Gliese 412
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ursa Major |
| Gliese 412 A | |
| Right ascension | 11h 05m 22.3101s |
| Declination | +43° 31′ 51.0404″ |
| Apparent magnitude (V) | 8.68 |
| Gliese 412 B | |
| Right ascension | 11h 05m 30.8856s |
| Declination | +43° 31′ 17.8843″ |
| Apparent magnitude (V) | 14.45 |
| Characteristics | |
| Spectral type | M1.0V/M6.0V |
| U−B color index | +1.16/— |
| B−V color index | +1.54/2.08 |
| Astrometry | |
| Gliese 412 A | |
| Radial velocity (Rv) | +64.9 ± 0.9 km/s |
| Proper motion (μ) | RA: −4410.43±0.78 mas/yr Dec.: 942.93±0.70 mas/yr |
| Parallax (π) | 203.8876±0.0332 mas |
| Distance | 15.997 ± 0.003 ly (4.9047 ± 0.0008 pc) |
| Absolute magnitude (MV) | 10.34 |
| Gliese 412 B | |
| Proper motion (μ) | RA: −4339.891±0.167 mas/yr Dec.: 960.780±0.162 mas/yr |
| Parallax (π) | 203.8323 ± 0.0500 mas |
| Distance | 16.001 ± 0.004 ly (4.906 ± 0.001 pc) |
| Absolute magnitude (MV) | 16.05 |
| Details | |
| GJ 412 A | |
| Mass | 0.48 M☉ |
| Radius | 0.398±0.009 R☉ |
| Surface gravity (log g) | 4.90 cgs |
| Temperature | 3,687/ K |
| Metallicity [Fe/H] | -0.43 dex |
| Rotational velocity (v sin i) | <3 km/s |
| Age | 3 Gyr |
| GJ 412 B | |
| Mass | 0.10 M☉ |
| Radius | 0.13 R☉ |
| Temperature | 2,700 K |
| Metallicity [Fe/H] | −0.32 dex |
| Rotational velocity (v sin i) | 7.7±1.7 km/s |
| Other designations | |
| BD+44°2051, GJ 412, CCDM J11055+4332AB, WDS J11055+4332AB
A: Gaia DR2 778947814402405120, HIP 54211, SAO 43609, G 176-11, LAL 21258, LFT 757, LHS 38, LTT 12976, NLTT 26245 B: WX UMa, Gaia DR2 778947608243864320, G 176-12, LFT 758, LHS 39, LTT 12977, NLTT 26247 | |
| Database references | |
| SIMBAD | The system |
| A | |
| B | |
Location of Gliese 412 in the constellation Ursa Major | |
Gliese 412 is a pair of stars that share a common proper motion through space and are thought to form a binary star system. The pair have an angular separation of 31.4″ at a position angle of 126.1°. They are located 15.8 light-years distant from the Sun in the constellation Ursa Major. Both components are relatively dim red dwarf stars.
This system, also known as Lalande 21258, was announced in 1860 as a high apparent proper motion star by Friedrich Wilhelm Argelander as a result of work on the Bonner Durchmusterung (BD). Adalbert Krueger, an assistant to the BD project, was tasked with measuring its parallax. In Krueger's paper reporting the result, he dubbed it Argelander's Third Star.
The two stellar components of this system have a projected separation of about 152 AU, and an estimated orbital semimajor axis of 190 AU. The primary has about 48% of the Sun's mass, while the secondary is only 10%. The primary has a projected rotation velocity at the equator of less than 3 km/s; the secondary has a rotation velocity of 7.7±1.7 km/s.
The primary star was monitored for radial velocity (RV) variations caused by a Jupiter-mass companion in a short-period orbit. It displayed no significant excess of RV variation that could be attributed to a planet. A search of the system using near-infrared speckle interferometry also failed to detect a companion orbiting at distances of 1–10 AU. Nor has a brown dwarf been detected orbiting within this system.
The space velocity components of this system are U = 141, V = –7 and W = 7. They are members of the halo population of the Milky Way galaxy.