[vsnet-alert 22825] ASASSN-18aan: stage A-B transition?

[Yasuyuki WAKAMATSU]

ASASSN-18aan: stage A-B transition?

Itoh-san, Tamas Tordai and Osaka Kyoiku U. team reported
further observations.

The O-C diagram indicates the object showed the stage A-B transition
on December 10. The period of stage A superhumps is 0.16229(6) d.
The mass ratio estimated from the refined orbital period of 0.14941(1) d
and the period of stage A superhumps is 0.265(2).

Further time-resolved observations, if possible, multi-color observations
are encouraged.

The updated ephemeris of eclipses calculated from the epoch of
2018-12-11 00:25:28 (UTC) and the orbital period are as follows:

2018-12-12 05:06:44
2018-12-12 08:41:53
2018-12-12 12:17:03
2018-12-12 15:52:12
2018-12-12 19:27:22
2018-12-12 23:02:32

2018-12-13 02:37:41
2018-12-13 06:12:51
2018-12-13 09:48:00
2018-12-13 13:23:10
2018-12-13 16:58:19
2018-12-13 20:33:29

2018-12-14 00:08:38
2018-12-14 03:43:48
2018-12-14 07:18:57
2018-12-14 10:54:07
2018-12-14 14:29:16
2018-12-14 18:04:26
2018-12-14 21:39:35

2018-12-15 01:14:45
2018-12-15 04:49:54
2018-12-15 08:25:04
2018-12-15 12:00:14
2018-12-15 15:35:23
2018-12-15 19:10:33
2018-12-15 22:45:42

2018-12-16 02:20:52
2018-12-16 05:56:01
2018-12-16 09:31:11
2018-12-16 13:06:21
2018-12-16 16:41:30
2018-12-16 20:16:40
2018-12-16 23:51:49

2018-12-17 03:26:59
2018-12-17 07:02:08
2018-12-17 10:37:18
2018-12-17 14:12:28
2018-12-17 17:47:37
2018-12-17 21:22:47

2018-12-18 00:57:56
2018-12-18 04:33:06
2018-12-18 08:08:15
2018-12-18 11:43:25
2018-12-18 15:18:35
2018-12-18 18:53:44
2018-12-18 22:28:54

2018-12-19 02:04:03
2018-12-19 05:39:13
2018-12-19 09:14:23
2018-12-19 12:49:32
2018-12-19 16:24:42
2018-12-19 19:59:51
2018-12-19 23:35:01

2018-12-20 03:10:11
2018-12-20 06:45:20
2018-12-20 10:20:30
2018-12-20 13:55:39
2018-12-20 17:30:49
2018-12-20 21:05:59