UX Arietis
(Redirected from HD 21242)
| 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] |
| Distance | 165 ± 1 ly (50.5 ± 0.3 pc) |
| Absolute magnitude (MV) | 2.91[8] |
| Orbit[9] | |
| Primary | Aa |
| Companion | Ab |
| 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] | |
| Primary | A |
| Companion | B |
| 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 | |
| Mass | 1.30±0.06 M☉ |
| Radius | 5.6±0.1 R☉ |
| Luminosity | 9.3±0.7 L☉ |
| Surface gravity (log g) | 3.06±0.04 cgs |
| Temperature | 4,560±100 K |
| Rotation | 6.44 d[4] |
| UX Ari Ab | |
| Mass | 1.14±0.06 M☉ |
| Radius | 1.6±0.2 R☉ |
| Luminosity | 2.34±0.28 L☉ |
| Surface gravity (log g) | 4.09±0.16 cgs |
| Temperature | 5,670±100 K |
| UX Ari B | |
| Mass | 0.75 M☉ |
| Radius | 0.8±0.1 R☉ |
| Luminosity | 0.38±0.08 L☉ |
| Surface gravity (log g) | 4.51±0.13 cgs |
| Temperature | 4,930±100 K |
| Other designations | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
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 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]
In 1972, Robert E. Montle and Douglas S. Hall discovered that the star's brightness varies.[11] It was given its variable star designation in 1973.[12] The primary, component Aa, is the 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]
A more distant companion, component C, shares a common proper motion and is at the same distance.[13] It is another cool dwarf star with an estimated spectral class of K2. Any orbit is estimated to require over 100,000 years.[14]
References
[edit]- ^ 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.
- ^ 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 "UX Ari". The International Variable Star Index. AAVSO. Retrieved 28 October 2021.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ Montle, R. E.; Hall, D. S. (March 1972). "HD 21242: a New Bright Variable Star" (PDF). Information Bulletin on Variable Stars. 646. Bibcode:1972IBVS..646....1M. Retrieved 28 November 2024.
- ^ Kukarkin, B. V.; Kholopov, P. N.; Kukarkina, N. P.; Perova, N. B. (October 1973). "59th Name-List of Variable Stars" (PDF). Information Bulletin on Variable Stars. 834. Bibcode:1973IBVS..834....1K. Retrieved 28 November 2024.
- ^ 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.
- ^ 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
[edit]- Brinkman, Albert (2000). "High-Resolution Spectrum of UX Ari". Chandra Proposal ID #02200030: 434. Bibcode:2000cxo..prop..434B.
- Drake, Stephen (1999). "Acis/hetg Spectroscopy of the Active Binaries Algol & UX Ari". Chandra Proposal ID #01200248: 20. Bibcode:1999cxo..prop...20D.
- V. Aarum Ulvås & G. W. Henry (2003). "BV photometry of UX Ari in the period 1987-2002". Astronomy and Astrophysics.
