HD 34626, also known as MZ Aurigae, is an unusual variable star in the northern constellation of Auriga. It has an apparent magnitude of 8.2 and is about 3,300 light years away.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Auriga |
| Right ascension | 05h 20m 33.03590s[2] |
| Declination | +36° 37′ 56.0306″[2] |
| Apparent magnitude (V) | 8.16[3] |
| Characteristics | |
| Spectral type | B1.5 IVnp[4] |
| U−B color index | −0.68[5] |
| B−V color index | +0.03[5] |
| Variable type | SX Ari?[6] |
| Astrometry | |
| Radial velocity (Rv) | −6[7] km/s |
| Proper motion (μ) | RA: −0.630[2] mas/yr Dec.: −4.017[2] mas/yr |
| Parallax (π) | 0.9831 ± 0.0356 mas[2] |
| Distance | 3,300 ± 100 ly (1,020 ± 40 pc) |
| Details | |
| Mass | 4.4[2] M☉ |
| Radius | 21[2] R☉ |
| Luminosity | 556[2] L☉ |
| Temperature | 22,675[3] K |
| Rotational velocity (v sin i) | 310[8] km/s |
| Age | 200[9] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The spectrum of HD 34626 had long been known to be unusual, with very broad lines indicating rapid rotation and emission lines marking it as a Be star. In 1970, it was found to vary in brightness by 0.1 magnitude over time scales of 8 to 12 hours, but these variations are not periodic.[10] This indicates the variability is not caused by ellipsoidal effects, and the nature of the variability remains unknown.[8] It may be a type of SX Arietis variable.[6]
HD 34626 has exhausted its core hydrogen and evolved away from the main sequence. Its spectral type indicates that it is a subgiant, but evolutionary models suggest it may be in the giant stage.[2]
References
edit- ^ Labadie-Bartz, Jonathan; Pepper, Joshua; McSwain, M. Virginia; Bjorkman, J. E.; Bjorkman, K. S.; Lund, Michael B.; Rodriguez, Joseph E.; Stassun, Keivan G.; Stevens, Daniel J.; James, David J.; Kuhn, Rudolf B.; Siverd, Robert J.; Beatty, Thomas G. (May 2017). "Photometric Variability of the Be Star Population". The Astronomical Journal. 153 (6): 252. arXiv:1609.08449. Bibcode:2017AJ....153..252L. doi:10.3847/1538-3881/aa6396. S2CID 119234382.
- ^ a b c d e f g h i 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 Hohle, M. M.; et al. (April 2010), "Masses and luminosities of O- and B-type stars and red supergiants", Astronomische Nachrichten, 331 (4): 349–360, arXiv:1003.2335, Bibcode:2010AN....331..349H, doi:10.1002/asna.200911355, S2CID 111387483
- ^ Walborn, N. R. (1971). "Some Spectroscopic Characteristics of the OB Stars: An Investigation of the Space Distribution of Certain OB Stars and the Reference Frame of the Classification". The Astrophysical Journal Supplement Series. 23: 257. Bibcode:1971ApJS...23..257W. doi:10.1086/190239.
- ^ a b Deutschman, W. A.; Davis, R. J.; Schild, R. E. (February 1976), "The galactic distribution of interstellar absorption as determined from the Celescope catalog of ultraviolet stellar observations and a new catalog of UBV, H-beta photoelectric observations", Astrophysical Journal Supplement Series, 30: 97–225, Bibcode:1976ApJS...30...97D, doi:10.1086/190359
- ^ a b "MZ Aur". International Variable Star Index. AAVSO. Retrieved 2022-09-27.
- ^ Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35 495 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.
- ^ a b Percy, J. R. (December 1984), "Five suspected Beta Cephei stars revisited", Journal of the Royal Astronomical Society of Canada, 78: 241–250, Bibcode:1984JRASC..78..241P
- ^ Tetzlaff, N.; Neuhäuser, R.; Hohle, M.M. (January 2011). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1): 190–200. arXiv:1007.4883. Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. S2CID 118629873.
- ^ Percy, J. R. (1970). "A photometric study of some early B stars whose spectral lines vary in sharpness". The Astronomical Journal. 75: 818. Bibcode:1970AJ.....75..818P. doi:10.1086/111026.