HD 179070
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Lyra[1] |
| Right ascension | 19h 09m 26.8351s[2] |
| Declination | +38° 42′ 50.455″[2] |
| Apparent magnitude (V) | 8.25[3] |
| Characteristics | |
| Spectral type | F6IV[4] |
| Apparent magnitude (J) | 7.229±0.032[5] |
| Apparent magnitude (H) | 7.031±0.023[5] |
| Apparent magnitude (K) | 6.945±0.018[5] |
| Variable type | Planetary transit variable[4] |
| Astrometry | |
| Proper motion (μ) | RA: 27.951±0.054[2] mas/yr Dec.: 28.585±0.056[2] mas/yr |
| Parallax (π) | 9.1859 ± 0.0323[2] mas |
| Distance | 355 ± 1 ly (108.9 ± 0.4 pc) |
| Details[6] | |
| Mass | 1.408+0.021 −0.030 M☉ |
| Radius | 1.902+0.018 −0.012 R☉ |
| Luminosity | 5.188+0.142 −0.128 L☉ |
| Surface gravity (log g) | 4.026±0.004 cgs |
| Temperature | 6305±50 K |
| Metallicity [Fe/H] | −0.03±0.10 dex |
| Rotation | 12.62±0.03 d[3] |
| Rotational velocity (v sin i) | 8.4±0.5[3] km/s |
| Age | 2.60±0.16 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 179070 also known as Kepler 21 is a F-type subgiant star. A transiting exoplanet was discovered orbiting this star by the Kepler spacecraft.[4] At a magnitude of 8.25 this was the brightest star observed by Kepler to host a validated planet until the discovery of an exoplanet orbiting HD 212657 in 2018.[3][8]
Planetary system
The single known planet orbiting this star was identified as a candidate based on photometry from the first four months of data from the Kepler spacecraft.[9] Confirmation was obtained in 2012 after extensive follow-up observations and analysis of the Kepler light curves.[4]
The calculated density of the planet is approximately 6.4 g cm−3, similar to earth's 5.5 g cm−3, which suggests a rocky composition. With an equilibrium temperature of 2025 Kelvin, the top few-hundred kilometers of the planet is probably molten.[3]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| Kepler-21b | 5.08±1.72 M⊕ | 0.0427172±0.0000003 | 2.7858212±0.0000032 | 0.02±0.1 | 83.20+0.28 −0.26° |
1.639+0.019 −0.015 R⊕ |
References
- ↑ Lua error in package.lua at line 80: module 'strict' not found. Vizier query form
- ↑ 2.0 2.1 2.2 2.3 2.4 Template:Cite DR2
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 4.0 4.1 4.2 4.3 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 5.0 5.1 5.2 Lua error in package.lua at line 80: module 'strict' not found.Vizier catalog entry
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
