Variability in Protoplanetary Nebulae: X. Multi-year Periods as an Indicator of Potential Binaries
| Autor: | Hrivnak, Bruce J., Lu, Wenxian, Henson, Gary, Hillwig, Todd C. |
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| Rok vydání: | 2023 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | New observations are presented of four evolved objects that display long, multi-year variations in their light curves. These are interpreted as good evidence of their binary nature, with the modulation caused by the barycenter motion of the evolved star resulting in a periodic obscuration by a circumbinary disk. Although protoplanetary nebulae (PPNe) commonly possess bipolar nebulae, which are thought to be shaped by a binary companion, there are very few PPNe in which a binary companion has been found. Three of the objects in this study appear to be PPNe, IRAS 07253-2001, 08005-2356, and 17542-0603, with long periods of 5.2, 6.9, and 8.2 yrs, respectively. The binary nature of IRAS 08005-2356 has recently been confirmed by a radial velocity study. Two samples, one of PPNe and the other of post-AGB star candidates, are investigated for further evidence on how common is a long-period light curve variation. Both samples suggest such light variations are not common. The fourth object, IRAS 20056+1834 (QY Sge), is an obscured RV Tau variable of the RVb subclass, with a long period of 3.9 yrs and pulsation periods of 102.9 and 51.5 days. The period of this object is seen to vary by 2%. Evidence is presented for a recent mass ejection in IRAS 17542-0603. Comment: 22 pages, 6 figures, 1 machine-readable table |
| Databáze: | arXiv |
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