15 Ursae Majoris

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15 Ursae Majoris
Observation data
Epoch J2000.0       Equinox J2000.0
Constellation Ursa Major
Right ascension 09h 08m 52.25763s [1]
Declination +51° 36′ 16.7330″ [1]
Apparent magnitude  (V)4.46 [2]
Characteristics
Spectral type kA3VmF5IIISr [3]
B−V color index 0.288±0.013 [2]
Astrometry
Radial velocity (Rv)−0.1±0.7 [4]  km/s
Proper motion (μ)RA: −136.33 [1]   mas/yr
Dec.: −32.60 [1]   mas/yr
Parallax (π)34.70 ± 0.24  mas [1]
Distance 94.0 ± 0.7  ly
(28.8 ± 0.2  pc)
Absolute magnitude  (MV)2.16 [2]
Details
Mass 1.86 [5]   M☉
Radius 1.3 [6]   R☉
Luminosity 11.31 [2]   L☉
Surface gravity (log g)3.77±0.08 [7]   cgs
Temperature 7,519±98 [7]   K
Metallicity [Fe/H]0.55±0.05 [7]   dex
Rotational velocity (v sin i)42 [8]  km/s
Age 220 [5]   Myr
Other designations
f UMa, 15 UMa, BD+52°1365, FK5  2721, GJ  3534, HD  78209, HIP  44901, HR  3619, SAO  27136 [9]
Database references
SIMBAD data

15 Ursae Majoris is a star in the northern circumpolar constellation Ursa Major, located 94  light-years away from the Sun. [1] It has the Bayer designation f Ursae Majoris; 15 Ursae Majoris is the Flamsteed designation. It is visible to the naked eye as a white-hued star with an apparent visual magnitude of 4.46. [2] 15 Ursae Majoris is a suspected member of the Castor stellar kinematic group, a 200-million-year-old association of co-moving stars. [10]

According to Eggleton and Tokovinin (2008), this is a suspected binary star system with an orbital period of 4.9 days and an eccentricity of 0.2. [11] However, De Rosa et al. (2014) did not find a companion. [5] The primary is metallic-lined (Am) star, meaning it has unusually strong absorption lines of metals in its spectrum. Classification of the spectrum is difficult due to the peculiarities. An MK classification of 15 UMa using the calcium K line is A3 V, but using metallic spectral lines it can appear as a cooler and more luminous star. Spectral lines in the blue region give a classification of F5 Ib, while in the violet region the lines suggest F5 III/IV. [3]

Nomenclature

With τ, h, υ Ursae Majoris, φ, θ and e it composed the Arabic asterism Sarīr Banāt al-Na'sh, the Throne of the daughters of Na'sh, and Al-Haud, the Pond. [12] According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, Al-Haud were the title for seven stars: this star (f) as Alhaud I, τ as Alhaud II, e as Alhaud III, h as Alhaud IV, θ as Alhaud V, υ as Alhaud VI and φ as Alhaud VII. [13]

In Chinese, 文昌 (Wén Chāng), meaning Administrative Center , refers to an asterism consisting six stars, such as 15 Ursae Majoris, υ Ursae Majoris, θ Ursae Majoris and φ Ursae Majoris. [14] [15]

Related Research Articles

<span class="mw-page-title-main">Epsilon Ursae Majoris</span> Star in the constellation Ursa Major

Epsilon Ursae Majoris is a star in the northern constellation of Ursa Major. The designation is Latinised from ε Ursae Majoris and abbreviated Epsilon UMa or ε UMa. It is officially named Alioth. Despite being designated "ε" (epsilon), it is the brightest star in the constellation and at magnitude 1.77 is the thirty-third brightest star in the sky.

Beta Ursae Majoris, formally named Merak, is a star in the northern constellation of Ursa Major.

Psi Ursae Majoris is a star in the northern circumpolar constellation of Ursa Major. It has an apparent visual magnitude of +3.01, making it a third magnitude star and one of the brighter members of the constellation. Parallax measurements place it at a distance of 144.5 light-years from Earth. This is sufficiently close that the magnitude of the star is only reduced by 0.05 due to extinction. In Chinese astronomy, Psi Ursae Majoris is called Tien Tsan or Ta Tsun, "Extremely Honorable". The name was possibly derived from the word 太尊, Pinyin: Tàizūn, meaning Royals, because this star stands alone as the only member of the Royals asterism within the Purple Forbidden enclosure.

Theta Ursae Majoris is a suspected spectroscopic binary star system in the northern circumpolar constellation of Ursa Major. It has an apparent visual magnitude of 3.17, placing it among the brighter members of this constellation. The distance to this star has been measured directly using the parallax method, yielding an estimated value of 43.96 light-years.

Omicron Ursae Majoris, formally named Muscida, is a star system in the northern circumpolar constellation of Ursa Major. It has an apparent visual magnitude of +3.35 and is located at a distance of around 179 light-years from the Sun. In 2012, an extrasolar planet, designated Omicron Ursae Majoris Ab was found to be orbiting the primary.

Nu Ursae Majoris, formally named Alula Borealis, is a double star in the northern circumpolar constellation of Ursa Major. At an apparent visual magnitude of +3.490, it is bright enough to be seen with the naked eye. Based upon parallax measurements, the distance to ν Ursae Majoris is about 399 light-years.

<span class="mw-page-title-main">Upsilon Ursae Majoris</span> Binary star in the constellation Ursa Major

Upsilon Ursae Majoris, Latinized from υ Ursae Majoris, is a binary star in the northern circumpolar constellation of Ursa Major. It is visible to the naked eye with an apparent visual magnitude of +3.79. Based upon an annual parallax shift of 13.24 mas, it is located roughly 246 light-years from the Sun.

<span class="mw-page-title-main">Omega Ursae Majoris</span> Binary system in the constellation Ursa Major

Omega Ursae Majoris is the Bayer designation for a binary star system in the northern circumpolar constellation of Ursa Major. It is visible to the naked eye with an apparent visual magnitude of 4.61. Based upon an annual parallax shift of 13.24 mas, it is roughly 246 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.11 due to interstellar dust.

<span class="mw-page-title-main">Tau Ursae Majoris</span> Binary star in the constellation Ursa Major

Tau Ursae Majoris (τ UMa) is the Bayer designation for a binary star in the northern circumpolar constellation of Ursa Major. It is visible to the naked eye, having an apparent visual magnitude of 4.66. With an annual parallax shift of 25.82 mas, it is located about 126 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.19 due to interstellar dust.

<span class="mw-page-title-main">Rho Ursae Majoris</span> Solitary red giant star in the constellation Ursa Major

Rho Ursae Majoris (ρ UMa) is the Bayer designation for a solitary star in the northern circumpolar constellation of Ursa Major. It is faintly visible to the naked eye with an apparent visual magnitude of 4.74. The distance to this star, based upon an annual parallax shift of 10.37 mas, is around 315 light years.

4 Ursae Majoris (sometimes abbreviated 4 Uma) is the Flamsteed designation of a star in the northern circumpolar constellation of Ursa Major. It also bears the Bayer designation of Pi2 Ursae Majoris (Pi2 UMa, π2 Ursae Majoris, π2 UMa) and is traditionally named Muscida. With an apparent visual magnitude of +4.6, this star is visible from suburban or darker skies based upon the Bortle Dark-Sky Scale. From parallax measurements made during the Hipparcos mission, this star is at a distance of 256 light-years (78 parsecs) from Earth. As of 2011, one extrasolar planet has been confirmed to be orbiting the star.

<span class="mw-page-title-main">Theta Ursae Minoris</span> Suspected binary star in the constellation Ursa Minor

Theta Ursae Minoris, Latinized from θ Ursae Minoris, is a suspected binary star system that is visible to the naked eye in the northern circumpolar constellation of Ursa Minor. It is roughly 860 light years from Earth with an apparent visual magnitude of 5.0. The system is moving closer to the Sun with a radial velocity of −25 km/s.

<span class="mw-page-title-main">23 Ursae Majoris</span> Star in the constellation Ursa Major

23 Ursae Majoris, or 23 UMa, is a binary star system in the constellation Ursa Major, located is approximately 77.7 light years from the Sun. 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. It is moving closer to the Earth with a heliocentric radial velocity of −10 km/s.

<span class="mw-page-title-main">10 Canis Majoris</span> Star in the constellation Canis Major

10 Canis Majoris is a single variable star in the southern constellation of Canis Major, located roughly 1,980 light years away from the Sun. It has the variable star designation FT Canis Majoris; 10 Canis Majoris is the Flamsteed designation. This body is visible to the naked eye as a faint, blue-white hued star with a baseline apparent visual magnitude of 5.23. It is moving away from the Earth with a heliocentric radial velocity of +34 km/s.

Theta Ceti, Latinized from θ Ceti, is a solitary, orange-hued star in the equatorial constellation of Cetus. It is visible to the naked eye with an apparent visual magnitude of 3.60. Based upon an annual parallax shift of 28.66 mas as seen from Earth, it is located about 114 light-years from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.10 due to interstellar dust.

Phi Ursae Majoris, Latinized from φ Ursae Majoris, is binary star system in the northern constellation of Ursa Major. It is white-hued and is visible to the naked eye with a combined apparent visual magnitude of +4.60; the primary is magnitude 5.28 while the secondary is magnitude 5.39. The system is located at a distance of approximately 510 light-years from the Sun based on parallax, but is drifting closer with a radial velocity of −14.7 km/s. It should make its closest approach at a distance of around 370 light-years in about 4.7 million years.

<span class="mw-page-title-main">83 Ursae Majoris</span> Candidate binary star system in the constellation Ursa Major

83 Ursae Majoris is a candidate binary star system in the northern circumpolar constellation of Ursa Major. It is a semiregular variable star, and it has been given the variable star designation IQ Ursae Majoris. It ranges in brightness from apparent visual magnitude 4.69 to 4.75. Percy and Au (1994) identified it as a small amplitude red variable with an irregular behavior, having a characteristic time scale of 20 days. Based upon an annual parallax shift of 6.23±0.22 mas, it is located roughly 520 light years from the Sun. The distance derived from its Gaia Early Data Release 3 parallax is 179 pc. The system is moving closer with a heliocentric radial velocity of −18.6 km/s.

18 Ursae Majoris, or e Ursae Majoris, is a single star in the northern circumpolar constellation of Ursa Major. It is faintly visible to the naked eye with an apparent visual magnitude of 4.832. The annual parallax shift measured from Earth's orbit is 27.90 mas, which provides a distance estimate of 117 light years. It is moving closer to the Sun with a heliocentric radial velocity of −16 km/s, and is an unbound and older member of the Ursa Major Moving Group.

<span class="mw-page-title-main">65 Ursae Majoris</span> Star system in the constellation Ursa Major

65 Ursae Majoris, abbreviated as 65 UMa, is a star system in the constellation of Ursa Major. With a combined apparent magnitude of about 6.5, it is at the limit of human eyesight and is just barely visible to the naked eye in ideal conditions. It is about 760 light years away from Earth.

<span class="mw-page-title-main">TU Ursae Majoris</span>

TU Ursae Majoris is a variable star in the northern circumpolar constellation of Ursa Major. It is classified as a Bailey-type 'ab' RR Lyrae variable with a period of 0.557648 days that ranges in brightness from apparent visual magnitude of 9.26 down to 10.24. The distance to this star is approximately 2,090 light years based on parallax measurements. It is located near the north galactic pole at a distance that indicates this is a member of the galactic halo.

References

  1. 1 2 3 4 5 6 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. 1 2 3 4 5 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. 1 2 Sreedhar Rao, S.; Abhyankar, K. D. (1991). "MK morphological study of AM stars at 66 A/mm". Journal of Astrophysics and Astronomy. 12 (2): 133. Bibcode:1991JApA...12..133S. doi:10.1007/BF02709302. S2CID   59324843.
  4. ↑ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012). "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project". Astronomy & Astrophysics. 546: 14. arXiv: 1208.3048 . Bibcode:2012A&A...546A..61D. doi:10.1051/0004-6361/201219219. S2CID   59451347. A61.
  5. 1 2 3 De Rosa, R. J.; Patience, J.; Wilson, P. A.; Schneider, A.; Wiktorowicz, S. J.; Vigan, A.; Marois, C.; Song, I.; MacIntosh, B.; Graham, J. R.; Doyon, R.; Bessell, M. S.; Thomas, S.; Lai, O. (2014). "The VAST Survey - III. The multiplicity of A-type stars within 75 pc". Monthly Notices of the Royal Astronomical Society. 437 (2): 1216. arXiv: 1311.7141 . Bibcode:2014MNRAS.437.1216D. doi:10.1093/mnras/stt1932. S2CID   88503488.
  6. ↑ Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics (Third ed.), 367: 521–524, arXiv: astro-ph/0012289 , Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID   425754.
  7. 1 2 3 Prugniel, P.; et al. (2011). "The atmospheric parameters and spectral interpolator for the MILES stars". Astronomy & Astrophysics. 531: A165. arXiv: 1104.4952 . Bibcode:2011A&A...531A.165P. doi:10.1051/0004-6361/201116769. S2CID   54940439.
  8. ↑ Royer, F.; et al. (October 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", Astronomy and Astrophysics, 393 (3): 897–911, arXiv: astro-ph/0205255 , Bibcode:2002A&A...393..897R, doi:10.1051/0004-6361:20020943, S2CID   14070763
  9. ↑ "15 UMa". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-03-17.
  10. ↑ Nakajima, Tadashi; Morino, Jun-Ichi (2012). "Potential Members of Stellar Kinematic Groups within 30 pc of the Sun". The Astronomical Journal. 143 (1): 2. Bibcode:2012AJ....143....2N. doi: 10.1088/0004-6256/143/1/2 .
  11. ↑ Eggleton, P. P.; Tokovinin, A. A. (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.
  12. ↑ Allen, Richard Hinckley (1899), Star-Names and Their Meanings, New York: G. E. Stechert, p. 442
  13. ↑ 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.
  14. ↑ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 16 日
  15. ↑ Ian Ridpath's Startales - Ursa Major the Great Bear
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