HD 195564
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Capricornus |
| Right ascension | 20h 32m 23.69559s[1] |
| Declination | −09° 51′ 12.1731″[1] |
| Apparent magnitude (V) | 5.65[2] |
| Characteristics | |
| Spectral type | G2 V[3] |
| U−B color index | +0.20[2] |
| B−V color index | +0.68[2] |
| Astrometry | |
| Radial velocity (Rv) | +9.58[4] km/s |
| Proper motion (μ) | RA: +307.35[1] mas/yr Dec.: +106.94[1] mas/yr |
| Parallax (π) | 40.98 ± 0.33[1] mas |
| Distance | 79.6 ± 0.6 ly (24.4 ± 0.2 pc) |
| Details | |
| HD 195564 A | |
| Mass | 1.097[5] M☉ |
| Radius | 1.867±0.083[5] R☉ |
| Luminosity | 2.705±0.047[5] L☉ |
| Surface gravity (log g) | 3.74[3] cgs |
| Temperature | 5421±118[5] K |
| Metallicity [Fe/H] | +0.06[5] dex |
| Rotational velocity (v sin i) | 1.91[6] km/s |
| Age | 8.2[5] Gyr |
| HD 195564 B | |
| Mass | 0.55[7] M☉ |
| Other designations | |
HD 195564 is the Henry Draper Catalogue designation for a star in the southern constellation of Capricornus. It is faintly visible to the naked eye with an apparent visual magnitude of 5.65.[2] Parallax measurements from the Hipparcos spacecraft give us an estimate of its distance as around 80 light years. This appears to be a wide binary system as a faint companion star shares a common proper motion with the brighter primary component.[7]
Based upon the spectrum of light emitted by the primary, it has a stellar classification of G2 V.[3] This indicates that it is a G-type main sequence star that is generating energy through the process of thermonuclear fusion in its core region. It has an estimated mass of 1.097[5] times the mass of the Sun, but a measured radius that is 1.867 times as large.[5] As a result, it shines with 2.705 times the luminosity of the Sun.[5] The abundance of elements in this star is similar to that in the Sun, although it is an older star with an age of around 8.2 billion years.[5] The effective temperature of the stellar atmosphere is 5,421 K,[5] giving it the yellow-hued glow of an ordinary K-type star.[9]
The secondary companion has an apparent magnitude of 11.30,[10] and a mass just 55% that of the Sun.[7] As measured in 1965, it had an angular separation of 3.20″ from the primary, along a position angle of 27°[10] The pair orbit each other with an estimated period of around 510 years.[7]
References
- 1 2 3 4 5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752
, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. - 1 2 3 4 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV data, SIMBAD, Bibcode:1986EgUBV........0M.
- 1 2 3 Gray, R. O.; et al. (2003), "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 Parsecs: The Northern Sample. I", The Astronomical Journal, 126 (4): 2048–2059, arXiv:astro-ph/0308182, Bibcode:2003AJ....126.2048G, doi:10.1086/378365.
- ↑ Nidever, David L.; et al. (August 2002), "Radial Velocities for 889 Late-Type Stars", The Astrophysical Journal Supplement Series, 141 (2): 503−522, arXiv:astro-ph/0112477, Bibcode:2002ApJS..141..503N, doi:10.1086/340570.
- 1 2 3 4 5 6 7 8 9 10 11 Boyajian, Tabetha S.; et al. (July 2013), "Stellar Diameters and Temperatures. III. Main-sequence A, F, G, and K Stars: Additional High-precision Measurements and Empirical Relations", The Astrophysical Journal, 771 (1): 31, arXiv:1306.2974, Bibcode:2013ApJ...771...40B, doi:10.1088/0004-637X/771/1/40, 40. See Table 3.
- ↑ Martínez-Arnáiz, R.; et al. (September 2010), "Chromospheric activity and rotation of FGK stars in the solar vicinity. An estimation of the radial velocity jitter", Astronomy and Astrophysics, 520: A79, arXiv:1002.4391, Bibcode:2010A&A...520A..79M, doi:10.1051/0004-6361/200913725.
- 1 2 3 4 Tokovinin, Andrei (April 2014), "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs", The Astronomical Journal, 147 (4): 14, arXiv:1401.6827, Bibcode:2014AJ....147...87T, doi:10.1088/0004-6256/147/4/87, 87.
- ↑ "HD 195564 -- Double or multiple star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved March 15, 2016
- ↑ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, retrieved 2012-01-16.
- 1 2 Mason, B. D.; et al. (2014), The Washington Visual Double Star Catalog, Bibcode:2001AJ....122.3466M, doi:10.1086/323920, retrieved 2015-07-22.