IU Aurigae

IU Aurigae

A visual band light curve for IU Aurigae, adapted from Özdemir et al. (2003)[1]
Observation data Epoch J2000      Equinox J2000
Constellation	Auriga
Right ascension	05^h 27^m 52.40539^s[2]
Declination	+34° 46′ 58.3435″[2]
Apparent magnitude (V)	8.19 to 8.83[3]
Characteristics
Spectral type	B0p + B1Vp[3] + ?
U−B color index	-0.66
B−V color index	0.18
Variable type	Eclipsing binary[4]
Astrometry
Radial velocity (Rv)	9 ± 5 km/s
Proper motion (μ)	RA: −4.479[2] mas/yr Dec.: -9.049[2] mas/yr
Parallax (π)	0.4786 ± 0.5765 mas[2]
Other designations
IU Aur, BD+34°1051, HD 35652, HIP 25565, SAO 58059, PPM 70395[5]
Database references
SIMBAD	data

IU Aurigae is a triple star^[6] system in the constellation Auriga, consisting of an eclipsing binary pair orbiting a third component with a period of 335 years.^[7] This system is too faint to be viewed with the naked eye, having a peak apparent visual magnitude of 8.19.^[3]

Pavel Mayer discovered that the star's brightness varies in 1964.^[8] The eclipsing pair form a Beta Lyrae-type semidetached binary of two Bp stars^[3] with a period of 1.81147435 days.^[4] During the primary eclipse, the visual magnitude of the system drops to 8.89, while for the secondary it decreases to 8.74.^[3][9] The third component is a massive object with 17–18 M_☉, and may actually be a binary – which would make this a quadruple star system.^[7]

References

1. Özdemir, S.; Mayer, P.; Drechsel, H.; Demircan, O.; Ak, H. (May 2003). "Refinement of third body parameters and new photometric results for the early-type multiple system IU Aurigae". Astronomy & Astrophysics. 403 (2): 675–681. Bibcode:2003A&A...403..675O. doi:10.1051/0004-6361:20030392.
2. 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.
3. Avvakumova, E. A.; et al. (October 2013), "Eclipsing variables: Catalogue and classification", Astronomische Nachrichten, 334 (8): 860, Bibcode:2013AN....334..860A, doi:10.1002/asna.201311942, hdl:10995/27061
4. Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
5. "IU Aur". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-08-18.
6. Mayer, P.; Drechsel, H. (September 1987), "Up-to-date parameters of the eclipsing triple system IU AUR", Astronomy and Astrophysics, 183 (1): 61–65, Bibcode:1987A&A...183...61M.
7. Drechsel, H.; Haas, S.; Lorenz, R.; Mayer, P. (April 1994), "New photometric and spectroscopic results for IU Aurigae -- an early-type eclipsing binary in a multiple system", Astronomy and Astrophysics, 284 (3): 853–864, Bibcode:1994A&A...284..853D.
8. Mayer, P. (March 1964). "New Bright Early Type Eclipsing Variable" (PDF). Information Bulletin on Variable Stars. 49: 1. Bibcode:1964IBVS...49....1M. Retrieved 29 November 2024.
9. Watson, Christopher (January 4, 2010), "IU Aurigae", The International Variable Star Index, American Association of Variable Star Observers, retrieved 2019-08-18.