HD 181720 - star , which is in the constellation Sagittarius at a distance of about 190 light years from us. At least one planet is drawn around the star.
| HD 181720 | |||
|---|---|---|---|
| Star | |||
 Author's idea of an exoplanet orbiting its star | |||
| Observational data ( Epoch J2000.0 ) | |||
| Right ascension | |||
| Declination | |||
| Distance | 190 ± 10 over . years (56 ± 4 pc ) [1] | ||
| Visible magnitude ( V ) | 7.84 [1] | ||
| Constellation | Sagittarius | ||
| Astrometry | |||
| Radial velocity ( R v ) | -57.2 [2] km / s | ||
| Proper motion (μ) | RA: 89.37 [2] mas per year Dec: -415.98 [2] mas per year | ||
| Parallax (π) | 17.88 ± 1.31 [2] mas | ||
| Absolute magnitude (V) | 4.10 [1] | ||
| Specifications | |||
| Spectral class | G1V [2] | ||
| Color Indicator ( B - V ) | 0.599 [1] | ||
| physical characteristics | |||
| Weight | 0.92 [1] M ☉ | ||
| Radius | 1.39 [1] R ☉ | ||
| Temperature | 5781 ± 18 [1] K | ||
| Luminosity | 1.94 [1] L ☉ | ||
| Metallicity | -0.53 ± 0.02 [1] | ||
| Rotation | 1.5 km / s [1] | ||
| |||
| Information in databases | |||
| SIMBAD | data | ||
| Sources: [2] | |||
Characteristics
HD 181720 belongs to the class of yellow dwarfs and its characteristics resemble our Sun. Its diameter and mass are 1.39 and 0.92 solar, respectively. The star is almost 2 times brighter than the Sun; its surface temperature is 5781 degrees Kelvin , but its chromospheric activity is extremely low. [one]
Planetary system
In 2009, a team of astronomers announced the discovery [1] of the planet HD 181720 b . The discovery was made under the HARPS program, along with 29 other planets. The gas giant HD 181720 b has a minimum mass equal to 0.37 mass of Jupiter and turns at an average distance of 1.78 a. e. from the parent star along an elongated elliptical orbit. A year on this planet lasts approximately 956 days.
| Planet | Weight ( M J ) | Radius ( R j ) | Period of treatment ( days ) | Big axis orbits ( a. e ) | Eccentricity orbits |
|---|---|---|---|---|---|
| b | ≥0.37 | ? | 956 ± 14 | 1.78 | 0.26 ± 0.06 |
Notes
- ↑ 1 2 3 4 5 6 7 8 9 10 11 12 NC Santos, M. Mayor, W. Benz, F. Bouchy, P. Figueira, G. Lo Curto, C. Lovis, C. Melo, C. Moutou, D Naef, F. Pepe, D. Queloz, SG Sousa, S. Udry. The HARPS search for southern extrasolar planets XXI. Three new giant planets orbiting the metal-poor stars HD5388, HD181720, and HD190984 (eng.) . Arxiv.org (Dec 16, 2009). The appeal date is January 14, 2010.
- ↑ 1 2 3 4 5 6 SIMBAD (English) . - HD 181720 in the SIMBAD database . The appeal date is January 15, 2010.
See also
- List of stars in the constellation Sagittarius