Jump to content

HD 186756

Edit links
From Wikipedia, the free encyclopedia
HD 186756
Location of HD 186756 (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Telescopium
Right ascension 19h 48m 55.08814s[1]
Declination −52° 53′ 17.1953″[1]
Apparent magnitude (V) 6.25[2]
Characteristics
Spectral type K1 III[3]
U−B color index +1.12[2]
B−V color index +1.13[2]
Astrometry
Radial velocity (Rv)−21.2±0.4[4] km/s
Proper motion (μ) RA: +14.802 mas/yr[1]
Dec.: −48.522 mas/yr[1]
Parallax (π)4.3872 ± 0.0275 mas[1]
Distance743 ± 5 ly
(228 ± 1 pc)
Absolute magnitude (MV)−0.96[5]
Details
Mass1.23[6] M☉
Radius21.01±1.07[7] R☉
Luminosity177±2[8] L☉
Surface gravity (log g)1.83[6] cgs
Temperature4,747±122[9] K
Metallicity [Fe/H]−0.13[6] dex
Rotational velocity (v sin i)<1[10] km/s
Other designations
68 G. Telescopii[11], CD−53°8294, CPD−53°9678, FK5 3581, GC 27384, HD 186756, HIP 97491, HR 7521, SAO 246277[12]
Database references
SIMBADdata

HD 186756, also known as HR 7521 or rarely 68 G. Telescopii, is a solitary orange hued star located in the southern constellation Telescopium. It has an apparent magnitude of 6.25,[2] placing it near the limit for naked eye visibility, even under ideal conditions. Gaia DR3 parallax measurements imply a distance of 743 light years;[1] it is currently approaching with a heliocentric radial velocity of −21.2 km/s.[4] At its current distance, HD 186756's brightness is diminished by 0.34 magnitudes due to extinction from interstellar dust[13] and it has an absolute magnitude of −0.96.[5]

This is an evolved red giant star with a stellar classification of K1 III. It has 123% the mass of the Sun[6] but it has expanded to 21.01 times the radius of the Sun.[7] The object radiates 177 times the luminosity of the Sun[8] from its enlarged photosphere at an effective temperature of 4,747 K.[9] HD 186756 is slightly metal deficient with an iron abundance of [Fe/H] = −0.13 (74% solar) and it spins too slowly for its projected rotational velocity to be measured accurately.[10]

References

[edit]
  1. ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  2. ^ a b c d Oja, T. (1970). "UBV-Fotometri danska Tel (ESO)". Private Communication: 0. Bibcode:1970Priv.........0O.
  3. ^ Houk, Nancy (1978). Michigan catalogue of two-dimensional spectral types for the HD stars: Declinations −53° to −40°. Vol. 2. Bibcode:1978mcts.book.....H.
  4. ^ a b 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. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. eISSN 1562-6873. ISSN 1063-7737. S2CID 119231169.
  5. ^ a b Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. eISSN 1562-6873. ISSN 1063-7737. S2CID 119257644.
  6. ^ a b c d Anders, F.; et al. (August 2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy & Astrophysics. 628: A94. arXiv:1904.11302. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765. eISSN 1432-0746. ISSN 0004-6361. S2CID 131780028.
  7. ^ a b Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (October 2004). "The angular sizes of dwarf stars and subgiants. Surface brightness relations calibrated by interferometry". Astronomy & Astrophysics. 426 (1): 297–307. arXiv:astro-ph/0404180. Bibcode:2004A&A...426..297K. doi:10.1051/0004-6361:20035930. eISSN 1432-0746. ISSN 0004-6361. S2CID 6077801.
  8. ^ a b 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.
  9. ^ a b Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. eISSN 1538-3881. hdl:1721.1/124721. S2CID 166227927.
  10. ^ a b 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. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. eISSN 1432-0746. ISSN 0004-6361. S2CID 54046583.
  11. ^ Gould, Benjamin Apthorp (1878). "Uranometria Argentina : brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : con atlas". Resultados del Observatorio Nacional Argentino. 1. Bibcode:1879RNAO....1.....G.
  12. ^ "HD 186756". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved April 20, 2023.
  13. ^ Gontcharov, George A.; Mosenkov, Aleksandr V. (28 September 2017). "Verifying reddening and extinction for Gaia DR1 TGAS main sequence stars". Monthly Notices of the Royal Astronomical Society. 472 (4): 3805–3820. arXiv:1709.01160. Bibcode:2017MNRAS.472.3805G. doi:10.1093/mnras/stx2219. eISSN 1365-2966. ISSN 0035-8711. S2CID 118879856.
Retrieved from "https://en.wikipedia.org/w/index.php?title=HD_186756&oldid=1154746632"