Gliese 892 ( HR 8832 , HD 219134 , lat. Gliese 892 ) is a single star located in the constellation Cassiopeia at a distance of about 21 light-years from the Sun.
| Gliese 892 | |||
|---|---|---|---|
| Star | |||
| Observational data ( Age J2000) | |||
| Right ascension | |||
| Declination | |||
| Distance | 15.20 ± 0.01 St. years (4,660 ± 0,004 pc ) | ||
| Visible magnitude ( V ) | 5.56 | ||
| Constellation | Cassiopeia | ||
| Astrometry | |||
| Radial velocity ( R v ) | -18.83 [1] km / s | ||
| Own movement (μ) | RA: 2075.07 [1] Dec: 295.45 [1] | ||
| Parallax (π) | 152.76 ± 0.29 [1] mas | ||
| Absolute magnitude (V) | 6.57 | ||
| Specifications | |||
| Spectral class | K3V [1] | ||
| Color Index ( B - V ) | 0.99 | ||
| Color Index ( U - B ) | 0.89 | ||
| Variability | Flashing star | ||
| physical characteristics | |||
| Weight | 0.81 M ☉ | ||
| Radius | 0.80 ± 0.04 R ☉ | ||
| Temperature | 4380 K | ||
| Metallicity | 100% | ||
| |||
| Database Information | |||
| SIMBAD | data | ||
| Sources: [1] | |||
Content
Study History
For the first time, the star is mentioned under the name BD + 56 ° 2966 in the catalog of Friedrich Argelander , who had been observing it for 11 years. In the 19th century, Henry Draper defined the spectral class of a star and gave it the definition of HD 219134 in his catalog .
In 1999, studies were carried out for the presence of massive bodies orbiting a star [3] , but then large exoplanets or sub-dwarfs were not found in the Gliese 892 system.
In 2015, at the conference "Extremely accurate radial velocity measurements", held July 5-8 in the American city of New Haven (Connecticut), two groups of astronomers announced the discovery of 6 planets in the HD 219134 system (Gliese 892) [4] , four of which are confirmed as of July 2015. Among all confirmed exoplanets closer to the Sun, there is only a planet orbiting the red dwarf Gliese 674 (14.81 light years old) [5] , three planets at Gliese 876 (15.2 light years) and a planet at Gliese 832 (16, 1 St. year).
The inner planet HD 219134 b is a transit super-earth , its size is 1.6 times the diameter of the Earth [6] [7] . The planet was originally discovered using the HARPS - North tool on the Italian 3.6 meter Galileo telescope, which is installed in the Canary Islands [8] .
Features
Despite the fact that Gliese 892 is much dimmer than the Sun (only 21% of its luminosity ), it can be seen with the naked eye in clear weather. The star belongs to the class of orange dwarfs , in mass and diameter it is inferior to the Sun - 81% and 80% of the solar, respectively. Among other things, Gliese 892 is also a flashing star , that is, it spontaneously increases its brightness many times over, so in star catalogs it can be found under the name NSV 14458 .
Planet System
Below is a summary table of the characteristics of the planets of the Gliese 892 system:
| Planet | Weight ( M J ) | Radius ( R J ) | Circulation period ( days ) | Semimajor axis orbits ( a.u. ) | Eccentricity orbits |
|---|---|---|---|---|---|
| b | 0.12 | 0.1433 | 3.0931 | 0,038474 | 0 |
| c | 0.011 | - | 6.7635 | 0,064816 | 0 |
| d | 0,067 | - | 46.71 | 0.23508 | 0 |
| e | 0.0117 | - | 1842 | 2,56 | 0.34 |
| f | 0,028 | - | 22.8058 | 0.145743 | 0 |
| g | 0,034 | - | 94.2 | 0.3753 | 0 |
| h | 0.34 | - | 2247 | 3.11 | 0.06 |
Nearest star environment
The following star systems are within 10 light-years of Gliese 892:
| Star | Spectral class | Distance, st. years old |
| η Cassiopeia AB | G0 V / K7 V | 4.9 |
| EV Lizards | M3.5 Ve | 6.3 |
| BD + 61 2068 | M0 Ve | 7.2 |
| μ Cassiopeia AB | G5 VIp / M5 V | 7.3 |
| Kruger 60 AB | M3 V / M4 V | 8.4 |
| AC + 71 532 | M3.5 Ve | 9.3 |
| σ Dragon | K0 v | 9.5 |
| AC + 65 6955 | M3 v | 9.7 |
See also
- List of stars of the constellation Cassiopeia
Notes
- ↑ 1 2 3 4 5 6 SIMBAD (English) . - Gliese 892 in the SIMBAD database . Date of treatment January 23, 2016.
- ↑ 1 2 3 4 Gaia Data Release 2 - 2018.
- ↑ The Lick Planet Search: Detectability and Mass Thresholds
- ↑ Extreme Precision Radial Velocities // Yale University, New Haven Connecticut. 5 - 8 July 2015
- ↑ Astronomers have confirmed the existence of the nearest exoplanet-super-earth . N + 1 (July 31, 2015). Date of treatment July 31, 2015.
- ↑ Astronomers find star with three super-Earths (link not available) . Date of treatment July 30, 2015. Archived July 31, 2015.
- ↑ Astrophysicists have confirmed the discovery of exoplanets - the closest neighbor of the Earth
- ↑ Scientists have found a planet similar to Earth "in total" 21 light years from us (inaccessible link) . Date of treatment August 1, 2015. Archived March 4, 2016.