An analysis is presented of photometric observations of the intermediate polar DO Dra obtained during an epoch of significant reduction in its outburst activity for different average brightnesses of the system: 13 m .6-12 m .8 (2008) and 14 m .7-14 m .3 (2019). The observations in 2008 were made in the Johnson BVR system and in 2019, in integrated light. For the first time in quasi-simultaneous observations in the BVR bands, orbital modulation of the brightness was recorded in the form of a two-humped curve in each band, presumably caused by ellipsoidality of the secondary component. For six nights in the BVR bands (2008) and one night in integrated light (2019), stable quasiperiodic oscillations around 0.02 days were observed. On the night of JD 2458575 (2019) an increase in the brightness by 0 m .7 was observed over 3 min, followed by exponential decay. The flare lasted about an hour within the first half of which oscillations with a period of about 0.006 days and an amplitude of 0 m .1 were observed that may be related either to the rotation period of the white dwarf or to the quasiperiodic oscillations. The nature of the flare is not yet clear and possible reasons for this effect are examined in this article.

中文翻译：

---

2008 年和 2019 年中极地 DO Dra 的光度学研究

对中间极地 DO Dra 在其爆发活动显着减少时期获得的光度观测结果进行了分析，该时期系统的不同平均亮度为：13 m .6-12 m .8 (2008) 和 14 m .7- 14 m .3 (2019)。2008 年的观测是在 Johnson BVR 系统中进行的，2019 年是在集成光中进行的。在 BVR 波段的准同时观测中，第一次在每个波段以双峰曲线的形式记录了亮度的轨道调制，这可能是由次级分量的椭球性引起的。在 BVR 波段（2008 年）的六晚和综合光（2019 年）的一晚，观察到了大约 0.02 天的稳定准周期振荡。在 JD 2458575 (2019) 的夜晚，在 3 分钟内观察到亮度增加了 0 m .7，然后是指数衰减。耀斑在前半段持续了大约一个小时，其中观察到周期约为 0.006 天、振幅为 0 m .1 的振荡，这可能与白矮星的自转周期或准周期振荡有关。耀斑的性质尚不清楚，本文研究了这种效应的可能原因。