Jump to content

Nu2 Boötis

From Wikipedia, the free encyclopedia
(Redirected from Ν2 Bootis)
Nu2 Boötis

ν1 (right) and ν2 (left) Boötis in optical light
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Boötes
Right ascension 15h 31m 46.98170s[1]
Declination +40° 53′ 57.5405″[1]
Apparent magnitude (V) 5.02[2] (5.80 + 5.80)[3]
Characteristics
Spectral type A5 V[4]
U−B color index +0.11[2]
B−V color index +0.07[2]
R−I color index 0.04
Astrometry
Radial velocity (Rv)−16.6±3.7[5] km/s
Proper motion (μ) RA: -21.905[1] mas/yr
Dec.: -7.876[1] mas/yr
Parallax (π)7.8618 ± 0.1449 mas[1]
Distance415 ± 8 ly
(127 ± 2 pc)
Absolute magnitude (MV)−0.59[6]
Orbit[7]
Period (P)9.026±0.017 yr
Semi-major axis (a)0.0615±0.0007
Eccentricity (e)0.006±0.015
Inclination (i)109.7±1.2°
Longitude of the node (Ω)199.4±0.9°
Periastron epoch (T)2000.75±0.24
Argument of periastron (ω)
(secondary)
293±9°
Details
Mass2.84±0.11[8] M
Radius6.21+1.07
−0.81
[1] R
Luminosity135±3[1] L
Temperature7894+574
−600
[1] K
Rotational velocity (v sin i)217[8] km/s
Other designations
ν2 Boo, ψ2 Her, 53 Boötis, BD+41° 2611, GC 20883, HD 138629, HIP 76041, HR 5774, SAO 45590, ADS 9688, CCDM 15318+4054, WDS J15318+4054AB[9]
Database references
SIMBADdata
Data sources:
Hipparcos Catalogue,
CCDM (2002),
Bright Star Catalogue (5th rev. ed.)

Nu2 Boötis is a white-hued binary star[10] system in the northern constellation of Boötes. It is faintly visible to the naked eye with a combined apparent visual magnitude of 5.02.[2] Based upon an annual parallax shift of 7.86 mas as seen from the Earth,[1] it is located roughly 415 light years from the Sun. The system is moving closer to the Sun with a radial velocity of −16.6 km/s.[5]

This stellar pair have a nearly circular orbit with a period of nine years and a semimajor axis of 0.0615 arc seconds.[10] They are both of visual magnitude 5.80 and display a similar spectrum, with the primary, component A, being an A-type main sequence star with a stellar classification of A5 V.[4] This has been identified as an A-type shell star, suggesting there is a circumstellar disk of gas orbiting one or both stars.[11] There are two other stars that appear close to the pair, termed C and D, but they are physically unrelated.[12]

Ptolemy considered Nu2 Boötis to be shared by Hercules, and Bayer assigned it a designation in both constellations: Nu2 Boötis (ν2 Boo) and Psi2 Herculis (ψ2 Her). When the modern constellation boundaries were fixed in 1930, the latter designation dropped from use.[13]

References

[edit]
  1. ^ a b c d e f g h i 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.
  2. ^ a b c d 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.
  3. ^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920
  4. ^ a b Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819.
  5. ^ a b 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.
  6. ^ 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.
  7. ^ Hartkopf, W. I.; et al. (June 30, 2006), Sixth Catalog of Orbits of Visual Binary Stars, United States Naval Observatory, archived from the original on 2017-08-01, retrieved 2017-09-13.
  8. ^ a b Zorec, J.; Royer, F. (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.
  9. ^ "nu02 Boo". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-09-09.
  10. ^ a b 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.
  11. ^ Hauck, B.; Jaschek, C. (February 2000), "A-shell stars in the Geneva system", Astronomy and Astrophysics, 354: 157–162, Bibcode:2000A&A...354..157H.
  12. ^ Hutter, D. J.; Tycner, C.; Zavala, R. T.; Benson, J. A.; Hummel, C. A.; Zirm, H. (2021). "Surveying the Bright Stars by Optical Interferometry. III. A Magnitude-limited Multiplicity Survey of Classical Be Stars". The Astrophysical Journal Supplement Series. 257 (2): 69. arXiv:2109.06839. Bibcode:2021ApJS..257...69H. doi:10.3847/1538-4365/ac23cb. S2CID 237503492.
  13. ^ "Bayer's Uranometria and Bayer letters". Archived from the original on 2019-03-15. Retrieved 2012-05-18.
[edit]
  • Hoffleit; et al. (1991), "HR 5774", Bright Star Catalogue (5th Revised ed.), retrieved 2017-09-13.
  • "Nu2 Boötis", Aladin previewer, Centre de Données astronomiques de Strasbourg, retrieved 2017-09-12.