because of coincidental alignment when viewed from Earth - to be close together; it is, however, an optical effect only, and therefore not the same as a binary star system (although until the twentieth century there were few means of distinguishing double and binary stars).
dwarf														d								star							main sequence star	Star with mass equal to or less than that of the sun. More generally, any star on or below the main sequence in the Hertzprung-Russell diagram.	V
early star	O, B, A, and early F																					star								Hot star of spectral types O, B, A, and early F.
emission line star																						star
field star																						star								Star distributed at random in space and not belonging to any particular star cluster.
fundamental star																						star								Star for which coordinates have been determined to a very high degree of accuracy.
giant																						star								High-luminosity star that lies above the main sequence on the Hertzsprung-Russell diagram.	III
HD 141569		Libra				star									320 light years
high-velocity star													> 100 km s^-1									star								Late type stars whose spatial velocities are greater than 100 km s^-1. Other authors prefer the definition, with radial velocities greater than 60 km s^-1.
HR 4796A						star
hydrogen-deficient star																						star	weak
late star	cooler than G2																					star								Star with spectral type later than the sun (G2).
low-velocity star																						star								A star whose U, V, and W velocities are all near zero. Such stars have nearly circular orbits around the Galaxy.
manganese star																						star								Star with an anomalously high Mn-Fe ratio, which show deviations from the odd-even effect for phosphorus, gallium, and yttrium.
metal-poor star								weak														star
metal-rich star								strong														star							CN-strong star	Star having metal-to-hydrogen ratios greater than those of the Hyades.
naked eye star		Milky Way										for many centuries						asterism				naked eye object		brighter than 5						A star visible without visual aids
neutron star		dark halo	hypothetical		inversely proportional to the wavelength											MACHO					inversely proportional to its momentum	massive compact halo object							hidden mass	Remnant of a star after it has exploded as a supernova. Usually optically dim, a neutron star sends out regular or irregular radio emissions and is therefore also called a pulsar. The density of such a star may be unimaginably great although the diameter is generally around only 10 km; the gravitational and magnetic forces are correspondingly vast. It is called a neutron star because in such density, protons fuse with electrons to form neutrons, of which the star is almost entirely composed.		uncertainty principle
old star																						star								Star that, according to contemporary stellar evolution theory, have an age comparable to that of the galaxy to which they belong. This is not an observational definition.
Population I star		disk									Baade (1944)											star							disk star	Youngest observed stars, like our sun, formed from hydrogen, helium, and a large range of heavier elements (like carbon and oxygen) believed to have been created in the interiors of earlier Population II stars and Population III stars and then blown out into space.
Population II star		halo									Baade (1944)											star							halo star	Older stars, generally formed towards the centre of a galaxy, containing few heavier elements. The brightest of this Population are red giants.
Population III star											Baade (1944)											star								Star older than Population II stars.
program star																						star								The star being observed or measured, as contrasted with the comparison stars.
radio star																						star								Star with detectable emission at radio wavelengths. They include pulsars, flare stars, some infrared stars, and some X-ray stars.
spectrum variable																						star								Main-sequence Am or Ap stars whose spectra show anomalously strong lines of metals and rare earths which vary in intensity by about 0.1 mag over periods of about 1-25 days. They are characterized by large magnetic fields (10³-10⁴ gauss) at the surface, small variations in light and color, and small projected rotational velocities. These peculiarities are sometimes interpreted in terms of an oblique rotator.
subdwarf														sd								star								Late-type object whose observed color and absolute magnitude place it below the Main Sequence.	VI
subgiant																						star								A star whose position on the H-R diagram is intermediate between that of main-sequence stars and normal giants of the same spectral type.	IV
supergiant																						star								An extremely luminous star of large diameter and low density. No supergiants are near enough to establish a trigonometric parallax.	I
triple star																	half the stars in the solar neighborhood are members of star systems					star system								A star system having three stars that revolve around one another.			3
variable							0.2 magnitudes or greater			some difficulty in distinguishing between various kinds												star				R, S, T, U, V, W, X, Y, or Z and the genitive of the latin constellation name RR, RS, RT, RU, RV, RW, RX, RY, or RZ and the genitive of the latin constellation name when the single letter designations are exhausted AA...AZ, BB...BZ, etc. (omitting J), which ends with QQ...QZ and the genitive of the latin constellation namewhen the RR...RZ designations are exhausted V 335, V 336, etc., when the double letter designations are exhausted	within a period of decades			a star whose apparent magnitude varies by at least 0.1 magnitudes in the visible spectrum (a star whose optical brightness variations can be detected by the human eye)