Astronomy:HD 197027

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Short description: Star in the constellation Capricornus
HD 197027
HIP 102152.jpg
HIP 102152
Credit: ESO/Digitized Sky Survey 2
Observation data
Epoch J2000.0   Equinox (celestial coordinates)
Constellation Capricornus
Right ascension  20h 41m 54.6336s[1]
Declination −27° 12′ 57.4154″[1]
Apparent magnitude (V) 9.15±0.02[2]
Characteristics
Spectral type G3 V[3]
U−B color index +0.30[4]
B−V color index +0.65[2]
Astrometry
Radial velocity (Rv)−43.9±0.3[5] km/s
Proper motion (μ) RA: +175.628[1] mas/yr
Dec.: −15.593[1] mas/yr
Parallax (π)12.7715 ± 0.0164[1] mas
Distance255.4 ± 0.3 ly
(78.3 ± 0.1 pc)
Absolute magnitude (MV)4.74[6]
Details
Mass0.97[7] M
Radius1.08+0.07−0.05[8] R
Luminosity1.19[6] L
Surface gravity (log g)4.40±0.02[9] cgs
Temperature5718±5[9] K
Metallicity [Fe/H]−0.020±0.005[9] dex
Rotational velocity (v sin i)1.78±0.12[9] km/s
Age6.92±0.69[9] Gyr
Other designations
CD−27°14976, CPD−27°7079, HD 197027, HIP 102152, SAO 189585[10]
Database references
SIMBADdata

HD 197027 (HIP 102152) is a star in the constellation Capricornus. It has an apparent magnitude of 9.15,[2] making it readily visible through a telescope but not to the naked eye. The object is located at a distance of 255 light years but is approaching the Solar System with a heliocentric radial velocity of −44 km/s.[5]

HD 197027 has a stellar classification of G3 V, indicating that it is an ordinary G-type main-sequence star like the Sun. It has only 97% the mass of the Sun[7] but 108% of its radius.[8] It shines at 119% the luminosity of the Sun[6] from its photosphere at an effective temperature of 5,718 K,[9] similar to the Sun's 5,778 K. HD 197027's metallicity – elements heavier than helium – is similar to the Sun.[9] At an older age of 6.92 billion years, it spins with a projected rotational velocity of about km/s.[9]

Since its measured properties of this star are very similar to those of the Sun, it has been considered a candidate older solar twin.[11] The abundances of 21 elements overall are more similar to the Sun than any other known solar twin. [citation needed] Its Iron Abundance is -0.03 with an error value of 0.02 Fe/H. (The value comes from the Hipparcos Extended Catalog.)[12]

Age

The age of HD 197027, here annotated as HIP 102152, shown relative to the Sun, the younger solar twin 18 Scorpii and the formation of the Milky Way

References

  1. 1.0 1.1 1.2 1.3 1.4 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.
  2. 2.0 2.1 2.2 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. Houk, N. (1982). Michigan Catalogue of Two-dimensional Spectral Types for the HD stars. Volume_3. Declinations -40_ƒ0 to -26_ƒ0.. Bibcode1982mcts.book.....H. 
  4. Paunzen, E. (May 2022). "Catalogue of stars measured in the Geneva seven-colour photometric system". Astronomy & Astrophysics 661: A89. doi:10.1051/0004-6361/202142355. ISSN 0004-6361. Bibcode2022A&A...661A..89P. 
  5. 5.0 5.1 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. 
  6. 6.0 6.1 6.2 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. Bibcode2012AstL...38..331A. 
  7. 7.0 7.1 Talawanda R. Monroe (Aug 2013). "High Precision Abundances of the Old Solar Twin HIP 102152: Insights on Li Depletion from the Oldest Sun". Astrophysical Journal Letters 774 (2): L32. doi:10.1088/2041-8205/774/2/l32. Bibcode2013ApJ...774L..32M. 
  8. 8.0 8.1 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. ISSN 0004-6256. Bibcode2019AJ....158..138S. 
  9. 9.0 9.1 9.2 9.3 9.4 9.5 9.6 9.7 dos Santos, Leonardo A. et al. (August 2016), "The Solar Twin Planet Search. IV. The Sun as a typical rotator and evidence for a new rotational braking law for Sun-like stars", Astronomy & Astrophysics 592: 8, doi:10.1051/0004-6361/201628558, A156, Bibcode2016A&A...592A.156D. 
  10. "HD 197027". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+197027. 
  11. ESO, The life cycle of a Sun-like star (annotated), from European Southern Observatory, 28 August 2013
  12. "HD 197027 Star Distance, Age, Colour and other Facts - Universe Guide" (in en-us). 10 January 2024. https://www.universeguide.com/star/102152/hd197027. 

External links