This week we look at the R and B-Band light curve of the young star AHOri, situated just North of the Orion nebula.
We have looked at the long term behaviour of the object in week 173. It was showing some several year long variations of about 0.5 to 1.0 magnitude. In addition there were short term (few days to weeks) magnitude changes of up to 1.5 magnitudes, which were stronger or weaker over time. We had another look at the 2022/23 light curve of the star in week 232. We noticed that is was showing its usual behaviour, but ~50d before the end of the observing season there was a clear change. It suddenly dimmed by about a magnitude and displayed much more strong and shorter term variations than before.
So what has happend to the object in the 2023/24 observing season? That is shown in the image above. There are less data points, but the more erratic behaviour has remained. The overall brightness of the system is unchanged on average. About 70d before the end, the brightness in the red filter suddenly jumped by about 1mag, while all others (we have I and V-band data not shown) remain the same. This could be due to some changes in the accretion rate (the R-band contains the Halpha emission line) or changes in the brightness of the background nebulosity, influencing the photometry. Certainly an interesting source to keep an eye on and to investigate in more detail.