| Subject |
has right ascension |
has declination |
has spectral type |
is part of |
has surface temperature |
is an instance of |
has V magnitude |
has color |
has been observ |
has symbol |
has B-V magnitude |
has distance |
has absorption line |
is usually part of |
is a kind of |
has apparent magnitude |
has synonym |
has definition |
has luminosity class |
|---|
| A star | | | O, B, A, and early F | | 10000 K | | | white | | | | | H I | | early star | | | Star with spectral type A in which the spectrum of the Balmer lines of hydrogen attain their greatest strength. Helium lines can no longer be seen. Some metallic lines are present; in late A stars the H and K lines of ionized calcium appear. A0 stars have a color index of zero. | |
| 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 |
| naked eye star | | | | Milky Way | greater than 1000 Kelvin | | | | for many centuries | | | | | asterism | naked eye object | brighter than 5 | | A star visible without visual aids | |
| Altair | 19 50 46.9 | +08 52 06 | A7 V | Milky Way | 10000 K | naked eye star | 0.77 | white | for many centuries | d | 0.22 | 4.8 pc | H I | asterism | | mv = 0.78 | HR 7557 | A bright A7 V star. | V |
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