Astronomy:HD 204521
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 21h 25m 16.79696s[1] |
| Declination | +70° 28′ 39.1434″[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) | −76.78±0.12[1] km/s |
| Proper motion (μ) | RA: +40.632[1] mas/yr Dec.: +39.411[1] mas/yr |
| Parallax (π) | 37.9375 ± 0.0155[1] mas |
| Distance | 85.97 ± 0.04 ly (26.36 ± 0.01 pc) |
| Absolute magnitude (MV) | 5.15[2] |
| Details | |
| Mass | 0.77±0.03[4] or 0.997[5] M☉ |
| Radius | 0.92[1] R☉ |
| Luminosity | 0.76[1] L☉ |
| Surface gravity (log g) | 4.43±0.02[4] cgs |
| Temperature | 5,699±50[4] K |
| Metallicity [Fe/H] | −0.75±0.05[4] dex |
| Rotational velocity (v sin i) | 3.6[6] km/s |
| Age | 8.43±4.24[7] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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.[9]
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 billion years old[7] and appears metal-deficient.[10] The mass of this star appears to be at or below that of the Sun, and it is radiating 76% of the Sun's luminosity from its photosphere at an effective temperature of 5,699 K.[4]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 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.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 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. doi:10.1086/378365. Bibcode: 2003AJ....126.2048G.
- ↑ 4.0 4.1 4.2 4.3 4.4 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. doi:10.1051/0004-6361/201732209. Bibcode: 2018A&A...614A..55A.
- ↑ 5.0 5.1 Bailer-Jones, C.A.L. et al. (2018). "New stellar encounters discovered in the second Gaia data release". Astronomy & Astrophysics 616: A37. doi:10.1051/0004-6361/201833456. Bibcode: 2018A&A...616A..37B.
- ↑ Glebocki, R.; Gnacinski, P. (2005). "VizieR Online Data Catalog: Catalog of Stellar Rotational Velocities (Glebocki+ 2005)". VizieR On-line Data Catalog: III/244. Originally Published in: 2005csss...13..571G; 2005yCat.3244....0G 3244. Bibcode: 2005yCat.3244....0G.
- ↑ 7.0 7.1 Pace, G. (March 2013). "Chromospheric activity as age indicator. An L-shaped chromospheric-activity versus age diagram". Astronomy & Astrophysics 551: 4. doi:10.1051/0004-6361/201220364. L8. Bibcode: 2013A&A...551L...8P.
- ↑ "HD 204521". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+204521.
- ↑ Torres, S. et al. (September 2019). "Galactic tide and local stellar perturbations on the Oort cloud: creation of interstellar comets". Astronomy & Astrophysics 629: 13. doi:10.1051/0004-6361/201935330. A139. Bibcode: 2019A&A...629A.139T.
- ↑ Bond, Howard E. (September 1970). "A Search for Metal-Deficient Stars". Astrophysical Journal Supplement 22: 117. doi:10.1086/190220. Bibcode: 1970ApJS...22..117B.
External links
- Wikisky image of HD 204521 (HIP 105766)
- List of G stars within 100 light-years
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