Report
The path to Z And-type outbursts: The case of V426 Sagittae (HBHA 1704-05)
| العنوان: | The path to Z And-type outbursts: The case of V426 Sagittae (HBHA 1704-05) |
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| المؤلفون: | Skopal, A., Shugarov, S. Yu., Munari, U., Masetti, N., Marchesini, E., Komzik, R. M., Kundra, E., Shagatova, N., Tarasova, T. N., Buil, C., Boussin, C., Shenavrin, V. I., Hambsch, F. -J., Dallaporta, S., Frigo, A., Garde, O., Zubareva, A., Dubovský, P. A., Kroll, P. |
| المصدر: | A&A 636, A77 (2020) |
| سنة النشر: | 2020 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Solar and Stellar Astrophysics, Astrophysics - High Energy Astrophysical Phenomena |
| الوصف: | The star V426 Sge (HBHA~1704-05), originally classified as an emission-line object and a semi-regular variable, brightened at the beginning of August 2018, showing signatures of a symbiotic star outburst. We aim to confirm the nature of V426 Sge as a classical symbiotic star, determine the photometric ephemeris of the light minima, and suggest the path from its 1968 symbiotic nova outburst to the following 2018 Z And-type outburst. We re-constructed an historical light curve (LC) of V426 Sge from approximately the year 1900, and used original low- and high-resolution spectroscopy complemented with Swift-XRT and UVOT, optical UBVRcIc and near-infrared JHKL photometry obtained during the 2018 outburst and the following quiescence. The historical LC reveals no symbiotic-like activity from 1900 to 1967. In 1968, V426 Sge experienced a symbiotic nova outburst that ceased around 1990. From approximately 1972, a wave-like orbitally related variation with a period of $493.4\pm 0.7$ days developed in the LC. This was interrupted by a Z And-type outburst from the beginning of August 2018 to the middle of February 2019. At the maximum of the 2018 outburst, the burning white dwarf (WD) increased its temperature to $>2\times 10^5$ K, generated a luminosity of $\sim 7\times 10^{37}(d/3.3kpc)^2$ erg/s, and blew a wind at the rate of $\sim 3\times 10^{-6}$ M$_{\odot}$/yr. The donor is a normal M4-5 III giant and the accretor is a low-mass $\sim$0.5 M$_{\odot}$ WD. During the transition from the symbiotic nova outburst to the quiescent phase, a pronounced sinusoidal variation along the orbit develops in the LC of most symbiotic novae. The following eventual outburst is of Z And-type, when the accretion by the WD temporarily exceeds the upper limit of the stable burning. At this point the system becomes a classical symbiotic star. Comment: 19 pages, 12 figures, 9 tables, 2 appendices, accepted for A&A, Tables A.1, A.2 and A.3 are only available at the CDS, added references for section 1 |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1051/0004-6361/201937199 |
| URL الوصول: | http://arxiv.org/abs/2003.10135 |
| رقم الانضمام: | edsarx.2003.10135 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1051/0004-6361/201937199 |
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