CV Alerts from Outbursts Alerting System #2
Andrii Simon
Dear BHTOM community,
1. Gaia22dbc — end of superoutburst
First of all, we would like to thank you for your observations of Gaia22dbc (18:29:28.080 +28:28:36.732). The object is now fading, and the current superoutburst will soon come to an end. We would greatly appreciate it if you could keep this object on your observing list for continued monitoring over the next few weeks or even months, with observations once or twice per night. These data will be very useful for further analysis of the object's activity.
2. Gaia16amd — current superoutburst
Gaia16amd (20:35:29.772 +06:36:52.740) is currently undergoing a superoutburst, which may continue for approximately another week.
For this object, we are particularly interested in long time-series observations of 4–5 hours in a single filter (R, r, or clear) to study the evolution of the superhumps. Alternatively, separate BVRI measurements obtained periodically throughout the night would also be very useful.
3. Gaia19bnd — expected superoutburst around 19–21 September
The next superoutburst of Gaia19bnd (22:25:48.024 +25:25:10.812) is expected to begin around 19–21 September 2026. Since the exact onset cannot be predicted, continuous monitoring before and during the expected event is especially important.
We kindly ask you to:
3a) obtain separate BVRI measurements periodically throughout the night from now until the end of the superoutburst. If observations in all four filters are not possible, observations in any single filter would also be useful;
3b) starting from 15 September, obtain long time-series observations in a single filter (R, r, or clear), whenever possible, in order to catch the onset of the superoutburst and follow the evolution of the superhumps, if they develop.
4. Gaia22cax — superoutburst expected in late August or September
The most important, but also the most challenging, target is Gaia22cax (00:01:30.456 +05:06:23.400). We expect its next superoutburst sometime in late August or September 2026, but unfortunately we have no more precise prediction for its onset.
We therefore kindly ask you to:
4a) obtain separate BVRI measurements periodically throughout the night from now until the end of the superoutburst. If observations in all four filters are not possible, observations in any single filter would also be useful;
4b) once we detect the onset of the superoutburst, we will inform you by email and ask you to obtain long time-series observations in a single filter (R, r, or clear), in order to catch the early stages of the superoutburst and follow the evolution of the superhumps, if they develop.
Your observations are extremely valuable for understanding the outburst behaviour and superhump evolution of these systems. Thank you very much for your continued contributions to the BHTom observing campaign.
With kind regards,
Andrii Simon
on behalf of the Outbursts Alerting System
