HD 16754

This article is about s Eridani. For S Eridani, see 64 Eridani.
HD 16754
Observation data
Epoch J2000      Equinox J2000
Constellation Eridanus
Right ascension 02h 39m 47.96544s[1]
Declination −42° 53′ 30.3638″[1]
Apparent magnitude (V) +4.74[2]
Characteristics
Spectral type A1 Vb[3] + M2-5V[4] + ?
B−V color index 0.061±0.003[2]
Astrometry
Radial velocity (Rv)+18.0±4.2[2] km/s
Proper motion (μ) RA: +88.20[5] mas/yr
Dec.: −17.82[5] mas/yr
Parallax (π)24.7076 ± 0.3930 mas[1]
Distance132 ± 2 ly
(40.5 ± 0.6 pc)
Absolute magnitude (MV)+1.76[6]
Details
Aa
Mass1.95[7] M☉
Radius1.93[8] R☉
Luminosity17.44[2] L☉
Surface gravity (log g)4.40±0.14[7] cgs
Temperature9,099±309[7] K
Metallicity [Fe/H]−0.06[3] dex
Rotational velocity (v sin i)167.6±1.7[9] or 13.4±1.5[6] km/s
Age212[7] or 30[8] Myr
Other designations
s Eri, CD−43°814, FK5 2185, HD 16754, HIP 12413, HR 789, SAO 215996[10]
Database references
SIMBADdata

HD 16754 is a binary[11] or triple-star[8] 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.[2] It is located at a distance of approximately 132 light years from the Sun based on parallax,[1] and is drifting further away with a radial velocity of +18 km/s.[2] The system is a member of the Columba association of co-moving stars.[12]

This object was flagged as an astrometric binary based on proper motion measurements made from the Hipparcos spacecraft.[13][14] 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.[8]

The main component is an A-type main-sequence star with a stellar classification of A1 Vb.[3] Based upon stellar models, it has an age estimated at 212 million years.[7] Consistency with its membership in the Columba association suggests a much younger age of 30 million years.[8] Earlier measurements showed a high projected rotational velocity of 168 km/s.[9] However, Ammler-von Eiff and Reiners (2012) found a much lower velocity of 13 km/s.[6]

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.[4]

  1. ^ a b c d Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Gray2006 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Schröder2007 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference vonEiff2012 was invoked but never defined (see the help page).
  7. ^ a b c d e Cite error: The named reference David2015 was invoked but never defined (see the help page).
  8. ^ a b c d e Cite error: The named reference Zuckerman2011 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Díaz2011 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Elliott2016 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Makarov2005 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Frankowski2007 was invoked but never defined (see the help page).