Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Equuleus |
Right ascension | 21h 05m 19.74605s [1] |
Declination | +07° 04′ 09.4729″ [1] |
Apparent magnitude (V) | 8.27 [2] |
Characteristics | |
Spectral type | K6 V [3] |
U−B color index | +1.12 [4] |
B−V color index | +1.21 [4] |
R−I color index | +0.61 [2] |
Astrometry | |
Radial velocity (Rv) | −66.94±0.18 [5] km/s |
Proper motion (μ) |
RA: +78.562
mas/
yr
[1] Dec.: −563.909 mas/ yr [1] |
Parallax (π) | 66.4626 ± 0.0225 mas [1] |
Distance | 49.07 ± 0.02
ly (15.046 ± 0.005 pc) |
Absolute magnitude (MV) | +7.38 [6] |
Details | |
Mass | 0.68±0.01 [7] M☉ |
Radius | 0.689+0.077 −0.050 [8] R☉ |
Luminosity | 0.18 [9] L☉ |
Surface gravity (log g) | 4.67±0.02 [7] cgs |
Temperature | 4,406±73 [10] K |
Metallicity [Fe/H] | +0.05±0.06 [7] dex |
Rotational velocity (v sin i) | 5.1±1.2 [5] km/s |
Age | 6.33 [11] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
ARICNS | data |
HD 200779 (HIP 104092; Gliese 818; LHS 3624) is a solitary star located in the equatorial constellation Equuleus, the foal. It has an apparent magnitude of 8.27, [2] making it readily visible in binoculars but not to the naked eye. The object is located relatively close at a distance of 49 light years based on Gaia DR3 parallax measurements, [1] and it is approaching rapidly with a heliocentric radial velocity of −67 km/s. [5] It is classified as a high proper motion star, [12] with a total proper motion of 569 mas/yr. [1]
At its current distance, HD 200779's brightness is diminished by only six hundredths of a magnitude due to interstellar dust [13] and it has an absolute magnitude of +7.38. [6] HD 200779 is expected to come within 7.76 parsecs (25.3 ly) of the Solar System in roughly 160,000 years. [14]
HD 200779 is an ordinary K-type main-sequence star with a stellar classification of K6 V. [3] It has 68% the mass of the Sun [7] and 69% of its radius. [8] However, it only radiates 18% the luminosity of the Sun [9] from its photosphere at an effective temperature of 4,406 K, [10] giving it an orange hue. It has an iron abundance slightly above solar level at [Fe/H] = +0.05 [7] and it is estimated to be 6.33 billion years old. [11] HD 200779 spins modestly with a projected rotational velocity of 5.1 km/s. [5] The star is generally considered to be chromospherically active. [3]
HD 200779 has two optical companions: a distant 11th magnitude star located 64.6" away and a 9th magnitude star located 169.4" away. [15]
Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Equuleus |
Right ascension | 21h 05m 19.74605s [1] |
Declination | +07° 04′ 09.4729″ [1] |
Apparent magnitude (V) | 8.27 [2] |
Characteristics | |
Spectral type | K6 V [3] |
U−B color index | +1.12 [4] |
B−V color index | +1.21 [4] |
R−I color index | +0.61 [2] |
Astrometry | |
Radial velocity (Rv) | −66.94±0.18 [5] km/s |
Proper motion (μ) |
RA: +78.562
mas/
yr
[1] Dec.: −563.909 mas/ yr [1] |
Parallax (π) | 66.4626 ± 0.0225 mas [1] |
Distance | 49.07 ± 0.02
ly (15.046 ± 0.005 pc) |
Absolute magnitude (MV) | +7.38 [6] |
Details | |
Mass | 0.68±0.01 [7] M☉ |
Radius | 0.689+0.077 −0.050 [8] R☉ |
Luminosity | 0.18 [9] L☉ |
Surface gravity (log g) | 4.67±0.02 [7] cgs |
Temperature | 4,406±73 [10] K |
Metallicity [Fe/H] | +0.05±0.06 [7] dex |
Rotational velocity (v sin i) | 5.1±1.2 [5] km/s |
Age | 6.33 [11] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
ARICNS | data |
HD 200779 (HIP 104092; Gliese 818; LHS 3624) is a solitary star located in the equatorial constellation Equuleus, the foal. It has an apparent magnitude of 8.27, [2] making it readily visible in binoculars but not to the naked eye. The object is located relatively close at a distance of 49 light years based on Gaia DR3 parallax measurements, [1] and it is approaching rapidly with a heliocentric radial velocity of −67 km/s. [5] It is classified as a high proper motion star, [12] with a total proper motion of 569 mas/yr. [1]
At its current distance, HD 200779's brightness is diminished by only six hundredths of a magnitude due to interstellar dust [13] and it has an absolute magnitude of +7.38. [6] HD 200779 is expected to come within 7.76 parsecs (25.3 ly) of the Solar System in roughly 160,000 years. [14]
HD 200779 is an ordinary K-type main-sequence star with a stellar classification of K6 V. [3] It has 68% the mass of the Sun [7] and 69% of its radius. [8] However, it only radiates 18% the luminosity of the Sun [9] from its photosphere at an effective temperature of 4,406 K, [10] giving it an orange hue. It has an iron abundance slightly above solar level at [Fe/H] = +0.05 [7] and it is estimated to be 6.33 billion years old. [11] HD 200779 spins modestly with a projected rotational velocity of 5.1 km/s. [5] The star is generally considered to be chromospherically active. [3]
HD 200779 has two optical companions: a distant 11th magnitude star located 64.6" away and a 9th magnitude star located 169.4" away. [15]