Apologies for missing to post this last week. On the plus side, we will have two light curve of the week post this week 🙂
We have another look at an old friend of the project, the variable star V350Cep in the NGC7129 cluster. We last looked at it back in March during the observing gap, when it is least visible. We had seen that this object, which has been in a bright state after an eruption in the early 70s (i.e. for about 50yr now) had shown a longer lasting dimming event.
The new observing season for the object is now a few months old, and we have about 120d worth of new data, which are shown in the above plot (the second group of points). We can see that source is still faint, and has now dropped to about 17.8mag in the V-Band. This is hence now more or less one year since the start of the dimming event(s). This is quite unusual for this source, which has only shown very few dimming events since its original brightening, and all of them lasted at most a few months.
The brightness is still varying significantly at this lower level, so the drop in brightness could be due to outer disk material blocking the direct line of sight to the central star. However, an alternative might be that the eruption is finally coming to an end. If the star was to reach it’s pre-burst state, the brightness should drop another 2.5mag at least. We will see what happens over the next months/years. There has been so far no really good example of a star with such a major, long-term eruption, where the decline to pre-burst brightness has been observed. Hence, we do not know how this happens, and how long it takes …. we might find out (or not 😉 ).