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HD 215497 is a single star in the southern constellation of Tucana. It has an orange hue with an apparent visual magnitude of 8.96, 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. Based on parallax measurements, 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. The absolute magnitude of this star is 5.77.

The stellar classification of HD 215497 is K3V, indicating this is a K-type main-sequence star that is generating energy through core hydrogen fusion. The star is about ten billion years old with a low magnetic activity level and is spinning with a projected rotational velocity of 1.67 km/s. It is smaller than the Sun, with 86% of the Sun's mass and 87% of the radius. This is a metal-rich star, which means the abundance of heavier elements in the atmosphere is significantly higher than in the Sun. It is radiating 47% of the luminosity of the Sun from its photosphere at an effective temperature of 5,128 K.

Planetary system

Announced in 2009, two extrasolar planets were discovered to be orbiting the star. 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.

References

1. ^ 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. ^ 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. ^ 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. ^ 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.

v t e Constellation of Tucana
List of stars in Tucana Tucana in Chinese astronomy
Stars	Bayer α β β β γ δ ε ζ η θ ι κ λ λ μ ν π ρ Variable DS HR 8829 HD 4308 5980 7199 (Emiw) 215497 221287 (Poerava) Other AB7 Gliese 54 HV 2112 HV 11417 HV 11423 L 168-9 PMMR 62 SMC 018136
Exoplanets DS Tucanae Ab HD 4308 b HD 7199 b (Hairu) HD 215497 b c HD 219077 b HD 221287 b (Pipitea)
Star clusters	NGC 121 152 176 220 222 231 241 256 265 267 269 290 294 299 306 330 339 346 361 362 371 376 395 411 416 419 422 456 458 460 465 Other ξ (47)
Nebulae E0102
Galaxies	NGC 53 360 406 432 434 440 466 484 7329 Other ESO 148-2 ISOHDFS 27 Tucana Dwarf Small Magellanic Cloud (partly in Hydrus)
Category

• K-type main-sequence stars
• Planetary systems with two confirmed planets
• Tucana
• Durchmusterung objects
• Henry Draper Catalogue objects
• Hipparcos objects