Gliese 412 is a binary star system in the constellation Ursa Major. Among the nearest stars, they lie at a distance of 16.0 light-years (4.9 parsecs). The pair have an angular separation of 31.4″ at a position angle of 126.1°. Both components are relatively dim red dwarf stars.
Gliese 412 Location of Gliese 412 in the constellation Ursa Major | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ursa Major |
| Gliese 412 A | |
| Right ascension | 11h 05m 28.57695s |
| Declination | +43° 31′ 36.3869″ |
| Apparent magnitude (V) | 8.68 |
| Gliese 412 B | |
| Right ascension | 11h 05m 30.88558s |
| Declination | +43° 31′ 17.8852″ |
| Apparent magnitude (V) | 14.45 |
| Characteristics | |
| Gliese 412 A | |
| Spectral type | M1.0V |
| U−B color index | +1.16 |
| B−V color index | +1.54 |
| Gliese 412 B | |
| Spectral type | M6.0V |
| B−V color index | +2.08 |
| Astrometry | |
| Gliese 412 A | |
| Radial velocity (Rv) | +68.41±0.12 km/s |
| Proper motion (μ) | RA: −4,406.469 mas/yr Dec.: +938.527 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 | |
| Radial velocity (Rv) | +67.94±0.74 km/s |
| Proper motion (μ) | RA: −4,339.850 mas/yr Dec.: +960.696 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 | |
| Gliese 412 A | |
| Mass | 0.387±0.010 M☉ |
| Radius | 0.398±0.009 R☉ |
| Luminosity | 0.0223±0.0004 L☉ |
| Surface gravity (log g) | 4.860±0.031 cgs |
| Temperature | 3,639±51 K |
| Metallicity [Fe/H] | −0.30±0.16 dex |
| Rotation | 36.9±2.5 d |
| Rotational velocity (v sin i) | <3 km/s |
| Age | 3 Gyr |
| Gliese 412 B | |
| Mass | 0.0952±0.0095 M☉ |
| Radius | 0.1262±0.0054 R☉ |
| Luminosity | 0.000915±0.000024 L☉ |
| Temperature | 2,863±60 K |
| Metallicity [Fe/H] | −0.32±0.08 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 | A |
| B | |
History of observations
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 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.
Characteristics
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 0.387 times the mass of the Sun, 0.398 times the Sun's radius and 2.23% of the Sun's luminosity. It is spinning at a rotation velocity at the equator of less than 3 km/s. The secondary is smaller and fainter, at 9.52% of the Sun's mass, 12.62% of the Sun's radius and luminosity only 0.09% solar. It is spinning at a rotation velocity of 7.7±1.7 km/s. Gliese 412 A has a temperature of 3,639 K, while Gliese 412 B has 2,863 K.
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.
X-ray source
The secondary is a flare star that is referred to as WX Ursae Majoris. It is characterized as a UV Ceti-type variable star that displays infrequent increases in luminosity. This star was observed to flare as early as 1939 by the Dutch astronomer Adriaan van Maanen.
Component B (WX Ursae Majoris) has been identified as an X-ray source, while no significant X-ray emission was detected from component A. This system had not been studied in X-rays prior to ROSAT.
See also
- List of nearest stars
- X-ray astronomy
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