The Occultation by Bertha

Sun eve Oct 22, 2017

This fairly high rank event is at a convenient time, but a difficult altitude of only 10 degrees in the northeast, in southern Aries. The site that has the best odds and not too far away, is on Calaveras Rd, a turn out soon after crossing over the ridge, at 37d 26.88' latitude, elevation 1,000 ft.



I changed my plans to get to a gap in the coverage, driving up Hwy 1 instead. I got to my new planned site, at the road on the ridge above the Montara Hostel, and found that cypress trees blocked the 10 degree eastern horizon a total no-go! Drove back south a mile and thought I'd try heading towards the cliff-top "The Distillery", where I'd treated my friends to a very nice dinner before a trip to the SF Symphony many years ago. Took a turn and found a terrific eastern horizon as I paralleled the Half Moon Bay airport, and set up there. Skies were clean and perfect, and I was able to get on the target with the LCD even when the star was only about 5 degrees above the horizon. Made positive ID easily, and got a good video recording considering the rapid scintillation. I was amazed and disappointed to see that despite the 92% odds of a "hit", it looked like a miss. Now, it's the next night and I'm running it through LiMovie. Used 5/7/15 circles for photometry to avoid overlapping on the close companion, which was the comparison star. Circles tracked well but only after I re-started at 2:37:49, after the final re-centeringt adjustment. I actually took 2 more minutes of video data than is shown on the images below.

Now, the photometry looks a little more interesting. The deepest drop is to ~zero level for just one integration (which was on 4x or 2-frame integration, but Messner's miss was north of me, so I definitely had a miss (and a useless one at that!)

70 seconds of data after the final re-centering. I have 2 additional minutes not included here. The deepest drop is at the predicted time of the event, but only for a single integrated frame point. However, it now turns out there was Messner's miss north of mine, so I definitely had a miss.

Close up


Here's the skyplot of all observers