Subject |
has spectral type |
has surface temperature |
is an instance of |
has optical brightness variation |
has observational problem |
has color |
has symbol |
is a kind of |
has name designated with |
has observable variation time scale |
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 |
G star | cooler than G2 | 5000 to 6000 K | | | | yellowish | | late star | | | | Yellowish star in which the H and K lines of Ca II have become dominant and in which a tremendous profusion of spectral lines of both neutral and ionized metals, particularly iron, begins to show. The Balmer lines of hydrogen are still recognizable. Examples are the Sun and Capella. | |
T Tauri star | cooler than G2 | greater than 1000 Kelvin | | 0.2 magnitudes or greater | some difficulty in distinguishing between various kinds | | | emission line 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 | nebular variable | Also called T Tauri variable, a type of variable star of spectral classification F, G or K (giants above the main sequence on the Hertzsprung-Russell diagram) that loses an appreciable proportion of its mass in its (irregular) more luminous periods, and is thus surrounded by volumes of gas and dust. | |
RW Aurigae | G5e V | 5000 to 6000 K | dwarf | 0.2 magnitudes or greater | some difficulty in distinguishing between various kinds | yellowish | d | | - 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 | nebular variable | A T Tauri star with a strong ultraviolet excess. | V |