UX Arietis

(Redirected from HD 21242)

UX Arietis is a triple star system located in the northern zodiacal constellation of Aries. Based upon parallax measurements from the Gaia satellite, it is roughly 165 light years away. The primary, component Aa, is a variable star of the RS CVn type. The variability of the star is believed due to a combination of cool star spots and warm flares, set against the baseline quiescent temperature of the stellar atmosphere. The variability appears to be cyclical with a period of 8−9 years.[6] The star varies in brightness from magnitude 6.35 to 6.71, meaning it may be intermittently visible to the unaided eye under ideal dark-sky conditions.[3]

UX Arietis

A visual band light curve for UX Arietis, adapted from Ulvås and Henry (2003)[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Aries
Right ascension 03h 26m 35.37568s[2]
Declination +28° 42′ 54.2264″[2]
Apparent magnitude (V) 6.35 - 6.71[3]
Characteristics
Spectral type G5IV[4]
U−B color index 0.43[5]
B−V color index 0.90[5]
Variable type RS CVn[6]
Astrometry
Radial velocity (Rv)+26.53[7] km/s
Proper motion (μ) RA: +46.794[2] mas/yr
Dec.: −102.876[2] mas/yr
Parallax (π)19.7836 ± 0.1264 mas[2]
Distance165 ± 1 ly
(50.5 ± 0.3 pc)
Absolute magnitude (MV)2.91[8]
Orbit[9]
PrimaryAa
CompanionAb
Period (P)6.437888±0.000007 d
Semi-major axis (a)1.750±0.01 mas
Eccentricity (e)0 (fixed)
Inclination (i)125.0±0.5°
Longitude of the node (Ω)113.4±0.4°
Periastron epoch (T)2456238.134 ± 0.002 HJD
Argument of periastron (ω)
(secondary)
90 (fixed)°
Orbit[10]
PrimaryA
CompanionB
Period (P)111.02 yr
Semi-major axis (a)648.0±0.8 mas
Eccentricity (e)0.77±0.01
Inclination (i)93.3±0.6°
Longitude of the node (Ω)58.9±0.5°
Periastron epoch (T)2451664.9±34.3 HJD
Argument of periastron (ω)
(secondary)
274.9±0.8°
Details[9]
UX Ari Aa
Mass1.30±0.06 M
Radius5.6±0.1 R
Luminosity9.3±0.7 L
Surface gravity (log g)3.06±0.04 cgs
Temperature4,560±100 K
Rotation6.44 d[4]
UX Ari Ab
Mass1.14±0.06 M
Radius1.6±0.2 R
Luminosity2.34±0.28 L
Surface gravity (log g)4.09±0.16 cgs
Temperature5,670±100 K
UX Ari B
Mass0.75 M
Radius0.8±0.1 R
Luminosity0.38±0.08 L
Surface gravity (log g)4.51±0.13 cgs
Temperature4,930±100 K
Other designations
BD+28°532, CCDM 03266+2843, HD 21242, HIP 16042, SAO 75927
Database references
SIMBADdata
ARICNSdata

A more distant companion, component C, shares a common proper motion and is at the same distance.[11] It is another cool dwarf star with an estimated spectral class of K2. Any orbit is estimated to require over 100,000 years.[12]

References

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  1. ^ Ulvås, V. Aarum; Henry, G. W. (May 2003). "BV photometry of UX Ari in the period 1987–2002". Astronomy & Astrophysics. 402 (3): 1033–1041. Bibcode:2003A&A...402.1033A. doi:10.1051/0004-6361:20030304.
  2. ^ 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.
  3. ^ a b "UX Ari". The International Variable Star Index. AAVSO. Retrieved 28 October 2021.
  4. ^ a b Strassmeier, Klaus G. (September 2009). "Starspots". The Astronomy and Astrophysics Review. 17 (3): 251–308. Bibcode:2009A&ARv..17..251S. doi:10.1007/s00159-009-0020-6.
  5. ^ a b Guetter, H. H.; Hewitt, A. V. (June 1984). "Photoelectric UBV photometry for 317 PZT and VZT stars". Publications of the Astronomical Society of the Pacific. 96: 441–443. Bibcode:1984PASP...96..441G. doi:10.1086/131362.
  6. ^ a b Alekseev, I. Yu. (September 2014). "Three-Component Model of Spottedness in the Classical RS CVn System UX Ari". Astrophysics. 57 (3): 344–351. Bibcode:2014Ap.....57..344A. doi:10.1007/s10511-014-9339-4. S2CID 119963417.
  7. ^ Karataș, Yüksel; Bilir, Selçuk; Eker, Zeki; Demircan, Osman; Liebert, James; Hawley, Suzanne L.; Fraser, Oliver J.; Covey, Kevin R.; Lowrance, Patrick; Kirkpatrick, J. Davy; Burgasser, Adam J. (2004). "Kinematics of chromospherically active binaries and evidence of an orbital period decrease in binary evolution". Monthly Notices of the Royal Astronomical Society. 349 (3): 1069–1092. arXiv:astro-ph/0404219. Bibcode:2004MNRAS.349.1069K. doi:10.1111/j.1365-2966.2004.07588.x. S2CID 15290475.
  8. ^ Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. eISSN 1562-6873. ISSN 1063-7737. S2CID 119257644.
  9. ^ a b Hummel, C. A.; et al. (August 2017). "Orbital Elements and Stellar Parameters of the Active Binary UX Arietis". The Astrophysical Journal. 844 (2): 12. Bibcode:2017ApJ...844..115H. doi:10.3847/1538-4357/aa7b87. hdl:10871/32318. S2CID 43383613. 115.
  10. ^ Peterson, W. M.; Mutel, R. L.; Lestrade, J. -F.; Güdel, M.; Goss, W. M. (2011). "Radio Astrometry of the Triple Systems Algol and UX Arietis". The Astrophysical Journal. 737 (2): 104. arXiv:1104.5005. Bibcode:2011ApJ...737..104P. doi:10.1088/0004-637X/737/2/104. S2CID 119229905.
  11. ^ 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.
  12. ^ Tokovinin, Andrei (2018-03-01). "The Updated Multiple Star Catalog". The Astrophysical Journal Supplement Series. 235 (1): 6. arXiv:1712.04750. Bibcode:2018ApJS..235....6T. doi:10.3847/1538-4365/aaa1a5. ISSN 0067-0049. S2CID 119047709.

Further reading

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