Astronomy:HD 33579
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Dorado |
| Right ascension | 5h 5m 55.51147s[2] |
| Declination | −67° 53′ 10.9330″[2] |
| Apparent magnitude (V) | 8.99 - 9.22[3] |
| Characteristics | |
| Spectral type | A3Ia+[4] |
| U−B color index | −0.29[5] |
| B−V color index | +0.14[5] |
| Variable type | α Cygni[6] |
| Astrometry | |
| Proper motion (μ) | RA: +1.810[2] mas/yr Dec.: +0.146[2] mas/yr |
| Parallax (π) | 0.0178 ± 0.0137[2] mas |
| Distance | approx. 200,000 ly (approx. 60,000 pc) |
| Absolute magnitude (MV) | −9.57[7] |
| Details | |
| Mass | 20–30[8] M☉ |
| Radius | 380[8] R☉ |
| Luminosity | 525,000[8] L☉ |
| Surface gravity (log g) | 0.82±0.21[4] cgs |
| Temperature | 7,980[8] K |
| Metallicity [Fe/H] | −0.38±0.14[4] dex |
| Other designations | |
HD 33579, CD−68 258, HIP 23718, R76, SK −67 44, AAVSO 0506-68 | |
| Database references | |
| SIMBAD | data |
HD 33579 is a white/yellow hypergiant and one of the brightest stars in the Large Magellanic Cloud (LMC). It is a suspected variable star.
HD 33579 lies in a part of the Hertzsprung–Russell diagram referred to as the Yellow Evolutionary Void because stars with that combination of luminosity and temperature are extremely unstable. They either expand to become cooler or shed their outer layers completely to become hotter. Yet HD 33579 is relatively stable, hardly even variable. This is thought to be due to its higher mass compared to most stars with similar temperature and luminosity.[4]
HD 33579 is an extremely rare type of star currently evolving for the first time through the yellow evolutionary void from being a blue hypergiant to becoming a red hypergiant. This means the star is often referred to as a yellow hypergiant although the spectral type of A3 means it is also described as a white hypergiant.[4]
Although HD 33579 has not been formally listed in the General Catalogue of Variable Stars, analysis of Hipparcos photometry confirmed small amplitude variations in its brightness that had been reported in earlier research.[9][10][11] Periods of 620 days and 105 days are found, plus other possible shorter periods. The total amplitude is only around 0.1 magnitudes.[6] A statistical analysis of Hipparcos photometry showed a possible period of 27 days.[12]
References
- ↑ "Hipparcos Tools Interactive Data Access". ESA. https://www.cosmos.esa.int/web/hipparcos/interactive-data-access.
- ↑ 2.0 2.1 2.2 2.3 2.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ "LMC V1006". AAVSO. https://www.aavso.org/vsx/index.php?view=detail.top&oid=235109.
- ↑ 4.0 4.1 4.2 4.3 4.4 Nieuwenhuijzen, H.; De Jager, C. (2000). "Checking the yellow evolutionary void. Three evolutionary critical Hypergiants: HD 33579, HR 8752 & IRC +10420". Astronomy and Astrophysics 353: 163–176 (2000). Bibcode: 2000A&A...353..163N.
- ↑ 5.0 5.1 Mavridis, L. N, ed (1974). Proceedings of the First European Astronomical Meeting Athens, September 4–9, 1972. doi:10.1007/978-3-642-65666-8. ISBN 978-3-642-65668-2.
- ↑ 6.0 6.1 Van Leeuwen, F.; Van Genderen, A. M.; Zegelaar, I. (1998). "Hipparcos photometry of 24 variable massive stars (α Cygni variables)". Astronomy and Astrophysics Supplement Series 128: 117–129. doi:10.1051/aas:1998129. Bibcode: 1998A&AS..128..117V.
- ↑ Bresolin, Fabio (2003). "Blue Supergiants as a Tool for Extragalactic Distances Empirical Diagnostics". Stellar Candles for the Extragalactic Distance Scale. Lecture Notes in Physics 635: 149–174. doi:10.1007/978-3-540-39882-0_8. ISBN 978-3-540-20128-1. Bibcode: 2003LNP...635..149B.
- ↑ 8.0 8.1 8.2 8.3 Yungelson, L. R.; Van Den Heuvel, E. P. J.; Vink, Jorick S.; Portegies Zwart, S. F.; De Koter, A. (2008). "On the evolution and fate of super-massive stars". Astronomy and Astrophysics 477 (1): 223–237. doi:10.1051/0004-6361:20078345. Bibcode: 2008A&A...477..223Y.
- ↑ Van Genderen, A. M. (1974). "A Probable Periodicity in the Light Variation of the LMC Supergiant HD 33579". Information Bulletin on Variable Stars 877: 1. Bibcode: 1974IBVS..877....1V.
- ↑ Van Genderen, A. M. (1979). "Long time baseline VBLUW photometry of four of the most luminous LMC supergiants HD 33579, HD 35343=S Dor, HDE 268757 and HDE 269006. I". Astronomy and Astrophysics Supplement Series 38: 151. Bibcode: 1979A&AS...38..151V.
- ↑ Grieve, G. R.; Madore, B. F.; Welch, D. L. (1985). "Leavitt variables—Bright variable supergiants and their implications for the distance scale". Astrophysical Journal 294: 513. doi:10.1086/163318. Bibcode: 1985ApJ...294..513G.
- ↑ Koen, Chris; Eyer, Laurent (2002). "New periodic variables from the Hipparcos epoch photometry". Monthly Notices of the Royal Astronomical Society 331 (1): 45–59. doi:10.1046/j.1365-8711.2002.05150.x. Bibcode: 2002MNRAS.331...45K.
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