This weeks light curve does not look very interesting. But it is 🙂
We show the R and I-band data for the last two years for the star Cl* IC 348 LRL 237. It is situated in the IC348 target region in Perseus, and is thus part of one of the closest targets with an estimated distance of about 318pc. We see that the object is quite faint, there are some outlier data points which need to be removed, and there is possibly a small long term dimming trend over the two years. However, the roughly 0.2mag dimming is smaller than the typical photometry errors.
So why is it interesting? Well, given the distance, age and extinction of the cluster, as well as the spectral type of the object (M5V), it is most likely a (young) Brown Dwarf, rather than a (young) star. In other words it at the borderline of about 80 Jupiter masses, where it potentially never gets hot and dense enough in the core to ignite the stable fusion of normal Hydrogen atoms (the Deuterium is/will fuse).
Thus, this is one of the very few light curves of brown dwarfs we have in our data that has a reasonable amount of detections. One can see that in the R-band the object reaches almost 19th magnitude, and it is even fainter in the shorter wavelength filters (e.g. B=21.5mag) so it is not detected in most of the images. Most other Brown Dwarfs in our target regions are much fainter than this due to lower masses and larger distances.