OAO/MITSuME photometry of dwarf novae. II. HV?Virginis and OT?J012059.6+325545
OAO/MITSuME photometry of dwarf novae. II. HV?Virginis and OT?J012059.6+325545
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矮新星的 OAO/MITSUME 光度测定。
DOI：
10.1093/pasj/psx142
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发表时间：
2018
影响因子：
2.3
通讯作者：
Kawai Nobuyuki
中科院分区：
文献类型：
--
作者：
Imada Akira;Isogai Keisuke;raki Takahiro;Tanada Shunsuke;Yanagisawa Kenshi;Kawai Nobuyuki
本文报道了WZ型Sge型矮新星HV Vir和OT J012059.6+325545在超爆发期间的射电测光。这些系统显示出早期的超级峰，HV Vir的平均周期为0.057093（45）d，OT J012059.6+325545的平均周期为0.057147（15）d。观测到的早期超峰显示出一个共同的特征，即亮度最小值对应于颜色变化中最蓝的峰，这可能是WZ Sge型矮新星早期超峰中普遍存在的现象。我们证实，早期的超级驼峰的振幅依赖于波长：振幅与较长的带通滤波器显示较大的值。这表明早期超峰的光源产生于垂直扩展吸积盘的外部区域。另一方面，普通超级峰的振幅可能与波长无关。这意味着超级驼峰光源在几何上是薄的。我们还研究了普通超级峰的颜色变化，发现在λ-Ic中最蓝的峰往往与亮度最小值相一致，特别是在B阶段的超级峰中。这可能反映了在B阶段超峰期间压力效应起主导作用。
We report on multicolor photometry of WZ Sge-type dwarf novae HV Vir and OT J012059.6+325545 during superoutbursts. These systems show early superhumps with mean periods of 0.057093(45) d for HV Vir and 0.057147(15) d for OT J012059.6+325545. The observed early superhumps showed a common feature that the brightness minima corresponded to the bluest peaks in color variations, which may be a ubiquitous phenomenon among early superhumps of WZ Sge-type dwarf novae. We confirmed that the amplitudes of early superhumps depend on wavelength: amplitudes with longer bandpass filters show larger values. This indicates that the light source of early superhumps is generated at the outer region of the vertically extended accretion disk. On the other hand, amplitudes of ordinary superhumps are likely to be independent of wavelength. This implies that the superhump light source is geometrically thin. We also examined color variations of ordinary superhumps and found that the bluest peaks ing΄ −Ictend to coincide with the brightness minima, particularily in stage B superhumps. This may reflect that the pressure effect plays a dominant role during stage B superhumps.