Last week’s post was about the erupting Be-type star Gaia19eyy. As discussed, we published our detailed analysis of this object in the fifth paper in our series, entitled: “A survey for variable young stars with small telescopes: VI – Analysis of the outbursting Be stars NSW284, Gaia19eyy, and VES263“. This paper was originally about the first object in the title – NSW284. We discovered this source very early on during our project, probably around 2016. However, it took us a long time to figure out what this star really is.
Until last week, this source had not been flagged as a Gaia alert, despite it’s highly variable nature. This was due to how the detection algorithm works, i.e. it only flags up newly variable stars (see here for the full details) and this object was varying right from the start of the observations with Gaia. Now finally, on December 6th, the object has been identified as Gaia23dmc. Looking at the light curve, one can see it behaves very similar to the other repeating Be-star burster. It seems to have been flagged up this time, as the latest burst has been slightly higher than the previous ones.
In the figure above we show the HOYS data for this object during this summer. It covers the low state in the first half of the year, including a slight, failed (?) burst, and the increase to the current peak brightness. As you can see, we do not have a very good coverage for this field this summer. This is partly due to some observatories being no-functional, and the fact that it is usually just outside the field of view of most of the cameras used by our participants if pointed at the nominal field centre for this target (IC1396A).
The continued high cadence monitoring of these bursts, especially in colour is important for finding out (eventually) what exactly causes these bursts – something we still do not know. So, as ever, please keep an eye on this field when you can – and of course also all the other fields 😉