This week we have a timely look at a newly identified Gaia variable named Gaia24avc. It is situated in the Elephant Trunk Nebula region. It was identified 11 days ago. However looking at the Gaia light curve, one can see that it has had short dimming events in the past. The object is a known Herbig Ae/Be star. This means that it is a more massive young stellar object.

In the light curve above, we show the B, V, R, and I data from HOYS for the object over the last year or so. Note that the magnitudes in the different filters have been slightly shifted to make the plot look better. We can see that the object had a general, steady, linear brightness decline for about 4 months, followed by a short recovery and the a decline again. The end of the data we have is rather sparse, due to the object not being easily observable in the winter.

Overlaid on these longer term trend are short term variations on timescales of weeks. As mentioned before, statistically, the timescale of the variations is related to the size and/or the orbital radius of the structures in the disk that occult the star and cause the variations. I.e. faster moving material closer to the star will cause faster changes in brightness, usually also lasting less time.