10 Delphini

10 Delphini (10 Del) is a solitary star in the equatorial constellation Delphinus. It has an apparent magnitude of 6.00, allowing it to be faintly seen with the naked eye. Parallax measurements put the object at a distance of 493 light years but is drifting closer with a heliocentric radial velocity of −32 km/s.

10 Delphini

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Delphinus
Right ascension	20h 41m 16.2079s[1]
Declination	+14° 34′ 58.3606″[1]
Apparent magnitude (V)	6.00±0.01[2]
Characteristics
Spectral type	K4 III[3]
U−B color index	+1.44[4]
B−V color index	+1.24[5]
Astrometry
Radial velocity (Rv)	−32±2[6] km/s
Proper motion (μ)	RA: −9.462 mas/yr[1] Dec.: −0.344 mas/yr[1]
Parallax (π)	6.6178 ± 0.0397 mas[1]
Distance	493 ± 3 ly (151.1 ± 0.9 pc)
Absolute magnitude (MV)	+0.06[7]
Details
Mass	2.42±0.71[8] M☉
Radius	18.47+1.02 −1.03[9] R☉
Luminosity	125±2[9] L☉
Surface gravity (log g)	2.27[10] cgs
Temperature	4,378[10] K
Metallicity [Fe/H]	0.00[10] dex
Age	794±33[8] Myr
Other designations
10 Del, AG+14°2269, BD+14°4393, GC 28826, HD 197121, HIP 102080, HR 7918, SAO 106384
Database references
SIMBAD	data

10 Delphini has a stellar classification of K4 III^[3] or K2 III,^[11] both indicating that it is a red giant. However, there is some uncertainty behind the first classification. It has twice the mass of the Sun^[8] but at an age of 794 million years^[8] — expanded to 18 times the radius of the Sun.^[9] It shines at 125 L_☉^[9] from its enlarged photosphere at an effective temperature of 4,378 K,^[10] giving it an orange glow. 10 Del has a solar metallicity.^[10]

10 Del has been suspected to be a variable star, although it hasn't been catalogued as such in the GCVS.^[12]

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
2. Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361.
3. Adams, Walter S.; Joy, Alfred H.; Humason, Milton L.; Brayton, Ada Margaret (April 1935). "The Spectroscopic Absolute Magnitudes and Parallaxes of 4179 Stars". The Astrophysical Journal. 81: 187. Bibcode:1935ApJ....81..187A. doi:10.1086/143628. ISSN 0004-637X.
4. Paunzen, E. (May 2022). "Catalogue of stars measured in the Geneva seven-colour photometric system". Astronomy & Astrophysics. 661: A89. arXiv:2111.04810. Bibcode:2022A&A...661A..89P. doi:10.1051/0004-6361/202142355. eISSN 1432-0746. ISSN 0004-6361.
5. Haggkvist, L.; Oja, T. (1970). "Results of BV photometry 1969-70 (Uppsala refractor)". Private Communication. Bibcode:1970Priv.........0H.
6. Famaey, B.; Jorissen, A.; Luri, X.; Mayor, M.; Udry, S.; Dejonghe, H.; Turon, C. (2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters". Astronomy and Astrophysics. 430: 165. arXiv:astro-ph/0409579. Bibcode:2005A&A...430..165F. doi:10.1051/0004-6361:20041272. S2CID 17804304.
7. Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. ISSN 1063-7737. S2CID 255204555.
8. Feuillet, Diane K.; Bovy, Jo; Holtzman, Jon; Girardi, Léo; MacDonald, Nick; Majewski, Steven R.; Nidever, David L. (20 January 2016). "Determining Ages of Apogee Giants with Known Distances". The Astrophysical Journal. 817 (1): 40. arXiv:1511.04088. Bibcode:2016ApJ...817...40F. doi:10.3847/0004-637X/817/1/40. eISSN 1538-4357.
9. 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.
10. Forsberg, R.; Jönsson, H.; Ryde, N.; Matteucci, F. (November 2019). "Abundances of disk and bulge giants from high-resolution optical spectra". Astronomy & Astrophysics. 631: A113. arXiv:1909.10535. Bibcode:2019A&A...631A.113F. doi:10.1051/0004-6361/201936343. eISSN 1432-0746. ISSN 0004-6361.
11. Bartkevicius, A.; Lazauskaite, R. (1 January 1997). "Classification of Population II Stars in the Vilnius Photometric System. II. Results". Open Astronomy. 6 (4): 499. Bibcode:1997BaltA...6..499B. doi:10.1515/astro-1997-0402. eISSN 2543-6376.
12. Samus’, N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (January 2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. ISSN 1063-7729. S2CID 255195566.