HD 215152
| Observation data Epoch J2000.0 Equinox J2000.0 |
|
|---|---|
| Constellation | Aquarius |
| Right ascension | 22h 43m 21.30188s[1] |
| Declination | −06° 24′ 02.96″[1] |
| Apparent magnitude (V) | 8.13[2] |
| Characteristics | |
| Spectral type | K3 V[3] |
| B−V color index | 0.968[4] |
| Astrometry | |
| Radial velocity (Rv) | −13.80[5] km/s |
| Proper motion (μ) | RA: −30.50[1] mas/yr Dec.: −6.10[1] mas/yr |
| Parallax (π) | 46.47 ± 0.90[1] mas |
| Distance | 70 ± 1 ly (21.5 ± 0.4 pc) |
| Details | |
| Mass | 0.756±0.016[6] M☉ |
| Surface gravity (log g) | 4.26±0.15[6] cgs |
| Temperature | 4,803±52[6] K |
| Metallicity [Fe/H] | −0.08±0.02[6] dex |
| Rotational velocity (v sin i) | 3.35[4] km/s |
| Age | 5.207±4.069[6] Gyr |
| Other designations | |
HD 215152 is the Henry Draper Catalogue designation for a star in the zodiac constellation of Aquarius. It has an apparent visual magnitude of 8.13,[2] meaning it is too faint to be seen with the naked eye. Parallax measurements made by the Hipparcos spacecraft provide a distance estimate of around 70 light years.[1] The star has a relatively high proper motion,[7] moving across the sky at an estimated 0.328 arc seconds per year along a position angle of 205°.[8]
This star has a stellar classification of K3 V,[3] which indicates that it is an ordinary K-type main sequence star. Based upon observation of regular variations in chromospheric activity, it has a rotation period of 36.5±1.6 days.[9] Stellar models give an estimated mass of around 76% of the Sun.[6] It has a slightly lower metallicity than the Sun,[6] and thus has a lower abundance of elements other than hydrogen and helium. The effective temperature of the stellar atmosphere is about 4,803 K, giving it the orange-hued glow of an ordinary K-type star.[10]
HD 215152 is a candidate for possessing a debris disk—a circumstellar disk of orbiting dust and debris. This finding was made through the detection of an infrared excess at a wavelength of 70 μm by the Spitzer Space Telescope. The detection has a 3σ level of certainty.[11]
In 2011, it was reported that two planetary candidates had been detected in close orbit around this star. The planets were discovered through Doppler spectroscopy using the HARPS spectrograph at La Silla Observatory in Chile. Their presence was revealed by periodic variations in the radial velocity of the host star due to gravitational perturbations by the orbiting objects. Both planets have brief orbital periods: the inner planet is orbiting the host star every 7.28 days while the outer planet orbits every 10.86 days. Their individual masses are more than twice that of the Earth, placing them in the regime of Super-Earth or Neptune mass planets.[12]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥ 2.78±0.47 M⊕ | 0.0652±0.0010 | 7.283±0.006 | 0.34±0.27 | — | — |
| c | ≥ 3.10±0.48 M⊕ | 0.0852±0.0014 | 10.866±0.014 | 0.38±0.23 | — | — |
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 2.0 2.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 4.0 4.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 7.0 7.1 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.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 12.0 12.1 Lua error in package.lua at line 80: module 'strict' not found.
