Light curve (click to enlarge):
"Pi of the Sky" automatic trigger has detected a new object on the sky at (2000) RA = 02 32 38, DEC = -37 17 43. No known variable star or minor planet is present at this position.
Possible identification (thanks to Sebastian Otero):
1RXS J023238.8-371812 = VSX J023237.9-371755 = GSC2.3 S359006775 = GSC2.2 S03332316775 = USNO-B1.0 0527-0033740
Response from Taichi Kato, VSNET (to our mail)
Although I don't have sufficient information, there seems to be a good candidate for the optical counterpart of this RXS source. According to 6dF catalog, the object g0232379-371755 (02 32 37.91, -37 17 55.3) is located close to the RXS position and has a redshift of zero (Galactic object). The object is in GSC 2.2 with Bj=18.24 and R=18.15 (blue!). All the data suggest that this object can be a cataclysmic variable presently undergoing an outburst. The (supposed) large outburst amplitude would suggest an SU UMa-type or a WZ Sge-type outburst. Accurate astrometry of the outbursting object and urgent time-series photometry is very strongly encouraged!
Followup "KANATA" team results: astrometry, spectrum, V-J
AAVSO Special Notice #72: 1RXS_J023238.8-371812 rapid fading
"Pi of the Sky" images 60x60 arcmin (click at the picture to enlarge):
Light curve (click to enlarge):
| HJD | Date UT | Time UT | UT-decimal | magnitude |
| 2454356.628 | 2007-09-13 | 03:00:27 | 20070913.12531 | > 13.01 |
| 2454357.875 | 2007-09-14 | 03:00:46 | 20070914.12553 | > 12.83 |
| 2454358.870 | 2007-09-15 | 08:28:34 | 20070915.35317 | > 12.81 |
| 2454359.874 | 2007-09-16 | 08:53:44 | 20070916.37065 | 10.53 |
| 2454361.878 | 2007-09-18 | 08:59:51 | 20070918.37490 | 10.94 |
| 2454362.870 | 2007-09-19 | 08:48:22 | 20070919.36692 | 11.03 |
| 2454363.874 | 2007-09-20 | 08:53:51 | 20070920.37073 | 11.26 |
| 2454364.872 | 2007-09-21 | 08:50:16 | 20070921.36824 | 11.22 |
| 2454366.873 | 2007-09-23 | 08:53:01 | 20070923.37015 | 11.59 |
| 2454367.873 | 2007-09-24 | 08:52:18 | 20070924.36965 | 11.51 |
| 2454368.879 | 2007-09-25 | 09:01:19 | 20070925.37591 | 10.73 |
| 2454370.7159 | 2007-09-27 | 05:05:35 | 20070927.21221 | 11.55 |
| 2454370.7724 | 2007-09-27 | 06:27:02 | 20070927.26877 | 11.64 |
| 2454371.6934 | 2007-09-28 | 04:33:18 | 20070928.18979 | 11.91 |
| 2454371.7053 | 2007-09-28 | 04:50:18 | 20070928.20159 | 11.90 |
| 2454371.7289 | 2007-09-28 | 05:24:19 | 20070928.22521 | 11.87 |
| 2454371.7486 | 2007-09-28 | 05:52:45 | 20070928.24496 | 11.88 |
| 2454371.7753 | 2007-09-28 | 06:31:06 | 20070928.27159 | 11.80 |
| 2454372.7015 | 2007-09-29 | 04:44:52 | 20070929.19782 | 11.93 |
| 2454372.7186 | 2007-09-29 | 05:09:32 | 20070929.21495 | 11.93 |
| 2454372.7312 | 2007-09-29 | 05:27:35 | 20070929.22748 | 11.97 |
| 2454372.7469 | 2007-09-29 | 05:50:13 | 20070929.24320 | 11.91 |
| 2454372.7595 | 2007-09-29 | 06:08:21 | 20070929.25579 | 11.93 |
| 2454372.7721 | 2007-09-29 | 06:26:28 | 20070929.26837 | 11.92 |
| 2454375.6937 | 2007-10-02 | 04:33:34 | 20071002.18997 | 11.91 |
| 2454375.7055 | 2007-10-02 | 04:50:34 | 20071002.20178 | 11.90 |
| 2454375.7278 | 2007-10-02 | 05:22:42 | 20071002.22409 | 11.93 |
| 2454375.7396 | 2007-10-02 | 05:39:38 | 20071002.23585 | 12.02 |
| 2454375.7514 | 2007-10-02 | 05:56:39 | 20071002.24767 | 11.94 |
| 2454375.7632 | 2007-10-02 | 06:13:39 | 20071002.25947 | 11.94 |
| 2454375.7750 | 2007-10-02 | 06:30:40 | 20071002.27129 | 11.92 |
| 2454376.6939 | 2007-10-03 | 04:33:50 | 20071003.19016 | 11.75 |
| 2454376.7065 | 2007-10-03 | 04:52:00 | 20071003.20277 | 11.81 |
| 2454376.7303 | 2007-10-03 | 05:26:20 | 20071003.22662 | 11.69 |
| 2454377.6935 | 2007-10-04 | 04:33:13 | 20071004.18973 | 11.83 |
| 2454377.7060 | 2007-10-04 | 04:51:20 | 20071004.20231 | 11.89 |
| 2454377.7219 | 2007-10-04 | 05:14:12 | 20071004.21819 | 11.99 |
| 2454377.7345 | 2007-10-04 | 05:32:20 | 20071004.23078 | 11.99 |
| 2454377.7471 | 2007-10-04 | 05:50:27 | 20071004.24336 | 11.94 |
| 2454377.7596 | 2007-10-04 | 06:08:30 | 20071004.25590 | 11.89 |
| 2454377.7722 | 2007-10-04 | 06:26:37 | 20071004.26848 | 11.88 |
| 2454378.694 | 2007-10-05 | 04:33:33 | 20071005.18996 | 11.87 |
| 2454378.706 | 2007-10-05 | 04:51:41 | 20071005.20255 | 11.87 |
| 2454378.719 | 2007-10-05 | 05:09:48 | 20071005.21513 | 11.89 |
| 2454378.731 | 2007-10-05 | 05:27:51 | 20071005.22767 | 11.86 |
| 2454378.744 | 2007-10-05 | 05:45:58 | 20071005.24025 | 11.83 |
| 2454378.757 | 2007-10-05 | 06:04:06 | 20071005.25284 | 11.83 |
| 2454378.769 | 2007-10-05 | 06:22:13 | 20071005.26542 | 11.84 |
| 2454378.782 | 2007-10-05 | 06:40:20 | 20071005.27800 | 11.91 |
| 2454379.694 | 2007-10-06 | 04:33:24 | 20071006.18986 | 12.12 |
| 2454379.712 | 2007-10-06 | 04:59:39 | 20071006.20809 | 12.03 |
| 2454379.733 | 2007-10-06 | 05:30:04 | 20071006.22921 | 11.94 |
| 2454379.746 | 2007-10-06 | 05:48:12 | 20071006.24180 | 11.87 |
| 2454379.758 | 2007-10-06 | 06:06:15 | 20071006.25434 | 11.94 |
| 2454379.780 | 2007-10-06 | 06:37:59 | 20071006.27637 | 12.01 |
| 2454380.694 | 2007-10-07 | 04:33:19 | 20071007.18980 | 12.04 |
| 2454380.708 | 2007-10-07 | 04:54:34 | 20071007.20456 | 11.94 |
| 2454380.720 | 2007-10-07 | 05:11:34 | 20071007.21636 | 11.93 |
| 2454380.730 | 2007-10-07 | 05:26:23 | 20071007.22665 | 11.92 |
| 2454380.742 | 2007-10-07 | 05:43:24 | 20071007.23847 | 11.90 |
| 2454380.754 | 2007-10-07 | 06:00:24 | 20071007.25027 | 11.94 |
| 2454380.766 | 2007-10-07 | 06:17:24 | 20071007.26208 | 12.00 |
| 2454380.783 | 2007-10-07 | 06:41:37 | 20071007.27890 | 11.95 |
| 2454381.700 | 2007-10-08 | 04:42:46 | 20071008.19636 | 12.29 |
| 2454381.713 | 2007-10-08 | 05:00:54 | 20071008.20896 | 12.29 |
| 2454381.725 | 2007-10-08 | 05:18:56 | 20071008.22148 | 12.23 |
| 2454381.738 | 2007-10-08 | 05:37:04 | 20071008.23407 | 12.27 |
| 2454381.750 | 2007-10-08 | 05:55:11 | 20071008.24665 | 12.27 |
| 2454381.763 | 2007-10-08 | 06:13:19 | 20071008.25925 | 12.34 |