We return to an old friend of the project this week. The young star V1490Cyg in the Pelican Nebula. The star has been the subject of one of our first papers, and we subsequently looked at its light curve again in week 178.
The star showed periodic dimming events roughly once a month. While the depths of the events and their duration kept changing, and some events did not happen at all at a detectable level, the period remained the same.
In the above image we show the V and I-Band data for the object in 2023. There are still dimming events. Some are deeper than others, and some are barely detectable. However, somethings has changed. The gap between successive events is no longer ~31days. Some gaps appear to be about 20 days, others even slightly shorter.
In the 2024 light curve (not shown) these changes continue and there we can find occasions with 10day gaps between dimming events and a generally much more chaotic light curve. If these events are indeed caused by material in the inner disk (which is warped), then something has change the orbital separation of the warp from the star, and thus the period.
We will keep a close eye on this one and see what happens this summer. Please keep observing this field (and of course all the others) so can see what is happening and understand the causes.