HD 200044

HD 200044 (HR 8044) is a solitary^[13] star in the equatorial constellation Delphinus. It has an apparent magnitude of 5.7,^[2] allowing it to be faintly seen with the naked eye. The object is located 598 light years away,^[1] but is approaching the Solar System with a heliocentric radial velocity of −15.07 km/s.^[7]

HD 200044

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Delphinus
Right ascension	21h 00m 27.6883s[1]
Declination	+19° 19′ 46.493″[1]
Apparent magnitude (V)	5.70±0.01[2]
Characteristics
Evolutionary stage	AGB[3]
Spectral type	M3 IIIab[4]
B−V color index	+1.61[5]
Variable type	suspected[6]
Astrometry
Radial velocity (Rv)	−15.07±0.09[7] km/s
Proper motion (μ)	RA: −15.483 mas/yr[1] Dec.: −59.705 mas/yr[1]
Parallax (π)	5.455 ± 0.0753 mas[1]
Distance	598 ± 8 ly (183 ± 3 pc)
Absolute magnitude (MV)	−0.33[8]
Details
Mass	1.32[9] M☉
Radius	58[10] R☉
Luminosity	507[11] L☉
Surface gravity (log g)	0.93[12] cgs
Temperature	3,707[10] K
Other designations
AG+19°2128, BD+18°4675, GC 29329, HD 200044, HIP 103675, HR 8044, SAO 106747, WDS J21005+1920A
Database references
SIMBAD	data

HD 200044 has a spectral classification of M3 IIIab,^[4] indicating that its an ageing red giant. It is currently on the asymptotic giant branch and is fusing hydrogen and helium in shells around an inert carbon core.^[3] As a consequence, it has expanded to 58 times the radius of the Sun and is now radiating with a luminosity over 500 times greater than that of the Sun. HD 200044's large size and high luminosity yield an effective temperature of 3,707 K, giving it a red glow. HD 200044 is suspected to be a variable star with an amplitude of 0.05 magnitudes.^[6]

There is a 10th magnitude optical companion separated 49.3″ away and at a position angle of 337° as of 2014. However, the separation is increasing due to HD 200044's high proper motion.^[14]

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. Eggen, Olin J. (July 1992). "Asymptotic giant branch stars near the sun". The Astronomical Journal. 104: 275. Bibcode:1992AJ....104..275E. doi:10.1086/116239. ISSN 0004-6256.
4. Yamashita, Y. (1967). "MK Spectral Types of Bright M-Type Stars". Publications of the Dominion Astrophysical Observatory Victoria. 13: 44. Bibcode:1967PDAO...13...47Y. ISSN 0078-6950.
5. Haggkvist, L.; Oja, T. (1970). "Results of BV photometry 1969-70 (Uppsala refractor)". Private Communication. Bibcode:1970Priv.........0H.
6. 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. eISSN 1562-6881. ISSN 1063-7729. S2CID 255195566.
7. Famaey, B.; Pourbaix, D.; Frankowski, A.; Van Eck, S.; Mayor, M.; Udry, S.; Jorissen, A. (18 February 2009). "Spectroscopic binaries among Hipparcos M giants". Astronomy & Astrophysics. 498 (2): 627–640. arXiv:0901.0934. Bibcode:2009A&A...498..627F. doi:10.1051/0004-6361/200810698. eISSN 1432-0746. ISSN 0004-6361.
8. 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.
9. Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (2022). "Stellar and substellar companions from Gaia EDR3. Proper-motion anomaly and resolved common proper-motion pairs". Astronomy and Astrophysics. 657: 657. arXiv:2109.10912. Bibcode:2022A&A...657A...7K. doi:10.1051/0004-6361/202142146. S2CID 237605138.
10. Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. ISSN 0004-6256.
11. 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.
12. McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017). "Fundamental parameters and infrared excesses of Tycho-Gaia stars". Monthly Notices of the Royal Astronomical Society. 471 (1): 770. arXiv:1706.02208. Bibcode:2017MNRAS.471..770M. doi:10.1093/mnras/stx1433.
13. Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
14. Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. ISSN 0004-6256.