HD 215497

Last updated
HD 215497
Observation data
Epoch J2000.0       Equinox J2000.0
Constellation Tucana
Right ascension 22h 46m 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 constellation of Tucana. 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]

Planetary system

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]

The HD 215497 planetary system [2]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b ≥6.6  M🜨 0.0473.93404 ± 0.000660.16 ± 0.09
c ≥0.33  MJ 1.282567.94 ± 2.700.49 ± 0.04

References

  1. 1 2 3 4 5 6 Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics . 616. A1. arXiv: 1804.09365 . Bibcode: 2018A&A...616A...1G . doi: 10.1051/0004-6361/201833051 . Gaia DR2 record for this source at VizieR.
  2. 1 2 3 4 5 6 7 8 9 10 Lo Curto, G.; et al. (2015). "The HARPS search for southern extra-solar planets. XXII. Multiple planet systems from the HARPS volume limited sample". Astronomy and Astrophysics. 512. A48. arXiv: 1411.7048 . Bibcode: 2010A&A...512A..48L . doi: 10.1051/0004-6361/200913523 .
  3. 1 2 3 4 5 6 7 8 9 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv: 1108.4971 . Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID   119257644.
  4. 1 2 3 4 5 Bonfanti, A.; et al. (2016). "Age consistency between exoplanet hosts and field stars". Astronomy & Astrophysics. 585: 14. arXiv: 1511.01744 . Bibcode:2016A&A...585A...5B. doi:10.1051/0004-6361/201527297. S2CID   53971692. A5.
  5. "HD 215497". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-11-08.
  6. Mugrauer, M.; Ginski, C. (12 May 2015). "High-contrast imaging search for stellar and substellar companions of exoplanet host stars". Monthly Notices of the Royal Astronomical Society. 450 (3): 3127–3136. Bibcode:2015MNRAS.450.3127M. doi: 10.1093/mnras/stv771 . hdl: 1887/49340 . Retrieved 19 June 2020.
  7. Gillon, M.; et al. (May 2017). "The Spitzer search for the transits of HARPS low-mass planets. II. Null results for 19 planets". Astronomy & Astrophysics. 601: 23. arXiv: 1701.01303 . Bibcode:2017A&A...601A.117G. doi:10.1051/0004-6361/201629270. S2CID   86862862. A117.