HD 176693
HD 176693, also known as Kepler-408, is a star with a close orbiting exoplanet in the northern constellation of Draco. It is located at a distance of 291 light years from the Sun based on parallax measurements, but it is drifting closer with a radial velocity of −55 km/s. The star is predicted to come as close as 23.1 light-years in 1.6 million years. It has an apparent visual magnitude of 8.83, which is too faint to be viewed with the naked eye.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Draco |
| Right ascension | 18h 59m 08.684s |
| Declination | 48° 25′ 23.60″ |
| Apparent magnitude (V) | 8.83 |
| Characteristics | |
| Evolutionary stage | Main sequence |
| Spectral type | F8V |
| B−V color index | 0.51 |
| Astrometry | |
| Radial velocity (Rv) | −54.76±0.18 km/s |
| Proper motion (μ) | RA: 4.704±0.013 mas/yr Dec.: 9.263±0.016 mas/yr |
| Parallax (π) | 11.2176 ± 0.0126 mas |
| Distance | 290.8 ± 0.3 ly (89.1 ± 0.1 pc) |
| Details | |
| Mass | 1.05±0.04 M☉ |
| Radius | 1.253±0.051 R☉ |
| Luminosity | 1.864 L☉ |
| Surface gravity (log g) | 4.318+0.08 −0.089 cgs |
| Temperature | 6,080±65 K |
| Metallicity [Fe/H] | −0.138+0.043 −0.042 dex |
| Rotation | 12.89±0.19 d |
| Rotational velocity (v sin i) | 2.8±1.0 km/s |
| Age | 7.15±1.61 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The spectrum of HD 176693 matches an F-type main-sequence star with a stellar classification of F8V. The star is older than the Sun, at 7.15 billion years. It is slightly and uniformly depleted in heavy elements compared to the Sun, having about 75% of the solar abundance of iron and other heavy elements. HD 176693 is a chromospherically inactive star, although there is weak evidence for tidal spin-up due to star-planet interaction.
HD 176693 is 5% more massive than the Sun and has a 25% larger radius. It is radiating 1.9 times the luminosity of the Sun from its photosphere at an effective temperature of 6,080 K. The star is spinning with a rotation period of 12.89 days. As of 2016, multiplicity surveys have not detect any stellar companions to HD 176693.