HD 15115
F-type subgiant star in the constellation Cetus
HD 15115 is a single[ 10] star in the equatorial constellation of Cetus . It is readily visible in binoculars or a small telescope, but is considered too dim to be seen with the naked eye at an apparent visual magnitude of 6.76.[ 2] The distance to this object is 160 light years based on parallax ,[ 1] and it is slowly drifting further away at the rate of about 1 km/s.[ 5] It has been proposed as a member of the Beta Pictoris moving group [ 11] or the Tucana-Horologium association of co-moving stars; there is some ambiguity as to its true membership.[ 12]
This object has a stellar classification of F4IV,[ 3] suggesting it is an aging subgiant star that has exhausted the supply of hydrogen at its core . MacGregor and associates (2015) instead classify it as a young F-type main-sequence star with a class of F2V.[ 4] Age estimates give a value of 500[ 8] million years, while membership in the β Pictoris moving group would indicate an age of around 21± 4 million .[ 4] It has 1.19[ 6] times the mass of the Sun , 1.39[ 1] times the Sun's radius , and has a relatively high rate of spin with a projected rotational velocity of 90 km/s.[ 7] The star is radiating 3.74[ 1] times the luminosity of the Sun from its photosphere at an effective temperature of 6,811 K.[ 1] Its metallicity – the abundance of elements other than hydrogen and helium – is nearly the same as in the Sun.[ 6]
HD 15115 was shown to have an asymmetric debris disk surrounding it, which is being viewed nearly edge-on. The reason for the asymmetry is thought to be either the gravitational pull of a passing star (HIP 12545), an exoplanet , or interaction with the local interstellar medium .[ 13] A magnitude 11.35 visual companion lies at an angular separation of 12.6″ along a position angle of 195°, as of 2015.[ 11]
References
^ a b c d e f g h i j k l 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 .
^ a b c d Oja, T. (1983). "UBV photometry of FK4 and FK4 supplement stars". Astronomy and Astrophysics Supplement Series . 52 : 131. Bibcode :1983A&AS...52..131O .
^ a b Harlan, E. A. (1974). "MK classification for F- and G-type stars. III". Astronomical Journal . 79 : 682. Bibcode :1974AJ.....79..682H . doi :10.1086/111597 .
^ a b c MacGregor, Meredith A.; et al. (March 2015). "Resolved Millimeter Emission from the HD 15115 Debris Disk". The Astrophysical Journal . 801 (1): 8. arXiv :1501.05962 . Bibcode :2015ApJ...801...59M . doi :10.1088/0004-637X/801/1/59 . S2CID 118407532 . 59.
^ a b Desidera, S.; et al. (January 2015). "The VLT/NaCo large program to probe the occurrence of exoplanets and brown dwarfs in wide orbits. I. Sample definition and characterization". Astronomy & Astrophysics . 573 : 45. arXiv :1405.1559 . Bibcode :2015A&A...573A.126D . doi :10.1051/0004-6361/201323168 . S2CID 55486025 . A126.
^ a b c d e Luck, R. Earle (March 2018), "Abundances in the Local Region. III. Southern F, G, and K Dwarfs", The Astronomical Journal , 155 (3): 31, Bibcode :2018AJ....155..111L , doi :10.3847/1538-3881/aaa9b5 , S2CID 125765376 , 111.
^ a b Pribulla, Theodor; et al. (September 2014). "Cerro Armazones spectroscopic survey of F dwarfs" . Monthly Notices of the Royal Astronomical Society . 443 (3): 2815–2823. Bibcode :2014MNRAS.443.2815P . doi :10.1093/mnras/stu1333 .
^ a b Decin, G.; et al. (November 2003), "Age Dependence of the Vega Phenomenon: Observations", The Astrophysical Journal , 598 (1): 636–644, arXiv :astro-ph/0308294 , Bibcode :2003ApJ...598..636D , doi :10.1086/378800 , S2CID 16751327
^ "HD 15115" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-11-15 .
^ Rodriguez, David R.; Zuckerman, B. (February 2012). "Binaries among Debris Disk Stars". The Astrophysical Journal . 745 (2): 13. arXiv :1111.5618 . Bibcode :2012ApJ...745..147R . doi :10.1088/0004-637X/745/2/147 . S2CID 73681879 . 147.
^ a b Alonso-Floriano, F. J.; et al. (November 2015). "Reaching the boundary between stellar kinematic groups and very wide binaries. III. Sixteen new stars and eight new wide systems in the β Pictoris moving group". Astronomy & Astrophysics . 583 : 24. arXiv :1508.06929 . Bibcode :2015A&A...583A..85A . doi :10.1051/0004-6361/201526795 . S2CID 3131908 . A85.
^ Malo, Lison; et al. (January 2013), "Bayesian Analysis to Identify New Star Candidates in Nearby Young Stellar Kinematic Groups", The Astrophysical Journal , 762 (2): 50, arXiv :1209.2077 , Bibcode :2013ApJ...762...88M , doi :10.1088/0004-637X/762/2/88 , S2CID 118497872 , 88.
^ Debes, J. H.; et al. (2009). "Interstellar Medium Sculpting of the Hd 32297 Debris Disk". The Astrophysical Journal . 702 (1): 318–326. arXiv :0908.4368 . Bibcode :2009ApJ...702..318D . doi :10.1088/0004-637X/702/1/318 . S2CID 15303091 .