HD 204521

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HD 204521
Cepheus IAU.svg
Red circle.svg
Location of HD 204521; not visible on this chart, but just to the west of β Cephei (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Cepheus
Right ascension 21h 25m 16.79707s[1]
Declination +70° 28′ 39.1412″[1]
Apparent magnitude (V) 7.26[2] (binoculars)
Characteristics
Spectral type G0V[3]
B−V color index 0.619±0.015[2]
Astrometry
Radial velocity (Rv)−76.6±0.3[2] km/s
Proper motion (μ) RA: +40.601[1] mas/yr
Dec.: +39.564[1] mas/yr
Parallax (π)37.9131 ± 0.0279[1] mas
Distance86.03 ± 0.06 ly
(26.38 ± 0.02 pc)
Absolute magnitude (MV)5.15[2]
Details
Mass0.77±0.03[4] or 0.997[5] M☉
Luminosity0.86[2] L☉
Surface gravity (log g)4.43±0.02[4] cgs
Temperature5,699±50[4] K
Metallicity [Fe/H]−0.75±0.05[4] dex
Age8.43±4.24[6] Gyr
Other designations
BD+69°1169, GJ 4194, HD 204521, HIP 105766, SAO 10045, TYC 4465-1133-1[7]
Database references
SIMBADdata

HD 204521 is a star in the northern constellation of Cepheus. In the sky it positioned just to the west of the magnitude 3.2 star Beta Cephei (β Cep). This object has a yellow hue similar to the Sun but is too faint to be visible to the naked eye with an apparent visual magnitude of 7.26.[2] It is located at a distance of 86 light years from the Sun based on parallax, and has an absolute magnitude of 5.15.[2] The star is drifting closer with a radial velocity of −77 km/s,[2] and is predicted to come to within 7.96 light-years in 334,000 years.[5] At that distance the star can have a relatively small perturbing effect on comets in the Oort cloud.[8]

This is an ordinary G-type main-sequence star with a stellar classification of G0V,[3] indicating that it is generating energy through core hydrogen fusion. It is roughly 8[6] billion years old and appears metal-deficient.[9] The mass of this star appears to be at or below that of the Sun, and it is radiating 86%[2] of the Sun's luminosity from its photosphere at an effective temperature of 5,699 K.[4]

References[]

  1. ^ a b c d e 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.
  2. ^ a b c d e f g h i Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
  3. ^ a b 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. arXiv:astro-ph/0308182. Bibcode:2003AJ....126.2048G. doi:10.1086/378365. S2CID 119417105.
  4. ^ a b c d e Aguilera-Gómez, Claudia; et al. (2018). "Lithium abundance patterns of late-F stars: An in-depth analysis of the lithium desert". Astronomy and Astrophysics. 614: A55. arXiv:1803.05922. Bibcode:2018A&A...614A..55A. doi:10.1051/0004-6361/201732209. S2CID 62799777.
  5. ^ a b Bailer-Jones, C.A.L.; et al. (2018). "New stellar encounters discovered in the second Gaia data release". Astronomy & Astrophysics. 616: A37. arXiv:1805.07581. Bibcode:2018A&A...616A..37B. doi:10.1051/0004-6361/201833456. S2CID 56269929.
  6. ^ a b Pace, G. (March 2013). "Chromospheric activity as age indicator. An L-shaped chromospheric-activity versus age diagram". Astronomy & Astrophysics. 551: 4. arXiv:1301.5651. Bibcode:2013A&A...551L...8P. doi:10.1051/0004-6361/201220364. S2CID 56420519. L8.
  7. ^ "HD 204521". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-03-07.
  8. ^ Torres, S.; et al. (September 2019). "Galactic tide and local stellar perturbations on the Oort cloud: creation of interstellar comets". Astronomy & Astrophysics. 629: 13. arXiv:1906.10617. Bibcode:2019A&A...629A.139T. doi:10.1051/0004-6361/201935330. S2CID 195584070. A139.
  9. ^ Bond, Howard E. (September 1970). "A Search for Metal-Deficient Stars". Astrophysical Journal Supplement. 22: 117. Bibcode:1970ApJS...22..117B. doi:10.1086/190220.

External links[]

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