Theta2 Orionis Comparison Table

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Theta2 Orionis comparison table

Subject has spectral type is part of has surface temperature has orbital period is an instance of has rotation velocity has color has symbol has absorption line has relative abundance has abundance has lifetime is a kind of has synonym has definition has luminosity class has number of star

dwarf greater than 1000 Kelvin 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

O star O, B, A, and early F 35000 K very high blue-white He II rare 3 to 6 million years early star Very hot blue star, whose spectra is dominated by the lines of singly ionized helium (see Pickering series). (Most other lines are from at least doubly ionized elements, though H and He I lines are also present.) O stars are useful because they are found in dust clouds and virtually define the spiral arms.

spectroscopic binary greater than 1000 Kelvin half the stars in the solar neighborhood are members of star systems binary star Star whose binary nature can be detected from the periodic Doppler shifts of their spectra, owing to their varying velocities in the line of sight. Double-lined spectroscopic binaries have two sets of spectral features, oscillating with opposite phases. Single-lined spectroscopic binaries have only one set of oscillating spectral lines, owing to the dimness of the secondary component. Spectroscopic binaries are typically of spectral type B, with almost circular orbits (whereas long-period M-type binaries have highly eccentric orbits). 2

Theta2 Orionis O9.5 Vp Orion 35000 K 21.03 days dwarf very high blue-white d He II rare half the stars in the solar neighborhood are members of star systems 3 to 6 million years 2U 0525-06 A spectroscopic binary tentatively identified with 2U 0525-06. V 2

Subject	has spectral type	is part of	has surface temperature	has orbital period	is an instance of	has rotation velocity	has color	has symbol	has absorption line	has relative abundance	has abundance	has lifetime	is a kind of	has synonym	has definition	has luminosity class	has number of star
dwarf			greater than 1000 Kelvin					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
O star	O, B, A, and early F		35000 K			very high	blue-white		He II	rare		3 to 6 million years	early star		Very hot blue star, whose spectra is dominated by the lines of singly ionized helium (see Pickering series). (Most other lines are from at least doubly ionized elements, though H and He I lines are also present.) O stars are useful because they are found in dust clouds and virtually define the spiral arms.
spectroscopic binary			greater than 1000 Kelvin								half the stars in the solar neighborhood are members of star systems		binary star		Star whose binary nature can be detected from the periodic Doppler shifts of their spectra, owing to their varying velocities in the line of sight. Double-lined spectroscopic binaries have two sets of spectral features, oscillating with opposite phases. Single-lined spectroscopic binaries have only one set of oscillating spectral lines, owing to the dimness of the secondary component. Spectroscopic binaries are typically of spectral type B, with almost circular orbits (whereas long-period M-type binaries have highly eccentric orbits).		2
Theta2 Orionis	O9.5 Vp	Orion	35000 K	21.03 days	dwarf	very high	blue-white	d	He II	rare	half the stars in the solar neighborhood are members of star systems	3 to 6 million years		2U 0525-06	A spectroscopic binary tentatively identified with 2U 0525-06.	V	2

Next dwarf: UV Ceti star Up: dwarf, O star, spectroscopic binary Previous dwarf: Sun