Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Cetus |
Right ascension | 00h 14m 38.41655s[2] |
Declination | −18° 55′ 58.3145″[2] |
Apparent magnitude (V) | 4.44[3] (4.26–4.46)[4] |
Characteristics | |
Spectral type | M1 III[5] |
B−V color index | 1.640±0.044[3] |
Variable type | LB:[4] |
Astrometry | |
Radial velocity (Rv) | −22.9±1.0[6] km/s |
Proper motion (μ) | RA: −26.15[2] mas/yr Dec.: −73.58[2] mas/yr |
Parallax (π) | 7.29 ± 0.28 mas[2] |
Distance | 450 ± 20 ly (137 ± 5 pc) |
Absolute magnitude (MV) | –1.24[3] |
Details | |
Radius | 54[7] R☉ |
Luminosity | 1019.14[8] L☉ |
Temperature | 3,800[8] K |
Other designations | |
Database references | |
SIMBAD | data |
7 Ceti is a single,[10] variable star in the equatorial constellation of Cetus. It has the variable star designation AE Ceti.[1] The star is visible to the naked eye with a baseline apparent visual magnitude of 4.44.[3] Based upon an annual parallax shift of only 7.3 mas,[2] it is located roughly 450 light years away. It is moving closer to the Sun with a heliocentric radial velocity of −23 km/s.[6] Eggen (1965) listed it as a probable member of the Wolf 630 group of co-moving stars.[11]
This is an aging red giant star with a stellar classification of M1 III,[5] currently on the asymptotic giant branch.[12] Samus et al. (2017) has it classed as a slow irregular variable of type LB:, and ranges in magnitude from 4.26 down to 4.46.[4] Tabur et al. (2009) list it as a semiregular variable with four known periods ranging in frequency from 19.2 to 41.7 days.[1] The stellar atmosphere of 7 Ceti has expanded to an estimated 54[7] times the Sun's radius. It is radiating around 1,019[8] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,800 K.[8]
Period (Days) |
Amplitude (Mag.) |
---|---|
19.2 | 0.018 |
19.6 | 0.020 |
27.1 | 0.018 |
41.7 | 0.017 |
Tabur2009
was invoked but never defined (see the help page).vanLeeuwen2007
was invoked but never defined (see the help page).Anderson2012
was invoked but never defined (see the help page).Samus2017
was invoked but never defined (see the help page).houk1978
was invoked but never defined (see the help page).deBruijne2012
was invoked but never defined (see the help page).Fracassini2001
was invoked but never defined (see the help page).McDonald2012
was invoked but never defined (see the help page).SIMBAD
was invoked but never defined (see the help page).Eggleton2008
was invoked but never defined (see the help page).Eggen1965
was invoked but never defined (see the help page).eggen1992
was invoked but never defined (see the help page).