HD 1

This article is about a star in the Henry Draper Catalogue. For other uses, see HD 1 (disambiguation).
HD 1
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cepheus
Right ascension 00h 05m 08.84054s[1]
Declination +67° 50′ 23.9805″[1]
Apparent magnitude (V) 7.42±0.01[2]
Characteristics
Evolutionary stage red giant branch[1][3]
Spectral type G9-K0 IIIa[3]
Astrometry
Radial velocity (Rv)−27.3±0.5[4] km/s
Proper motion (μ) RA: +7.480 mas/yr[1]
Dec.: −5.045 mas/yr[1]
Parallax (π)2.668 ± 0.0485 mas[1]
Distance1,220 ± 20 ly
(375 ± 7 pc)
Absolute magnitude (MV)−0.01[5]
Orbit[6]
Period (P)6.345±0.007 yr
Eccentricity (e)0.488±0.013
Periastron epoch (T)2,452,213±9 JD
Argument of periastron (ω)
(secondary)		224±2.2°
Semi-amplitude (K1)
(primary)		4.35±0.08 km/s
Details
Mass3.0[3] M☉
Radius30[7] R☉
Luminosity226±5[4] L☉
Surface gravity (log g)1.81[8] cgs
Temperature5,844±122[9] K
Metallicity [Fe/H]+0.24[8] dex
Rotational velocity (v sin i)5.6±1.2[3] km/s
Age350[3] Myr
Other designations
AG+67°4, BD+67°1599, HD 1, HIP 422, SAO 10963, GSC 04294-00080[10]
Database references
SIMBADdata

HD 1, also known as HIP 422, is the first star catalogued in the Henry Draper Catalogue. It is located in the northern circumpolar constellation Cepheus and has an apparent magnitude of 7.42,[2] making it readily visible in binoculars, but not to the naked eye. The object is located relatively far away at a distance of 1,220 light years but is approaching the Solar System with a spectroscopic radial velocity of −27.3 km/s.[4]

  1. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Tycho2000 was invoked but never defined (see the help page).
  3. ^ a b c d e Cite error: The named reference Strassmeier2010 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference griffin2009 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Kervella2021 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Anders2019 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference TIC 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).