This week we stay again in the Pelican Nebula (there are a lot of interesting objects here 🙂 ), and look at the object 2MASS J20522802+4403311. It is classified as an Orion Variable in SIMBAD, and as you can see in the above V, R, I-Band HOYS light curve, this is justified. The star shows multiple deep dimming events. The current maximum change in the V-band brightness that we have observed is about 2.5 mag. This means at its faintest only 10% of the flux is detectable compared to the maximum.

In addition to the deep dimming events, the star also varies on very short timescales by about half a magnitude. The colour changes in the deeper dimming events are nicely corelated, hinting that they are caused by extinction events from disk material. On the other hand, during the short term variations the colours are not nicely corelated. This is in part due to the photometric uncertainties in the data, but is also a hint that the physical reasons for these variations are a combination of causes, i.e. changes in extinction, accretion rate, and potentially spots. Plenty to study in detail 🙂 .