Mu Boötis
  Location of μ Boötis (circled) | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 15h 24m 29.43147s[1] |
| Declination | +37° 22′ 37.7613″[1] |
| Apparent magnitude (V) | 4.31[2] |
| Characteristics | |
| Spectral type | F2IV[3] |
| U−B color index | +0.06[4] |
| B−V color index | +0.31[4] |
| R−I color index | 0.15 |
| Astrometry | |
| Radial velocity (Rv) | −8.60±0.3[5] km/s |
| Proper motion (μ) | RA: −149.928[1] mas/yr Dec.: +89.573[1] mas/yr |
| Parallax (π) | 26.5759±0.7871 mas[1] |
| Distance | 123 ± 4 ly (38 ± 1 pc) |
| Absolute magnitude (MV) | 1.47[6] |
| Orbit[3] | |
| Primary | Aa |
| Companion | Ab |
| Period (P) | 3.75 years |
| Semi-major axis (a) | 0.099″ |
| Eccentricity (e) | 0.270 |
| Inclination (i) | 129.7° |
| Longitude of the node (Ω) | 129.4° |
| Periastron epoch (T) | 1006.33 |
| Argument of periastron (ω) (secondary) | 43.5° |
| Details | |
| Aa | |
| Mass | 1.6[3] M☉ |
| Radius | 1.9[2] R☉ |
| Luminosity | 20[7] L☉ |
| Surface gravity (log g) | 3.4[3] cgs |
| Temperature | 7,000[3] K |
| Rotational velocity (v sin i) | 89[3] km/s |
| Ab | |
| Mass | 1.5[3] M☉ |
| Surface gravity (log g) | 3.6[3] cgs |
| Temperature | 7,000[3] K |
| Rotational velocity (v sin i) | 40[3] km/s |
| Other designations | |
| Alkalurops, Inkalunis, Icalurus, Clava, Venabulum, μ Boo, 51 Boötis, BD+37°2636, FK5 568, GC 20724, GJ 3903, HD 137391, HIP 75411, HR 5733, SAO 64686, ADS 9626, CCDM 15245+3722 | |
| Database references | |
| SIMBAD | data |
Mu Boötis is a binary star in the northern constellation of Boötes. Its name is a Bayer designation that is Latinized from μ Boötis, and abbreviated Mu Boo or μ Boo. This system had the traditional name Alkalurops, pronounced /ælkəˈljʊərɒps/.[8] Based on parallax measurements, these stars are located at a distance of 123 light-years.
It makes an optical double with Mu2 Boötis, 109" away, which is an unrelated star system passing close to Mu Boötis.
Properties
[edit]The components of the system have an angular separation of 0.10″.[9] They form a spectroscopic binary system with an orbital period of 3.75 years.[3] The visible component is a yellow-white F-type subgiant with an apparent magnitude of +4.31.
Additional components
[edit]More far away there is μ2 Boötis, a double star whose components are separated by 2.30″.[9] It is a probable binary star system with an apparent magnitude of +6.51. Their spectral classification of G1V matches a G-type main-sequence star. The components of μ2 Boötis have apparent magnitudes of +7.2 and +7.8.[citation needed] They complete one orbit about their common centre of mass every 260 years.[3]
μ1 and μ2 Boötis are separated by 109.2″ as of 2023,[9] with matching parallaxes and proper motions, suggesting they form a system. However, components BC have a different chemical composition compared to the A pair, confirming that they are actually be a close encounter between two binary systems.[3] Before being found to be separated systems, they were often called μ1 Boötis and μ2 Boötis, μ1 referring to components Aa and Ab, and μ1 referring to components and BC (or B).[9][3]
Nomenclature
[edit]μ Boötis (Latinised to Mu Boötis) is the star's Bayer designation. It also bears the Flamsteed designation 51 Boötis.
The system's traditional name Alkalurops is from the Greek καλαύροψ kalaurops "a herdsman's crook or staff", with the Arabic prefix attached.[10] It has also been known as Inkalunis (from the Alfonsine tables), Clava (Latin 'the club') and Venabulum (Latin 'a hunting spear').[11] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[12] to catalogue and standardize proper names for stars. The WGSN approved the name Alkalurops for μ¹ Boötis on 21 August 2016 and it is now so entered in the IAU Catalog of Star Names.[8]
It is known as 七公六, Qī Gōng liù (the Sixth Star of the Seven Excellencies) in Chinese.[13]
Gallery
[edit]-
Mu Bootis (Alkalurops) as seen in a small telescope -
Illustration of Mu1,2 Boötis
References
[edit]- ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b Malagnini, M. L.; Morossi, C. (November 1990), "Accurate absolute luminosities, effective temperatures, radii, masses and surface gravities for a selected sample of field stars", Astronomy and Astrophysics Supplement Series, 85 (3): 1015–1019, Bibcode:1990A&AS...85.1015M.
- ^ a b c d e f g h i j k l m n Kiyaeva, O. V.; et al. (November 2014), "The multiple system ADS 9626: A quadruple star or an encounter of two binaries?", Astronomy Reports, 58 (11): 835–848, Bibcode:2014ARep...58..835K, doi:10.1134/S106377291411002X, S2CID 122667185.
- ^ a b Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
- ^ Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
- ^ 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.
- ^ Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID 55586789.
- ^ a b Mamajek, Eric; et al. (June 30, 2017), IAU Catalog of Star Names, IAU Division C Working Group on Star Names, retrieved 28 July 2016.
- ^ a b c d Mason, Brian D.; et al. (2001), "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.
- ^ Allen, Richard H. (1963), Star Names: Their Lore and Meaning (Reprint ed.), New York: Dover Publications Inc, p. 97, ISBN 0-486-21079-0, retrieved 2016-09-15.
{{citation}}: CS1 maint: ignored ISBN errors (link) - ^ Allen, Richard H. (1963), Star Names: Their Lore and Meaning (Reprint ed.), New York: Dover Publications Inc, p. 105, ISBN 0-486-21079-0, retrieved 2016-09-15.
{{citation}}: CS1 maint: ignored ISBN errors (link) - ^ IAU Working Group on Star Names (WGSN), International Astronomical Union, retrieved 22 May 2016.
- ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 26 日 Archived 2011-05-22 at the Wayback Machine
