Astronomy:HD 179886
| Observation data Epoch J2000.0 Equinox (celestial coordinates) | |
|---|---|
| Constellation | Telescopium |
| Right ascension | 19h 16m 21.7422s[1] |
| Declination | −45° 27′ 57.704″[1] |
| Apparent magnitude (V) | 5.371[2] (5.59 + 8.63)[3] |
| Characteristics | |
| Evolutionary stage | red giant branch[1] |
| Spectral type | K3 III[4] |
| B−V color index | +1.35[5] |
| Astrometry | |
| Radial velocity (Rv) | 6.3±0.8[6] km/s |
| Proper motion (μ) | RA: −3.013[1] mas/yr Dec.: +10.017[1] mas/yr |
| Parallax (π) | 4.6441 ± 0.1537[1] mas |
| Distance | 700 ± 20 ly (215 ± 7 pc) |
| Absolute magnitude (MV) | −0.7[7] |
| Details | |
| Mass | 1.11[8] M☉ |
| Radius | 36.75[9] R☉ |
| Luminosity | 365[10] L☉ |
| Surface gravity (log g) | 1.3[8] cgs |
| Temperature | 4,622[10] K |
| Metallicity [Fe/H] | +0.15[8] dex |
| Rotational velocity (v sin i) | 2.4±1.1[11] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 179886 (HR 7289) is a binary star[3] located in the southern constellation Telescopium. It has a combined apparent magnitude of 5.37,[2] making it faintly visible to the naked eye if viewed under ideal conditions. The system is situated at a distance of 700 light years[1] but is receding with a heliocentric radial velocity of 6.3 km/s.[6]
As of 2018, the two stars have a separation of 0.4 arcseconds along a position angle of 205°[12]
The brighter component has a stellar classification of K3 III, indicating that the object is an ageing K-type giant. Models show it to be on the red giant branch,[1] a stage of stellar evolution where the star is fusing hydrogen in a shell around an inert core of helium. It has an angular diameter of 1.95±0.03,[13] yielding a diameter 37 times that of the Sun[9] at its estimated distance. At present it has 111% the mass of the Sun[8] and radiates at 365 solar luminosity[10] from its enlarged photosphere at an effective temperature of 4,622 K,[10] giving it an orange glow. HD 179886A has a metallicity 141% that of the Sun[8] and spins modestly with a projected rotational velocity of 2.4 km/s.[11]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode: 2021A&A...649A...1G. Gaia EDR3 record for this source at VizieR.
- ↑ 2.0 2.1 Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P. et al. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. ISSN 0004-6361. Bibcode: 2000A&A...355L..27H.
- ↑ 3.0 3.1 Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society 389 (2): 869–879. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode: 2008MNRAS.389..869E.
- ↑ Houk, Nancy (1978). Michigan catalogue of two-dimensional spectral types for the HD stars. Bibcode: 1978mcts.book.....H.
- ↑ Corben, P. M. (1971). "Photoelectric Magnitudes and Colours for Bright Southern Stars". Monthly Notes of the Astronomical Society of South Africa 30: 37. ISSN 0024-8266. Bibcode: 1971MNSSA..30...37C.
- ↑ 6.0 6.1 Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. ISSN 1063-7737. Bibcode: 2006AstL...32..759G.
- ↑ Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation" (in en). Astronomy Letters 38 (5): 331–346. doi:10.1134/S1063773712050015. ISSN 1063-7737. Bibcode: 2012AstL...38..331A.
- ↑ 8.0 8.1 8.2 8.3 8.4 Anders, F.; Khalatyan, A.; Chiappini, C.; Queiroz, A. B.; Santiago, B. X.; Jordi, C.; Girardi, L.; Brown, A. G. A. et al. (August 2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy & Astrophysics 628: A94. doi:10.1051/0004-6361/201935765. ISSN 0004-6361. Bibcode: 2019A&A...628A..94A.
- ↑ 9.0 9.1 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 10.0 10.1 10.2 10.3 McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (21 November 2012). "Fundamental parameters and infrared excesses of Hipparcos stars: Parameters and IR excesses from Hipparcos". Monthly Notices of the Royal Astronomical Society 427 (1): 343–357. doi:10.1111/j.1365-2966.2012.21873.x. ISSN 0035-8711. Bibcode: 2012MNRAS.427..343M.
- ↑ 11.0 11.1 De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (January 2014). "A catalog of rotational and radial velocities for evolved stars: V. Southern stars⋆⋆⋆". Astronomy & Astrophysics 561: A126. doi:10.1051/0004-6361/201220762. ISSN 0004-6361. Bibcode: 2014A&A...561A.126D.
- ↑ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal 122 (6): 3466–3471. doi:10.1086/323920. ISSN 0004-6256. Bibcode: 2001AJ....122.3466M.
- ↑ Richichi, A.; Percheron, I.; Khristoforova, M. (February 2005). "CHARM2: An updated Catalog of High Angular Resolution Measurements". Astronomy & Astrophysics 431 (2): 773–777. doi:10.1051/0004-6361:20042039. ISSN 0004-6361. Bibcode: 2005A&A...431..773R.
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