| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Phoenix |
| Right ascension | 00h 30m 27.825s[2] |
| Declination | −40° 56′ 22.51″[2] |
| Apparent magnitude (V) | 6.18[3] |
| Characteristics | |
| Spectral type | F0/2III[4] |
| Variable type | δ Scuti[3] |
| Astrometry | |
| Radial velocity (Rv) | −3.6[5] km/s |
| Proper motion (μ) | RA: −3.40[2]mas/yr Dec.: 16.95[2]mas/yr |
| Parallax (π) | 7.2816±0.0397 mas[2] |
| Distance | 448 ± 2 ly (137.3 ± 0.7 pc) |
| Absolute magnitude (MV) | 0.57±0.20[6] |
| Details[6] | |
| Mass | 2.25±0.10 M☉ |
| Radius | 4.7±0.3 R☉ |
| Luminosity | 55.2+5.4 −9.3 L☉ |
| Surface gravity (log g) | 3.44±0.03 cgs |
| Temperature | 7,200±100 K |
| Rotation | 2.17 days |
| Rotational velocity (v sin i) | 82±2 km/s |
| Other designations | |
| BB Phe,CD−41°116,HD 2724,HIP 2388,HR 119,SAO 215120[7] | |
| Database references | |
| SIMBAD | data |
BB Phoenicis is avariable star in theconstellation ofPhoenix. It has an average visualapparent magnitude of 6.17,[3] being visible to thenaked eye with excellent viewing conditions. Fromparallax measurements by theGaia spacecraft, it is located at a distance of 448light-years (137parsecs) from Earth.[2] Itsabsolute magnitude is calculated at 0.6.[6]
BB Phoenicis is aDelta Scuti variable, and showsstellar pulsations that cause brightness variations with an amplitude of 0.04 magnitudes.[3] Its variability was discovered by accident in 1981, when the star was used as a comparison star for the eclipsing binary AG Phoenicis.[8] Photometric and spectroscopic data have allowed the detection of at least 13 modes of radial and non-radial pulsations, the strongest one having a period of 0.174 days and an amplitude of 11.1 milli-magnitudes. Observations in different epochs show evidence that the pulsations modes vary in amplitude, which is common among Delta Scuti variables. Pulsation models indicate that the stellar rotation axis is inclined by 50–70° in relation to the line of sight.[9]
This star is classified as an F-typegiant with aspectral type of F0/2III.[4] It appears to be expanding after depleting all the nuclear hydrogen and leaving themain sequence.[6] BB Phoenicis has an estimated mass of 2.25 times thesolar mass and a radius of 4.7 times thesolar radius. It is radiating 55 times theSun's luminosity from itsphotosphere at aneffective temperature of 7,200 K.[6]
