Astronomy:HD 208741

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Short description: Star in the constellation Octans
HD 208741
Observation data
{{#ifeq:J2000|J2000.0 (ICRS)|Epoch J2000.0      Equinox J2000.0 (ICRS)| Epoch J2000      [[Astronomy:Equinox (celestial coordinates)|Equinox J2000}}
Constellation Octans
A
Right ascension  22h 03m 03.8227s[1]
Declination −76° 07′ 06.453″[1]
Apparent magnitude (V) 5.93±0.01[2]
B
Right ascension  22h 03m 12.9150s[3]
Declination −76° 06′ 54.860″[3]
Apparent magnitude (V) 10.57[4]
Characteristics
A
Evolutionary stage main sequence[5]
Spectral type F3 III[6][7]
U−B color index +0.11[8]
B−V color index +0.39[8]
B
Spectral type K5[9]
B−V color index +0.7
Astrometry
Radial velocity (Rv)8±1.1[10] km/s
Absolute magnitude (MV)+1.96[11]
A
Proper motion (μ) RA: +24.821[1] mas/yr
Dec.: −72.437[1] mas/yr
Parallax (π)15.4736 ± 0.0383[1] mas
Distance210.8 ± 0.5 ly
(64.6 ± 0.2 pc)
B
Proper motion (μ) RA: +29.912[3] mas/yr
Dec.: −71.414[3] mas/yr
Parallax (π)15.5058 ± 0.0249[3] mas
Distance210.3 ± 0.3 ly
(64.5 ± 0.1 pc)
Details
A
Mass1.52±0.25[12] M
Radius2.6±0.1[12] R
Luminosity12.9[13] L
Surface gravity (log g)3.89[14] cgs
Temperature6,937±80[14] K
Metallicity [Fe/H]+0.33[14] dex
Rotational velocity (v sin i)36[15] km/s
Age1.1±0.1[16] Gyr
Other designations
Database references
SIMBADA
B

HD 208741, also known as HR 8380, is a yellowish-white hued star located in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.91,[2] making it faintly visible to the naked eye. Parallax measurements place it at a distance of 211 light years,[1] and it is currently receding with a heliocentric radial velocity of km/s.[10]

HD 208741 has a 10th magnitude K-type main-sequence companion[9] separated by 34.8.[4] Together, they make up a wide binary system designated collectively as CPD−76°1542.[4] Sir John Herschel, the discoverer of the pair, noted the primary to be a probable spectroscopic binary.[17]

This object has a stellar classification of F3 III,[6][7] indicating that it is a slightly evolved F-type star. Gaia Data Release 3 models it to be a dwarf that is 81.3% through its main sequence lifetime.[5] At present it has 1.52 times the mass of the Sun and a slightly enlarged radius of 2.6 R[12] due to its evolved state. It radiates at 12.9 times the luminosity of the Sun[13] from its photosphere at an effective temperature of 6,937 K.[14] HD 208741 has a metallicity twice the Sun's,[14] making it metal enriched. It is estimated to be 1.1 billion years old,[16] and is spinning with a projected rotational velocity of 36 km/s.[15]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 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. Bibcode2021A&A...649A...1G.  Gaia EDR3 record for this source at VizieR.
  2. 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. Bibcode2000A&A...355L..27H. 
  3. 3.0 3.1 3.2 3.3 3.4 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. Bibcode2021A&A...649A...1G.  Gaia EDR3 record for this source at VizieR.
  4. 4.0 4.1 4.2 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. Bibcode2001AJ....122.3466M. 
  5. 5.0 5.1 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  6. 6.0 6.1 de Vaucouleurs, A. (1 August 1957). "Spectral Types and Luminosities of B, A and F Southern Stars". Monthly Notices of the Royal Astronomical Society 117 (4): 449–462. doi:10.1093/mnras/117.4.449. ISSN 0035-8711. Bibcode1957MNRAS.117..449D. 
  7. 7.0 7.1 Malaroda, S. (August 1975). "Study of the F-type 1 MK spectral types.". The Astronomical Journal 80: 637. doi:10.1086/111786. ISSN 0004-6256. Bibcode1975AJ.....80..637M. 
  8. 8.0 8.1 Johnson, H. L.; Mitchell, R. I.; Iriarte, B.; Wisniewski, W. Z. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory 4: 99–110. Bibcode1966CoLPL...4...99J. 
  9. 9.0 9.1 Stoy, R. H. (1966). "Cape photographic catalogue for 1950.0; Meridian positions of standard stars, zone −64° to −80°". Annals of the Cape Observatory 21: 0. Bibcode1966AnCap..21....0S. 
  10. 10.0 10.1 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. Bibcode2006AstL...32..759G. 
  11. Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331–346. doi:10.1134/S1063773712050015. ISSN 1063-7737. Bibcode2012AstL...38..331A. 
  12. 12.0 12.1 12.2 Stassun, Keivan G. et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. Bibcode2019AJ....158..138S. 
  13. 13.0 13.1 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. Bibcode2012MNRAS.427..343M. 
  14. 14.0 14.1 14.2 14.3 14.4 Casagrande, L.; Schönrich, R.; Asplund, M.; Cassisi, S.; Ramírez, I.; Meléndez, J.; Bensby, T.; Feltzing, S. (26 May 2011). "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s): Improved astrophysical parameters for the Geneva-Copenhagen Survey⋆". Astronomy & Astrophysics 530: A138. doi:10.1051/0004-6361/201016276. ISSN 0004-6361. Bibcode2011A&A...530A.138C. 
  15. 15.0 15.1 Erspamer, D.; North, P. (28 January 2003). "Automated spectroscopic abundances of A and F-type stars using echelle spectrographs". Astronomy & Astrophysics 398 (3): 1121–1135. doi:10.1051/0004-6361:20021711. ISSN 0004-6361. Bibcode2003A&A...398.1121E. 
  16. 16.0 16.1 Nordström, B.; Mayor, M.; Andersen, J.; Holmberg, J.; Pont, F.; Jørgensen, B. R.; Olsen, E. H.; Udry, S. et al. (16 April 2004). "The Geneva-Copenhagen survey of the Solar neighbourhood". Astronomy & Astrophysics 418 (3): 989–1019. doi:10.1051/0004-6361:20035959. ISSN 0004-6361. Bibcode2004A&A...418..989N. 
  17. Herschel, J. F. W. (1835). "A Second Series of Micrometrical Measures of Double Stars chiefly performed with the 7-feet Equatorial, at Slough, in the years 1831, 1832, and 1833". Memoirs of the Royal Astronomical Society 8: 37. Bibcode1835MmRAS...8...37H.