Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Ursa Major |
A | |
Right ascension | 10h 22m 10.5619s[1] |
Declination | +41° 13′ 46.310″[1] |
Apparent magnitude (V) | 5.73[2] |
B | |
Right ascension | 10h 22m 14.8721s[3] |
Declination | +41° 14′ 26.514″[3] |
Characteristics | |
Evolutionary stage | Main sequence |
Spectral type | F7V[4] or F8IV[5] |
B−V color index | 0.531±0.003[2] |
Astrometry | |
A | |
Radial velocity (Rv) | −4.35±0.12[2] km/s |
Proper motion (μ) | RA: −120.285(42) mas/yr[1] Dec.: −138.171(50) mas/yr[1] |
Parallax (π) | 25.9334 ± 0.0436 mas[1] |
Distance | 125.8 ± 0.2 ly (38.56 ± 0.06 pc) |
Absolute magnitude (MV) | 2.83[6] |
B | |
Proper motion (μ) | RA: −119.215(647) mas/yr[3] Dec.: −140.390(457) mas/yr[3] |
Parallax (π) | 26.0070 ± 0.4713 mas[3] |
Distance | 125 ± 2 ly (38.5 ± 0.7 pc) |
Details | |
A | |
Mass | 1.37±0.09[7] M☉ |
Radius | 2.16+0.06 −0.01[8] R☉ |
Luminosity | 6.38±0.02[9] L☉ |
Surface gravity (log g) | 4.27±0.05[7] cgs |
Temperature | 6,381±43[7] K |
Metallicity [Fe/H] | 0.30±0.03[7] dex |
Rotation | ~9 days[9] |
Rotational velocity (v sin i) | 9.3[10] km/s |
Age | 8.4[9] Gyr |
B | |
Mass | 0.076[11] M☉ |
Other designations | |
A: HD 89744A | |
B: Gaia DR3 804745827531820288, HD 89744B, 2MASS J10221489+4114266 | |
Database references | |
A | |
SIMBAD | data |
Exoplanet Archive | data |
ARICNS | data |
B | |
SIMBAD | data |
HD 89744 is a star in the northern circumpolar constellation of Ursa Major, positioned about 0.4° due south of the bright star Tania Australis (μ UMa).[13] This object has a yellow-white hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.73.[2] The distance to this star has been measured using the parallax method, which locates it 126 light years from the Sun. It is drifting closer with a radial velocity of −4.4 km/s.[2] There are two known exoplanets orbiting this star.
At various times the star HD 89744 has been assigned a stellar classification of F7V,[4][14] F7IV-V,[15] and F8IV,[5][2] suggesting it is an F-type main-sequence star that is evolving onto the subgiant branch. It is ~8.4[9] billion years old with an inactive chromosphere[15] and is spinning with a projected rotational velocity of 9.3 km/s.[10] The star is 2.16[8] times the size of the Sun with 1.4[7] times the Sun's radius. It is a high metallicity star, showing a greater abundance of heavier elements than in the Sun. The star is radiating 6.4[9] times the luminosity of the Sun from its photosphere at an effective temperature of 6,381 K.[7]
This star was identified as a member of the AB Doradus moving group by J. López-Santiago and collaborators in 2006.[16] It was later shown that its evolutionary state is incompatible with membership.[17]
In 2001, a faint co-moving companion was identified at an angular separation of 63.1″ from the primary.[18] This is equivalent to a linear projected separation of 2,456 AU (0.04 ly).[11] The companion, designated component B, is an L-class (~L0.5)[4] brown dwarf[18] with a mass of ~0.076 M☉.[11]
In April 2000, a planet was discovered using radial velocity measurements taken at Fred Lawrence Whipple Observatory and Lick Observatory.[14] The orbital parameters were updated in 2006 and 2007 using additional measurements.[19][20] A second planet with a much longer period was discovered in 2019.[21]
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | >8.35±0.18 MJ | 0.917±0.009 | 256.78±0.02 | 0.677±0.003 | — | — |
c (unconfirmed) | >5.36±4.57 MJ | 8.3±1.8 | 6,974±2,161 | 0.29±0.12 | — | — |