V1309 Scorpii: merger of a contact binary
V1309 Scorpii: merger of a contact binary
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DOI：
10.1051/0004-6361/201016221
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发表时间：
2010-12
影响因子：
6.5
通讯作者：
R. Tylenda;M. Hajduk;T. Kamiński;A. Udalski;I. Soszyński;M. Szymański;M. Kubiak;G. Pietrzyński
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文献类型：
--
作者：
R. Tylenda;M. Hajduk;T. Kamiński;A. Udalski;I. Soszyński;M. Szymański;M. Kubiak;G. Pietrzyński
上下文在恒星系统的演化过程中，恒星的合并可能会在许多情况下发生。特别是，它们被认为是V838 Mon型恒星爆发的可能起源。V 1309 Sco是我们银河系中最近的一次此类喷发。该天体于2008年9月被发现。目标。我们的目的是研究V1309 Sco的性质。方法. V 1309 Sco自2001年8月以来一直在OGLE项目中进行光度测量。我们以不同的方式分析这些观察结果。特别是，进行周期图分析，以研究所观察到的祖细胞的短期变异性的性质。结果我们发现V1309Sco的前身是一颗轨道周期为1.4天的接触双星。这一时期随着时间的推移而减少。双星的光变曲线也在演化，表明系统正朝着合并的方向演化。合并的剧烈阶段，以物体的系统变亮为标志，开始于2008年3月，即爆发发现前半年。我们还调查了观测V 1309斯科在爆发和下降，并表明，它们可以完全占合并假说。结论.对于第一次在文献中，我们表明，从直接的观察，接触双星确实最终合并成一个单一的对象，在这些系统的许多理论研究所建议的。我们的研究还表明，恒星合并确实会导致V838 Mon类型的爆发。
Context. Stellar mergers are expected to take place in numerous circumstences in the evolution of stellar systems. In particular, they are considered as a plausible origin of stellar eruptions of the V838 Mon type. V 1309 Sco is the most recent eruption of this type in our Galaxy. The object was discovered in September 2008. Aims. Our aim is to investigate the nature of V 1309 Sco. Methods. V 1309 Sco has been photometrically observed in course of the OGLE project since August 2001. We analyse these observations in different ways. In particular, periodogram analyses were done to investigate the nature of the observed short-term variability of the progenitor. Results. We find that the progenitor of V 1309 Sco was a contact binary with an orbital period of ∼1.4 day. This period was decreasing with time. The light curve of the binary was also evolving, indicating that the system evolved towards its merger. The violent phase of the merger, marked by the systematic brightenning of the object, began in March 2008, i.e. half a year before the outburst discovery. We also investigate the observations of V 1309 Sco during the outburst and the decline and show that they can be fully accounted for within the merger hypothesis. Conclusions. For the first time in the literature we show from direct observations that contact binaries indeed end up by merging into a single object, as was suggested in numerous theoretical studies of these systems. Our study also shows that stellar mergers indeed result in eruptions of the V838 Mon type.