  | |
| Observation data EpochJ2000.0 EquinoxJ2000.0 (ICRS) | |
|---|---|
| Constellation | Eridanus |
| Right ascension | 04h 36m 19.141s[1] |
| Declination | −03° 21′ 08.86″[1] |
| Apparent magnitude (V) | +3.930±0.023[2] |
| Characteristics | |
| Spectral type | B1.5 IV[3] |
| U−Bcolor index | −0.879±0.007[2] |
| B−Vcolor index | −0.210±0.009[2] |
| Variable type | SPB andBeta Cephei[4] |
| Astrometry | |
| Radial velocity (Rv) | 14.9[5] km/s |
| Proper motion (μ) | RA: +1.53[1]mas/yr Dec.: −5.01[1]mas/yr |
| Parallax (π) | 4.83±0.19 mas[1] |
| Distance | 680 ± 30 ly (207 ± 8 pc) |
| Absolute magnitude (MV) | −2.84±0.15[3] |
| Details[3] | |
| Mass | 9.3±0.3 M☉ |
| Radius | 6.2±0.5 R☉ |
| Luminosity | 7,943 L☉ |
| Surface gravity (log g) | 3.85±0.05 cgs |
| Temperature | 22,000±250 K |
| Rotational velocity (v sin i) | 26±2 km/s |
| Other designations | |
| ν Eri,BD−03°834,48 Eridani,FK5 169,HD 29248,HIP 21444,HR 1463,SAO 131346[6] | |
| Database references | |
| SIMBAD | data |
Nu Eridani (ν Eri) is astar in theconstellationEridanus. It is visible to thenaked eye with anapparent visual magnitude of 3.93.[2] The distance to this star is roughly 520 light years, based upon an annualparallax shift of 0.00625 arcseconds.[1] If the star were 33 ly (10 pc) from theSun, it would be the brightest star in the night sky with an apparent magnitude of −2.84.[3] (Currently, the brightest star isSirius at magnitude −1.46.)
This is aB-typesubgiant star with astellar classification of B1.5 IV.[3] In 1926, Robert H. Baker announced his discovery that the brightness of Nu Eridani is variable.[8][9] It is ahybrid pulsatorvariable, lying as it does on the overlappinginstability strips forBeta Cephei variables andslowly pulsating B-type stars.[4] The star shows at least fourteen pulsations frequencies, with nine that also display radial velocity variations.[10] It has about nine times themass of the Sun and six times theSun's radius. Nu Eridani shines with 7,943 times thesolar luminosity from itsouter atmosphere at aneffective temperature of 22,000 K.[3]
