Well, another expedition, to another place, chasing yet another elusive occultation, is always interesting and fun!
I was recently invited to participate in a NSF-funded expedition to observe an occultation of Triton, one of Neptune's thirteen moons.
Occultations occur when an object passes in front of an other object, in this case a moon passing in front of a star. This time, instead of far off South Africa, the occultation was visible from rural North Florida and South Georgia. And, this time, I was able to use Paramount mounts. (Yes, the plural is not an typo; Software Bisque lent four mounts to the expedition!)
I flew into Jacksonville Florida, a day after everyone else as I was returning from the Advanced Imaging Conference (AIC), and arrived to find the rest of the team, and all twenty-three of my boxes safe and sound. After dividing the equipment into four separate systems, we set them up, along with the other systems from the expedition, in a vacant parking lot. (Not that it was a race, but the Paramount systems were the first to finish setting up; even the one being assembled by the team members who had never done so before).
The next day offered time to go out and scout. Just like in South Africa, we had to observe from a specific latitude. We followed the latitude line into the countryside in search of open areas with amendable owners who might let us use their property. The event's timing was less than ideal, as the occultation occurred only 45 minutes after sunset and at only about 20 degrees altitude. This was not going to be easy, and as a matter of fact, it really was a race, not against each other, but against the sun.
My team headed west, and while we initially struck out, found a great dark site, where no one cared that we were there. A graveyard. Well, actually the Riverside Cemetery, but graveyard sounds better, especially in late October.
We setup there two nights before the event and had great success. We were able to get on field easily and quickly and got our test data. But then, as always there was a wrinkle in our plans. The weather reports came in. We talked to the National Weather Service and they predicted our site would be overcast at event time. After learning this news, we again packed up and headed further west, only hours before the event. This was more than just an inconvenience as every kilometer we drove west meant less time between sunset and event time.
We eventually found a new site next to a small gravel road on a farm in Greenville.
We setup with very little time to spare, and, while the weather was a bit dicey, we were still able to image the occultation!
Elsewhere, the other Paramounts were doing their job with other teams. After all was said and done, the entire expedition was quite successful. Once the event was over, "all" that was left to do was pack everything back into a 15-foot cargo van...which barely fit, and fly home.
At this point you might be asking, "What was the point of all this?" Fair question. Unlike the occultation in South Africa, this one was not about nailing down the orbital parameters
of a distant object, as Triton's are already well-known (or should be; there was a moderately
large systematic error in the JPL-supplied Triton coordinates, which meant the center of the occultation
as viewed from Earth was much further south than predicted. But further south was cloudy, and we got the best data we could have anyway).
This time, the goal was to about learn about Triton and its atmosphere.
10-31-2017 2:53 PM