23 Ursae Majoris, or 23 UMa, is a binary star system in the constellation Ursa Major,[4] located is approximately 77.7 light years from the Sun.[1] It has the Bayer designation h Ursae Majoris; 23 Ursae Majoris is the Flamsteed designation. The system is visible to the naked eye as a yellow-white hued star with an apparent visual magnitude of +3.65.[2] It is moving closer to the Earth with a heliocentric radial velocity of −10 km/s.[2]

23 Ursae Majoris
Location of 23 Ursae Majoris (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Ursa Major
Right ascension 09h 31m 31.70873s[1]
Declination +63° 03′ 42.7013″[1]
Apparent magnitude (V) +3.65[2] / +9.0
Characteristics
Spectral type F0IV[3]
B−V color index 0.360±0.015[2]
Astrometry
Radial velocity (Rv)−10.4±0.7[2] km/s
Proper motion (μ) RA: +107.99[1] mas/yr
Dec.: + 27.15[1] mas/yr
Parallax (π)41.99 ± 0.16 mas[1]
Distance77.7 ± 0.3 ly
(23.82 ± 0.09 pc)
Details
23 UMa A
Mass1.862[3] M
Radius2.90±0.03[3] R
Luminosity14.8±0.1[3] L
Temperature6,651±27[3] K
Metallicity [Fe/H]0.17[3] dex
Age1.3[3] Gyr
Other designations
h UMa, 23 UMa, BD+63°845, FK5 355, GJ 3534, HD 81937, HIP 46733, HR 3757, SAO 14908, CCDM J09315+6303A/B[4]
Database references
SIMBADdata

The primary component is a yellow-white F-type subgiant with an apparent magnitude of +3.65. It has 1.9 times the Sun's mass, 2.9 times the Sun's radius and is emitting 15 times the luminosity of the Sun[5] at an effective temperature of 6,651 K.[3] Orbiting at an angular separation of 22.7 arcseconds is the 9th magnitude secondary companion. There is a magnitude +10.5 optical companion at an angular separation of 99.6 arcseconds.

Nomenclature

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With τ, υ, φ, θ, e and f, it composed the Arabic asterism Sarīr Banāt al-Na'sh, the Throne of the daughters of Na'sh, and Al-Haud, the Pond.[6] According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, Al-Haud was the title for seven stars : f as Alhaud I, τ as Alhaud II, e as Alhaud III, this star (h) as Alhaud IV, θ as Alhaud V, υ as Alhaud VI and φ as Alhaud VII .[7]

References

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  1. ^ a b c d e f Van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
  2. ^ a b c d e 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 c d e f g h Boyajian, Tabetha S.; et al. (July 2013), "Stellar Diameters and Temperatures. III. Main-sequence A, F, G, and K Stars: Additional High-precision Measurements and Empirical Relations", The Astrophysical Journal, 771 (1): 31, arXiv:1306.2974, Bibcode:2013ApJ...771...40B, doi:10.1088/0004-637X/771/1/40, S2CID 14911430, 40. See Table 3.
  4. ^ a b "h UMa". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-03-19.
  5. ^ Boyajian, Tabetha S.; et al. (February 2012), "Stellar Diameters and Temperatures. I. Main-sequence A, F, and G Stars", The Astrophysical Journal, 746 (1): 101, arXiv:1112.3316, Bibcode:2012ApJ...746..101B, doi:10.1088/0004-637X/746/1/101, S2CID 18993744. See Table 10.
  6. ^ Allen, Richard Hinckley (1899), Star-Names and Their Meanings, New York: G. E. Stechert, p. 442.
  7. ^ Rhoads, Jack W. (November 15, 1971), Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars (PDF), Jet Propulsion Laboratory, California Institute of Technology.
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