Third-nearest WZ Sge-Type dwarf nova candidate ASASSN-14dx classified on the basis of Gaia Data Release 2
Third-nearest WZ Sge-Type dwarf nova candidate ASASSN-14dx classified on the basis of Gaia Data Release 2
复制标题
第三个最近的 WZ Sge 型矮新星候选者 ASASSN-14dx 根据盖亚数据第 2 版分类
DOI：
10.1093/pasj/psy141
复制
发表时间：
2018
影响因子：
2.3
通讯作者：
Nogami Daisaku
中科院分区：
文献类型：
--
作者：
Isogai Keisuke;Kato Taichi;Imada Akira;Ohshima Tomohito;Kojiguchi Naoto;Ohnishi Ryuhei;Hambsch Franz-Josef;Monard Berto;Kiyota Seiichiro;Nishimura Hideo;Nogami Daisaku
ASASSN-14 dx观测到一次异常大爆发，其特点是爆发幅度小（12.3等），持续时间长（>4年）。因为我们发现了一个很长的观测间隙的123天前的爆发检测，我们建议，主要的爆发平台错过了，这次爆发只是一个“衰落的尾巴”后，经常看到的WZ Sge型超级爆发。为了区分WZ Sge和SU UMa型矮新星（DNe），我们对盖亚数据发布2（DR 2）进行了统计研究。我们应用逻辑回归模型，并成功地分类使用绝对盖亚星等MG和盖亚颜色GBP-GRP。我们的新分类器还表明ASASSN-14 dx是WZ Sge型DN的最佳候选者。我们估计距离已知的WZ Sge恒星地球使用盖亚DR 2的视差。结果表明，ASASSN-14 dx是距离WZ Sge第三近的星星（仅次于WZ Sge和V455 And），因此该天体可以显示出第三亮的WZ Sge型超爆发，其最大值为V = 8-9等。
ASASSN-14dx showed an extraordinary outburst whose features are a small outburst amplitude (∼2.3 mag) and long duration (>4 yr). Because we found a long observational gap of 123 d before the outburst detection, we propose that the main outburst plateau was missed and that this outburst is just a “fading tail” often seen after the WZ Sge-type super-outbursts. In order to distinguish between WZ Sge and SU UMa-type dwarf novae (DNe), we investigated Gaia Data Release 2 (DR2) statistically. We applied a logistic regression model and succeeded in classifying by using absolute Gaia magnitudesMGand Gaia colorsGBP–GRP. Our new classifier also suggests that ASASSN-14dx is the best candidate of a WZ Sge-type DN. We estimated distances from the Earth of known WZ Sge stars by using Gaia DR2 parallaxes. The result indicates that ASASSN-14dx is the third-nearest WZ Sge star (next to WZ Sge and V455 And), and hence the object can show the third-brightest WZ Sge-type super-outburst whose maximum isV= 8–9 mag.