论文标题
IW和Star V507 Cyg中的持久停滞和褪色的情节
Long-lasting standstill and fading episode in the IW And star V507 Cyg
论文作者
论文摘要
我们使用ASAS-SN数据，ZTF数据和快照光度法研究了IW和Star V507 CYG。该星星在2020年5月至2022年3月（现在仍在继续）。在过去的文献中，在其他一些IW和明星中发现了如此长期的停滞。我们发现，在2018年3月至2019年1月之间，该系统在0.3 MAG上是系统地淡淡的，当时它显示了包括IW和型状态在内的矮nova型变体。这是最明确的证据之一，即Z CAM星中的矮nova型状态（从广义上讲）与质量转移率的降低有关（在这种情况下为300 d的时间约为25％）。该物体还显示了2019年的IW和型现象，当时该系统与当前长时间停滞一样明亮。这一发现表明，在相同的质量转移速率下，IW和型现象是否出现的条件是微妙的。
We studied the IW And star V507 Cyg using ASAS-SN data, ZTF data and our snapshot photometry. The star has been found to be in a long standstill in 2020 May-2022 March (and it still continues now). Such long-lasting standstills have been found in a few other IW And stars in the past literature. We found that this system was systematically fainter by 0.3 mag between 2018 March and 2019 January when it showed dwarf nova-type variations, including IW And-type states. This is one of the clearest pieces of evidence that the dwarf nova-type state in Z Cam stars (in a broader sense) is associated with a decrease in the mass-transfer rate (~25% for a duration of 300 d in this case). The object also showed IW And-type phenomena in 2019, when the system was as bright as in the current long standstill. This finding suggests that the condition whether the IW And-type phenomenon occurs or not is subtle under the same mass-transfer rate.
