This weeks feature light curve is another of the objects that have been flagged up as variables by the Gaia satellite. We are looking at the object Gaia22agc, which was announced yesterday. The object is a know variable star (V718Per) and young stellar object. It is situated in the IC348 Cluster target region of HOYS.
We show the V, R and I data of HOYS for the target star. The light curve from Gaia and ours show a very pronounced long term variability. Both data sets show minima in brightness about five years apart. In between the object has brightened by about one magnitude, and it is now again in the bright state. To see if this is indeed a periodic pattern we checked the AAVSO light curve, but there is no data available prior to the start of our light curve. Thus, we will have to keep observing this field for a few more years to see if this is indeed periodic.
Besides the long term variations there seem to be only minor short term changes in the brightness. The scatter from the long term trend does increase in the last few years, but this is most likely due to uncertainties in the photometry , and colour terms (note they are not corrected in this plot). We will have to ‘clean’ the light curve from uncertain measurements before a more detailed analysis. This is in particular important for this source, as is is situated near/in an extended nebulosity and has another equal brightness star very close by. Both of these can cause uncertainties in the automatic photometry of objects.