Subject |
has spectral type |
is part of |
has surface temperature |
is an instance of |
has rotation velocity |
has rotational velocity |
has color |
has symbol |
has distance |
has absorption line |
has relative abundance |
has lifetime |
is a kind of |
has synonym |
has definition |
has luminosity class |
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. | |
Zeta Ophiuchi | O9.5 V | Ophiuchus | 35000 K | dwarf | very high | 396 km s-1 | blue-white | d | 170 pc | He II | rare | 3 to 6 million years | | main sequence star | A reddened O star (a runaway star from the Sco-Cen association) with a high rotational velocity. It is well known for its strong interstellar absorption lines in the visible part of the spectrum. | V |