HD 4391
Triple star system in the constellation of Phoenix
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HD 4391 is a quadruple star system[10] in the constellation Phoenix that is located at a distance of 49.1 light years from the Sun. The primary has a stellar classification of G3V, which is a G-type main sequence star. The physical properties of this star are similar to the Sun, making it a solar analog. However, it is believed to have 6% greater mass than the Sun[6] and is only 800 million years old.[7] The spectrum for this star displays an abnormally low level of beryllium, which may be the result of some form of mixing process.[8]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Phoenix[1] |
| Right ascension | 00h 45m 45.5929s[2] |
| Declination | −47° 33′ 07.143″[2] |
| Apparent magnitude (V) | 5.80[3] |
| Characteristics | |
| A | |
| Evolutionary stage | main sequence[2] |
| Spectral type | G3V[4] |
| B−V color index | +0.64[3] |
| Astrometry | |
| A | |
| Radial velocity (Rv) | −11.4[5] km/s |
| Proper motion (μ) | RA: +183.635[2] mas/yr Dec.: +79.015[2] mas/yr |
| Parallax (π) | 66.4509±0.0446 mas[2] |
| Distance | 49.08 ± 0.03 ly (15.05 ± 0.01 pc) |
| Absolute magnitude (MV) | +4.90[1] |
| Details | |
| A | |
| Mass | 1.08[6] M☉ |
| Radius | 0.92[6] R☉ |
| Luminosity | 0.92[6] L☉ |
| Surface gravity (log g) | 4.55[6] cgs |
| Temperature | 5,916[6] K |
| Metallicity [Fe/H] | −0.06[7] dex |
| Rotation | 12 days[8] |
| Rotational velocity (v sin i) | 3.5[4] km/s |
| Age | 800[7] Myr |
| Other designations | |
| CD−48 176, HD 4391, GJ 1021, HIP 3583, HR 209, SAO 215232[9] | |
| Database references | |
| SIMBAD | data |
No planet has been detected in orbit around this star,[11] nor does it emit a statistically significant excess of infrared radiation that might indicate a debris disk.[12] However, it has three companions that share a common proper motion through space with HD 4391, effectively making it a quadruple star system. HD 4391 B, a pair of red dwarfs of combined spectrum M4, lies at an angular separation of 17″ from the primary, with the two components designated Ba and Bb. HD 4391 C is a type M5 star at a separation of 49″.[13][10] The close red dwarf pair are also sometimes designated HD 4391 B and HD 4391 C, with the outer component being named HD 4391 D.[14][15]