HD 16955

HD 15524
Observation data
Epoch J2000      Equinox J2000
Constellation Aries
Right ascension 02h 43m 51.24421s[1]
Declination +25° 38′ 18.0493″[1]
Apparent magnitude (V) 6.376[2]
Characteristics
Spectral type A3 V[3]
B−V color index 0.089±0.002[4]
Astrometry
Radial velocity (Rv)−10.3±3.1[5] km/s
Proper motion (μ) RA: −4.98±0.70[1] mas/yr
Dec.: +6.04±0.52[1] mas/yr
Parallax (π)9.59 ± 0.76 mas[1]
Distance340 ± 30 ly
(104 ± 8 pc)
Absolute magnitude (MV)+1.18±0.13[2]
Details
HD 16955 A
Mass2.25±0.08[6] M☉
Luminosity26.9+3.3
−2.9[2] L☉
Temperature8,450±164[2] K
Rotational velocity (v sin i)175[7] km/s
Other designations
BD+25° 441, HD 16955, HIP 12744, HR 803, SAO 75539[8]
Database references
SIMBADdata

HD 16955, also known as HR 803, is a double or multiple star. With an apparent visual magnitude of 6.376,[2] is lies at or below the nominal limit for visibility with a typical naked eye. The measured annual parallax shift is 9.59 milliarcseconds, which yields an estimated distance of around 340 light years. The star is moving closer to the Sun with a heliocentric radial velocity of around -10 km/s.[5]

This is an A-type main-sequence star with a stellar classification of A3 V.[3] Hauck et al. (1995) identified this as a Lambda Boötis star with a circumstellar shell,[9] but this now appears to be unlikely.[2] It has 2.25[6] times the mass of the Sun and is spinning rapidly with a projected rotational velocity of 175 km/s.[7] The star is radiating about 27[2] times the Sun's luminosity from its photosphere at an effective temperature of roughly 8,450 K.[2]

HD 16955 has a magnitude 10.36 companion, component B, which is located, as of 2015, at an angular separation of 3.0 arcseconds along a position angle of 19°.[10] This is the likely source for the detected X-ray emission with a luminosity of 262.5×1020 W coming from these coordinates, since A-type stars are not expected to emit X-rays.[11] Component C is a more distant magnitude 12.94 companion located at a separation of 51.10 arcseconds along a position angle of 92°, as of 2015.[10]

  1. ^ a b c d e Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d e f g h Cite error: The named reference Murphy2017 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Cowley1969 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference zorec2012 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Royer2007 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Hauck1995 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Mason2014 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Schroeder2007 was invoked but never defined (see the help page).