[vsnet-alert 22842] Re: ASASSN-18aan: stage A-B transition?

[Yasuyuki WAKAMATSU]

Kyoto U. team, Tonny Vanmunster, Osaka Kyoiku U. team and
Mizutani-san reported further observations.

The stage A-B transition seems to have occurred on December 8. The
object shows stage B superhumps now. After the object reached the
brightest state on December 9, it gradually continues to fade. By
analogy with ASASSN-18yi, the object is thought to enter the fading
period in several days or a week.


(2018/12/12 13:39), Yasuyuki WAKAMATSU wrote:
> 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
>


-- 
若松恭行
京都大学大学院理学研究科宇宙物理学教室
E-Mail:wakamatsu at kusastro.kyoto-u.ac.jp