HD 177830
Coordinates: 19h 05m 20.7735s, +25° 55′ 14.379″
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Lyra |
Right ascension | 19h 05m 20.7732s[1] |
Declination | +25° 55′ 14.373″[1] |
Apparent magnitude (V) | 7.175 |
Characteristics | |
Spectral type | K0IV[2]/M4V[3] |
Details | |
Gyr | |
Other designations | |
Database references | |
SIMBAD | data |
HD 177830 is a 7th
light years, it is not visible to the unaided eye. With binoculars
it should be easily visible.
The primary star is known to have two
extrasolar planets
orbiting around it.
Stellar system
The secondary star is a Red dwarf star orbiting at a distance of 100 to 200 AU with a likely period of roughly 800 years.[3]
Planetary system
On November 1, 1999,brown dwarf desert") making the claim even more unlikely.
On November 17, 2010, the discovery of a second planet HD 177830 c was announced along with four other planets. The planet has 50% the mass of Saturn and takes 111 days to orbit the star in a very eccentric orbit. This planet is in a near 4:1 resonance with the outer planet.[6]
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
c | ≥0.15 ± 0.03 MJ | 0.5137 ± 0.0006 | 110.9 ± 0.3 | 0.3495 ± 0.0002 | — | — |
b | ≥1.49 ± 0.03 MJ | 1.2218 ± 0.0008 | 406.6 ± 0.4 | 0.009 ± 0.004 | — | — |
See also
- List of exoplanets discovered before 2000 - HD 177830 b
- List of exoplanets discovered in 2010 - HD 177830 c
References
- ^ S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ doi:10.1086/308981.
- ^ .
- S2CID 53666931.
- ^ doi:10.1086/428383.
- ^ .
- ^ "HD 177830 -- Double or multiple star". SIMBAD Astronomical Database. Centre de données astronomiques de Strasbourg. Retrieved 2014-10-11.
- ^ "Astronomers discover six new planets orbiting nearby stars" (Press release). Kamuela, Hawaii: W. M. Keck Observatory. November 1, 1999. Retrieved December 19, 2017.