Dip update 53/n
[Orig: Aug 9, 2017]
Two graphs to share on the data from last night. The first is the nightly averages, the overall brightness is still down (I have removed the two recent TFN points that had large errors due to poor transparency):
But something very interesting happened in the early part of last night, as you can see below in the hourly averages for the past couple days (the color of the data points are the same as above for TFN and OGG):
At the time TFN started taking observations (blue points), the flux was way down(!!); and it continued to change quite significantly over the course of a couple hours. At the end of the TFN visibility window, it had returned to the same level of brightness from the previous day, and this continued for the time it was observed at OGG. This short term variability was also independently detected by colleagues observing at the TJO telescope in Spain, so the chances are very good that it is real (not a problem with the data). Unfortunately what we saw didn't last long, only a couple of hours. But we don't have any coverage just before it, from 94.1-94.3 on this x-axis, so we could only guess to what happened during that time: did we catch it on the way up from a quick, big drop, or was the event more shallow and gradual?
I have been reminded that its probably a good idea to note that the data shown here are normalized to unity. Normalizing to unity shows the depths of the dips plus any long term dimming trends that may be occurring, which is what we care about anyway (the total amount of stuff is between us and the star). We will need a lot more data (when the star is not dipping) to address this long term dimming properly, and at this point its best to avoid such speculation.
~Tabby and team