Rho Ursae Majoris

Rho Ursae Majoris
	Location of ρ Ursae Majoris (circled)
Observation data; Epoch J2000.0 Equinox J2000.0 ( ICRS)
Constellation	Ursa Major
Right ascension	09h 02m 32.69092s
Declination	+67° 37′ 46.6280″
Apparent magnitude (V)	4.74
Characteristics
Spectral type	M3 III
U−B color index	+1.84
B−V color index	+1.56
Astrometry
Radial velocity (Rv)	4.75±0.19 km/s
Proper motion (μ)	RA: −22.83 mas/ yr ; Dec.: +18.13 mas/ yr
Parallax (π)	10.37 ± 0.25 mas
Distance	315 ± 8 ly ; (96 ± 2 pc)
Absolute magnitude (MV)	+0.06
Details
Radius	58 R☉
Luminosity	464 L☉
Temperature	3,725 K
Other designations
	ρ UMa, 8 Ursae Majoris, BD+68°551, FK5 338, HD 76827, HIP 44390, HR 3576, SAO 14742
Database references
SIMBAD	data

Rho Ursae Majoris (ρ UMa) is the Bayer designation for a solitary^[9] 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.^[2] The distance to this star, based upon an annual parallax shift of 10.37 mas,^[1] is around 315 light years.

With a stellar classification of M3 III,^[3] this is a red giant star on the asymptotic giant branch.^[10] It is a suspected small amplitude variable.^[11] The measured angular diameter of the star after correcting for limb darkening is 5.64±0.15 mas,^[12] which, at the estimated distance of this star, yields a physical size of about 58 times the radius of the Sun.^[6] It is radiating 464 times the solar luminosity from its outer atmosphere at an effective temperature of about 3,725 K.^[7] Based upon its motion through space, there is a 60.6% chance that this star is a member of the Sirius stream.^[5]

Naming

With π¹, π², σ¹, σ², A and d, it composed the Arabic asterism Al Ṭhibā᾽, the Gazelle.^[13] According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, Al Ṭhibā were the title for seven stars : A as Althiba I, π¹ as Althiba II, π² as Althiba III, this star (ρ) as Althiba IV, σ¹ as Althiba V, σ² as Althiba VI, and d as Althiba VII^[14]
In Chinese, 三師 (Sān Shī), meaning Three Top Instructors, refers to an asterism consisting of ρ Ursae Majoris and σ² Ursae Majoris. Consequently, the Chinese name for ρ Ursae Majoris itself is 三師一 (Sān Shī yī, English: the First Star of Three Top Instructors.).^[15]

References

^ ^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.
^ ^a ^b ^c ^d Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode: 1986EgUBV........0M.
^ ^a ^b Marrese, P. M.; et al. (August 2003), "High resolution spectroscopy over lambda lambda 8500-8750 Å for GAIA. IV. Extending the cool MK stars sample", Astronomy and Astrophysics, 406: 995–999, Bibcode: 2003A&A...406..995M, doi: 10.1051/0004-6361:20030647.
^ 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.
^ ^a ^b Famaey, B.; et al. (January 2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics, 430 (1): 165–186, arXiv: astro-ph/0409579, Bibcode: 2005A&A...430..165F, doi: 10.1051/0004-6361:20041272, S2CID 17804304.
^ ^a ^b Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, vol. 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1. The radius (R_*) is given by:
${\begin{aligned}2\cdot R_{*}&={\frac {(96.4\cdot 5.64\cdot 10^{-3})\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{\bigodot }}}\\&\approx 116.9\cdot R_{\bigodot }\end{aligned}}$
^ ^a ^b ^c McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv: 1208.2037, Bibcode: 2012MNRAS.427..343M, doi: 10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
^ "rho UMa". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-02-25.{{ cite web}}: CS1 maint: postscript ( link)
^ 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.
^ Eggen, O. J. (1992), "Asymptotic giant branch stars near the sun", The Astronomical Journal, 104: 275, Bibcode: 1992AJ....104..275E, doi: 10.1086/116239.
^ Percy, J. R.; et al. (1994), "Photometric surveys of suspected small-amplitude red variables. III: An AAVSO photometric photometry survey", Astronomical Society of the Pacific, 106 (700): 611–615, Bibcode: 1994PASP..106..611P, doi: 10.1086/133420.
^ Richichi, A.; et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777, Bibcode: 2005A&A...431..773R, doi: 10.1051/0004-6361:20042039.
^ Allen, Richard Hinckley (1899), Star-Names and Their Meanings, New York: G. E. Stechert, p. 444
^ 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.
^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 16 日

[vanLeeuwen2007-1] ^ ^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.

[Mermilliod1986-2] Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode: 1986EgUBV........0M.

[Marrese2003-3] Marrese, P. M.; et al. (August 2003), "High resolution spectroscopy over lambda lambda 8500-8750 Å for GAIA. IV. Extending the cool MK stars sample", Astronomy and Astrophysics, 406: 995–999, Bibcode: 2003A&A...406..995M, doi: 10.1051/0004-6361:20030647.

[deBruijne2012-4] 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.

[Famaey2005-5] Famaey, B.; et al. (January 2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics, 430 (1): 165–186, arXiv: astro-ph/0409579, Bibcode: 2005A&A...430..165F, doi: 10.1051/0004-6361:20041272, S2CID 17804304.

[lang2006-6] Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, vol. 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1. The radius (R_*) is given by:
${\begin{aligned}2\cdot R_{*}&={\frac {(96.4\cdot 5.64\cdot 10^{-3})\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{\bigodot }}}\\&\approx 116.9\cdot R_{\bigodot }\end{aligned}}$

[Mcdonald2012-7] McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv: 1208.2037, Bibcode: 2012MNRAS.427..343M, doi: 10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.

[SIMBAD-8] "rho UMa". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-02-25.{{ cite web}}: CS1 maint: postscript ( link)

[Eggleton2008-9] 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.

[Eggen1992-10] Eggen, O. J. (1992), "Asymptotic giant branch stars near the sun", The Astronomical Journal, 104: 275, Bibcode: 1992AJ....104..275E, doi: 10.1086/116239.

[Percy1994-11] Percy, J. R.; et al. (1994), "Photometric surveys of suspected small-amplitude red variables. III: An AAVSO photometric photometry survey", Astronomical Society of the Pacific, 106 (700): 611–615, Bibcode: 1994PASP..106..611P, doi: 10.1086/133420.

[Richichi2005-12] Richichi, A.; et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777, Bibcode: 2005A&A...431..773R, doi: 10.1051/0004-6361:20042039.

[allen1899-13] Allen, Richard Hinckley (1899), Star-Names and Their Meanings, New York: G. E. Stechert, p. 444

[rhoads1971-14] 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.

[15] (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 16 日

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13]

[14]

[15]

Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS)
Location of ρ Ursae Majoris (circled)
Constellation	Ursa Major
Right ascension	09^h 02^m 32.69092^s^[1]
Declination	+67° 37′ 46.6280″^[1]
Apparent magnitude (V)	4.74^[2]
Characteristics
Spectral type	M3 III^[3]
U−B color index	+1.84^[2]
B−V color index	+1.56^[2]
Astrometry

Radial velocity (R_v)	4.75±0.19^[4] km/s
Proper motion (μ)	RA: −22.83^[1] mas/ yr Dec.: +18.13^[1] mas/ yr
Parallax (π)	10.37 ± 0.25 mas^[1]
Distance	315 ± 8 ly (96 ± 2 pc)
Absolute magnitude (M_V)	+0.06^[5]

Details

Radius	58^[6] `R`_☉
Luminosity	464^[7] `L`_☉
Temperature	3,725^[7] K

Other designations
ρ UMa, 8 Ursae Majoris, BD+68°551, FK5 338, HD 76827, HIP 44390, HR 3576, SAO 14742^[8]
Database references
SIMBAD	data