| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Equuleus |
| A | |
| Right ascension | 21h 18m 34.85s[1] |
| Declination | +11° 34′ 08.2″[1] |
| Apparent magnitude (V) | 7.25±0.03[2] |
| B | |
| Right ascension | 21h 18m 34.80s[1] |
| Declination | +11° 34′ 08.0″[1] |
| Apparent magnitude (V) | 8.87±0.14[2] |
| Characteristics | |
| Spectral type | G0 V (combined)[3] |
| U−B color index | +0.07[4] |
| B−V color index | +0.56[4] |
| Aa | |
| Spectral type | F9 V[5] or G1 V[6] |
| Ab | |
| Spectral type | G0 V[5] or G2 V[6] |
| B | |
| Spectral type | G1.5 V[5] or G6 V[7] |
| Astrometry | |
| Radial velocity (Rv) | 6.24±0.04[8] km/s |
| Proper motion (μ) | RA: +29.213 mas/yr[9] Dec.: −49.564 mas/yr[9] |
| Parallax (π) | 19.3447 ± 0.0543 mas[9] |
| Distance | 168.6 ± 0.5 ly (51.7 ± 0.1 pc) |
| A | |
| Absolute magnitude (MV) | +3.73±0.13[2] |
| B | |
| Absolute magnitude (MV) | +5.35±0.19[2] |
| Orbit[10] | |
| Primary | A |
| Companion | B |
| Period (P) | 28,685±173 d |
| Semi-major axis (a) | 0.5177±0.0046″ |
| Eccentricity (e) | 0.8651±0.0008 |
| Inclination (i) | 100.36±0.16° |
| Longitude of the node (Ω) | 255.03±0.17° |
| Periastron epoch (T) | 24,468,123±3 JD |
| Argument of periastron (ω) (secondary) | 171.9±0.3° |
| Semi-amplitude (K1) (primary) | 6.13±0.07 km/s |
| Semi-amplitude (K2) (secondary) | 13.95±0.09 km/s |
| Orbit[10] | |
| Primary | Aa |
| Companion | Ab |
| Period (P) | 3.9660465±0.0000015 d |
| Eccentricity (e) | 0.0033±0.0008 |
| Argument of periastron (ω) (secondary) | 271±13° |
| Semi-amplitude (K1) (primary) | 66.03±0.06 km/s |
| Semi-amplitude (K2) (secondary) | 69.69±0.06 km/s |
| Details | |
| The System | |
| Metallicity [Fe/H] | −0.04[11] dex |
| Age | 6.4±0.7[12] Gyr |
| The A Subystem | |
| Temperature | 6,100±150[13] K |
| Rotational velocity (v sin i) | 10[14] km/s |
| Aa | |
| Mass | 1.14[15] M☉ |
| Radius | 1.06±0.08[13] R☉ |
| Luminosity | 1.41+0.15 −0.14[13] L☉ |
| Ab | |
| Mass | 1.08[15] M☉ |
| Radius | 0.97±0.08[13] R☉ |
| Luminosity | 1.16+0.13 −0.11[13] L☉ |
| B | |
| Mass | 0.97[15] M☉ |
| Radius | 0.91±0.08[13] R☉ |
| Luminosity | 0.84+0.09 −0.08[13] L☉ |
| Temperature | 5,703±1,090[2] K |
| Rotational velocity (v sin i) | 9[14] km/s |
| Other designations | |
| Database references | |
| SIMBAD | The system |
| A | |
| B | |
HD 202908, also known as HIP 105200, is a triple star located in the equatorial constellation Equuleus. It has an apparent magnitude of 7.01,[17] making it readily visible in binoculars but not to the naked eye. When resolved, the components have apparent magnitudes of 7.25 and 8.87 respectively.[2] The system is located relatively close at a distance of 169 light years based on Gaia DR3 parallax measurements[9] but it is receding with a heliocentric radial velocity of 6.24 km/s.[8]
Mason2001 was invoked but never defined (see the help page).ten Brummelaar2000 was invoked but never defined (see the help page).Abt1981 was invoked but never defined (see the help page).Mermilliod1986 was invoked but never defined (see the help page).Fekel1981 was invoked but never defined (see the help page).Docobo2006 was invoked but never defined (see the help page).Christy1969 was invoked but never defined (see the help page).Karataş2004 was invoked but never defined (see the help page).GaiaDR3 was invoked but never defined (see the help page).Fekel1997 was invoked but never defined (see the help page).Casagrande2011 was invoked but never defined (see the help page).Holmberg2009 was invoked but never defined (see the help page).Torres2009 was invoked but never defined (see the help page).Cutispoto2002 was invoked but never defined (see the help page).Tokovinin2014 was invoked but never defined (see the help page).SIMBAD was invoked but never defined (see the help page).Tycho2000 was invoked but never defined (see the help page).