54 Eridani is a suspected astrometric binary[10] star system located around 400 light years from the Sun in the equatorial constellation of Eridanus. It is visible to the naked eye as a faint, reddish hued star with a baseline apparent visual magnitude of 4.32.[3] The object is moving closer to the Earth with a heliocentric radial velocity of −33 km/s.[3]
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Eridanus |
Right ascension | 04h 40m 26.51159s[2] |
Declination | −19° 40′ 17.3723″[2] |
Apparent magnitude (V) | 4.32[3] |
Characteristics | |
Evolutionary stage | asymptotic giant branch[4] |
Spectral type | M3/4 III[5] |
U−B color index | +1.80[6] |
B−V color index | 1.599±0.021[3] |
Variable type | SRb[7] |
Astrometry | |
Radial velocity (Rv) | −32.9±0.8[3] km/s |
Proper motion (μ) | RA: +29.13[8] mas/yr Dec.: −96.42[8] mas/yr |
Parallax (π) | 8.2063 ± 0.2709 mas[2] |
Distance | 400 ± 10 ly (122 ± 4 pc) |
Absolute magnitude (MV) | −0.93[3] |
Details | |
Radius | 69+12 −6[2] R☉ |
Luminosity | 1,021+33 −38[2] L☉ |
Temperature | 3,915+190 −293[2] K |
Other designations | |
Database references | |
SIMBAD | data |
The visible component is an aging red giant star, currently on the asymptotic giant branch,[4] with a stellar classification of M3/4 III.[5] It is a semiregular variable star of subtype SRb, ranging in magnitude from 4.28 down to 4.36.[7] The star has pulsation periods of 18.8 and 45.5 days, each with an amplitude of 0.019 in magnitude.[1] With the hydrogen at its core exhausted, the star has expanded to around 69[2] times the Sun's radius and it is radiating 1,021[2] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 3,915 K.[2]
It was the second-brightest star in the obsolete constellation of Sceptrum Brandenburgicum after 53 Eridani.