Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Eridanus [1] |
Right ascension | 02h 39m 47.96544s [2] |
Declination | −42° 53′ 30.3638″ [2] |
Apparent magnitude (V) | +4.74 [3] |
Characteristics | |
Spectral type | A1 Vb [4] + M2-5V [5] + ? |
B−V color index | 0.061±0.003 [3] |
Astrometry | |
Radial velocity (Rv) | +18.0±4.2 [3] km/s |
Proper motion (μ) | RA: +88.20 [6] mas/yr Dec.: −17.82 [6] mas/yr |
Parallax (π) | 24.7076±0.3930 mas [2] |
Distance | 132 ± 2 ly (40.5 ± 0.6 pc) |
Absolute magnitude (MV) | +1.76 [7] |
Details | |
Aa | |
Mass | 1.95 [8] M☉ |
Radius | 1.93 [9] R☉ |
Luminosity | 17.44 [3] L☉ |
Surface gravity (log g) | 4.40±0.14 [8] cgs |
Temperature | 9,099±309 [8] K |
Metallicity [Fe/H] | −0.06 [4] dex |
Rotational velocity (v sin i) | 167.6±1.7 [10] or 13.4±1.5 [7] km/s |
Age | 212 [8] or 30 [9] Myr |
Other designations | |
s Eri, CD−43°814, FK5 2185, HD 16754, HIP 12413, HR 789, SAO 215996 [11] | |
Database references | |
SIMBAD | data |
HD 16754 is a binary [12] or triple-star [9] system in the constellation Eridanus. It has the Bayer designation s Eridani; HD 16754 is the designation from the Henry Draper catalogue . The system is visible to the naked eye as a faint point of light with an apparent visual magnitude of +4.74. [3] It is located at a distance of approximately 132 light years from the Sun based on parallax, [2] and is drifting further away with a radial velocity of +18 km/s. [3] The system is a member of the Columba association of co-moving stars. [13]
This object was flagged as an astrometric binary based on proper motion measurements made from the Hipparcos spacecraft. [14] [15] Zuckerman et al. (2011) consider it a multi-star system, with a bright A-type primary plus a faint M-type companion at an angular separation of 25″ to the north. The astrometric companion to the primary remains unresolved. [9]
The main component is an A-type main-sequence star with a stellar classification of A1 Vb. [4] Based upon stellar models, it has an age estimated at 212 million years. [8] Consistency with its membership in the Columba association suggests a much younger age of 30 million years. [9] Earlier measurements showed a high projected rotational velocity of 168 km/s. [10] However, Ammler-von Eiff and Reiners (2012) found a much lower velocity of 13 km/s. [7]
The visible companion is a red dwarf star with a class in the range M2-5V. The system is a source of X-ray emission with a luminosity of 924×1020 W , which is most likely coming from this component and the unresolved companion. [5]