22h46m36.7543s, −56° 35′ 58.322″| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Tucana |
| Right ascension | 22h46m 36.75396s[1] |
| Declination | −56° 35′ 58.3285″[1] |
| Apparent magnitude (V) | 8.96[2] |
| Characteristics | |
| Spectral type | K3V[2] |
| Apparent magnitude (B) | 9.913[3] |
| Apparent magnitude (J) | 7.339±0.024[3] |
| Apparent magnitude (H) | 6.917±0.053[3] |
| Apparent magnitude (K) | 6.784±0.024[3] |
| B−V color index | 0.953±0.025[3] |
| Astrometry | |
| Radial velocity (Rv) | +49.31[3] km/s |
| Proper motion (μ) | RA: −54.660±0.041[1] mas/yr Dec.: −61.028±0.045[1] mas/yr |
| Parallax (π) | 24.6339 ± 0.0324 mas[1] |
| Distance | 132.4 ± 0.2 ly (40.59 ± 0.05 pc) |
| Absolute magnitude (MV) | 5.77[3] |
| Details[4] | |
| Mass | 0.86±0.02 M☉ |
| Radius | 0.87±0.02 R☉ |
| Luminosity | 0.47±0.02 L☉ |
| Surface gravity (log g) | 4.49±0.03 cgs |
| Temperature | 5,128±12 K |
| Metallicity [Fe/H] | 0.23±0.07[2] dex |
| Rotational velocity (v sin i) | 1.67[2] km/s |
| Age | 9.9±2.8 Gyr |
| Other designations | |
CPD−57°10139, HD 215497, HIP 112441, SAO 247578, PPM 350516, TYC 8826-00247-1, 2MASS J22463675-5635584[5] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
HD 215497 is a single[4] star in the southern constellationofTucana. It has an orange hue with an apparent visual magnitude of 8.96,[2] which is too dim to be viewed with the naked eye. A 2015 survey ruled out the existence of any stellar companions at projected distances from 26 to 300 astronomical units.[6] Based on parallax measurements,[1] it is located at a distance of 132 light years from the Sun. The star is drifting further away with a radial velocity of +49 km/s, having come as close as 45 light-years some 774,000 years ago.[3] The absolute magnitude of this star is 5.77.[3]
The stellar classification of HD 215497 is K3V,[2] indicating this is a K-type main-sequence star that is generating energy through core hydrogen fusion. The star is about ten[4] billion years old with a low magnetic activity level and is spinning with a projected rotational velocity of 1.67 km/s.[2] It is smaller than the Sun, with 86% of the Sun's mass and 87% of the radius.[4] This is a metal-rich star, which means the abundance of heavier elements in the atmosphere is significantly higher than in the Sun.[2] It is radiating 47% of the luminosity of the Sun from its photosphere at an effective temperature of 5,128 K.[4]
Announced in 2009, two extrasolar planets were discovered to be orbiting the star.[2] Both planets are less massive than Jupiter. The inner exoplanet HD 215497 b orbits very close to the star and is termed a "hot super-Earth". The outer exoplanet HD 215497 c is a giant planet that orbits a little bit further from the star than the Earth, at around 1.282 AU, with a high eccentricity. A check for transits of the inner planet did not reveal any passages.[7]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥6.6 M🜨 | 0.047 | 3.93404 ± 0.00066 | 0.16 ± 0.09 | — | — |
| c | ≥0.33 MJ | 1.282 | 567.94 ± 2.70 | 0.49 ± 0.04 | — | — |
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