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HD 204521

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	21 25 16.79696
Declination	+70° 28′ 39.1434″
Apparent magnitude (V)	7.26 (binoculars)
Characteristics
Spectral type	G0V
B−V color index	0.619±0.015
Astrometry
Radial velocity (Rv)	−76.78±0.12 km/s
Proper motion (μ)	RA: +40.632 mas/yr Dec.: +39.411 mas/yr
Parallax (π)	37.9375 ± 0.0155 mas
Distance	85.97 ± 0.04 ly (26.36 ± 0.01 pc)
Absolute magnitude (MV)	5.15
Details
Mass	0.77±0.03 or 0.997 M☉
Radius	0.92 R☉
Luminosity	0.76 L☉
Surface gravity (log g)	4.43±0.02 cgs
Temperature	5,699±50 K
Metallicity	−0.75±0.05 dex
Rotational velocity (v sin i)	3.6 km/s
Age	8.43±4.24 Gyr
Other designations
BD+69°1169, GJ 4194, HD 204521, HIP 105766, SAO 10045, TYC 4465-1133-1
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. It is located at a distance of 86 light years from the Sun based on parallax, and has an absolute magnitude of 5.15. The star is drifting closer with a radial velocity of −77 km/s, and is predicted to come to within 7.96 light-years in 334,000 years. At that distance the star can have a relatively small perturbing effect on comets in the Oort cloud.

This is an ordinary G-type main-sequence star with a stellar classification of G0V, indicating that it is generating energy through core hydrogen fusion. It is roughly 8 billion years old and appears metal-deficient. 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.

References

1. ^ 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. ^ 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. ^ 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. ^ 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. ^ 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. 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. ^ 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.
8. "HD 204521". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-03-07.
9. 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.
10. 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

• Wikisky image of HD 204521 (HIP 105766)
• List of G stars within 100 light-years

v t e Constellation of Cepheus
List of stars in Cepheus Cepheus in Chinese astronomy
Stars	Bayer α (Alderamin) β (Alfirk) γ (Errai) δ ε ζ η θ ι κ λ μ (Garnet Star) ν ξ (Kurhah) ο π ρ ρ Flamsteed 7 9 11 14 16 19 24 2 UMi Variable AR T V W RW VV VW WZ DH DO MY PV S SS ST U V354 V381 V419 HR 597 881 7955 8281 8442 8702 8748 8938 9038 HD 1 197911 204521 Other Gliese 809 WISE 0313+7807 WR 156 IRAS 23077+6707
Exoplanets γ Cephei Ab (Tadmor) TOI-1431 b
Star clusters	NGC 188 6939 7023 7129 7142 7160 7380 7419 7429 7510 Other Palomar 1
Nebulae	NGC NGC 40 NGC 7129 NGC 7139 NGC 7354 NGC 7538 NGC 7822 Other Seahorse Nebula Elephant's Trunk Nebula Ghost Nebula Gyulbudaghian's Nebula IC 1396 Iris Nebula L1157 S 155 SSTGFLS J222557+601148
Galaxies	NGC 2276 2300 6952 Other 3C 61.1 S5 0014+81 NVSS 2146+82 UGC 11861
Category

• G-type main-sequence stars
• Cepheus (constellation)
• Durchmusterung objects
• Gliese and GJ objects
• Henry Draper Catalogue objects
• Hipparcos objects