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XZ Eri: unusual eclipse timing behavior! Dear Collagues, We have received new complete data sets from Berto Monard (5 nights in total), one night from Lew Cook, and one night from Kiyota-san. The regular analysis of the Kyoto, Torii-san (RIKEN), Tanabe-san (VSNET Okayama Station), Okayam U. of Sci. team observations is steadily in progress. The amplitude of the superhumps has become slightly reduced, but the overall feature (hump profile and the beat phenomenon) is persistently seen. There is also emerging evidence of the secondary superhumps (secondary peaks on the decline branch). The object is expected to brighten, likely accompanied with a regrowth of superhumps, during this week. Further intensive coverage is highly encouraged. We have been able to more precisely determine the eclipse timings with the newly available data. Astonishingly, large negative eclipse O-C's were suddenly recorded on a single night on Jan. 29. Otherwise the O-C change has been smooth and has not show such a large deviation. The initially reported O-C changes, which were initially regarded as "beat phenomenon", are not a periodic phenomenon, but a strikingly transient phenomenon! Since mutiple observers obtained high-quality data on that night, the phenomenon was most likely real. For the first three nights, the O-C showed a gradual decrease (except on Jan. 29), The O-C variation somewhat resembles that of HT Cas during the 1995 November outburst (normal outburst) (cf. Ioannou et al. 1999, MNRAS 310, 398). There must have been a very strong source of asymmetry on the accretion disk. We are going to further analyze the data to solve this mystery. Updated eclipse predictions are attached: Regards, Taichi Kato VSNET Collaboration team === Eclipse predictions (UT, geocentric) 20030204 00:32:48 20030204 02:00:53 20030204 03:28:58 20030204 04:57:03 20030204 06:25:08 20030204 07:53:13 20030204 09:21:18 20030204 10:49:23 20030204 12:17:28 20030204 13:45:33 20030204 15:13:38 20030204 16:41:43 20030204 18:09:48 20030204 19:37:53 20030204 21:05:58 20030204 22:34:03 20030205 00:02:08 20030205 01:30:13 20030205 02:58:18 20030205 04:26:23 20030205 05:54:28 20030205 07:22:33 20030205 08:50:38 20030205 10:18:43 20030205 11:46:48 20030205 13:14:53 20030205 14:42:59 20030205 16:11:04 20030205 17:39:09 20030205 19:07:14 20030205 20:35:19 20030205 22:03:24 20030205 23:31:29 20030206 00:59:34 20030206 02:27:39 20030206 03:55:44 20030206 05:23:49 20030206 06:51:54 20030206 08:19:59 20030206 09:48:04 20030206 11:16:09 20030206 12:44:14 20030206 14:12:19 20030206 15:40:24 20030206 17:08:29 20030206 18:36:34 20030206 20:04:39 20030206 21:32:44 20030206 23:00:49 20030207 00:28:54 20030207 01:56:59 20030207 03:25:04 20030207 04:53:09 20030207 06:21:14 20030207 07:49:19 20030207 09:17:24 20030207 10:45:30 20030207 12:13:35 20030207 13:41:40 20030207 15:09:45 20030207 16:37:50 20030207 18:05:55 20030207 19:34:00 20030207 21:02:05 20030207 22:30:10 20030207 23:58:15 20030208 01:26:20 20030208 02:54:25 20030208 04:22:30 20030208 05:50:35 20030208 07:18:40 20030208 08:46:45 20030208 10:14:50 20030208 11:42:55 20030208 13:11:00 20030208 14:39:05 20030208 16:07:10 20030208 17:35:15 20030208 19:03:20 20030208 20:31:25 20030208 21:59:30 20030208 23:27:35 20030209 00:55:40 20030209 02:23:45 20030209 03:51:50 20030209 05:19:56 20030209 06:48:01 20030209 08:16:06 20030209 09:44:11 20030209 11:12:16 20030209 12:40:21 20030209 14:08:26 20030209 15:36:31 20030209 17:04:36 20030209 18:32:41 20030209 20:00:46 20030209 21:28:51 20030209 22:56:56 20030210 00:25:01 20030210 01:53:06 20030210 03:21:11 20030210 04:49:16 20030210 06:17:21 20030210 07:45:26 20030210 09:13:31 20030210 10:41:36 20030210 12:09:41 20030210 13:37:46 20030210 15:05:51 20030210 16:33:56 20030210 18:02:01 20030210 19:30:06 20030210 20:58:12 20030210 22:26:17 20030210 23:54:22 20030211 01:22:27 20030211 02:50:32 20030211 04:18:37 20030211 05:46:42 20030211 07:14:47 20030211 08:42:52 20030211 10:10:57 20030211 11:39:02 20030211 13:07:07 20030211 14:35:12 20030211 16:03:17 20030211 17:31:22 20030211 18:59:27 20030211 20:27:32 20030211 21:55:37 20030211 23:23:42 20030212 00:51:47 20030212 02:19:52 20030212 03:47:57 20030212 05:16:02 20030212 06:44:07 20030212 08:12:12 20030212 09:40:17 20030212 11:08:23 20030212 12:36:28 20030212 14:04:33 20030212 15:32:38 20030212 17:00:43 20030212 18:28:48 20030212 19:56:53 20030212 21:24:58 20030212 22:53:03
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