2014B Day 5: Corrected Dispersion

The big story over the last 30 hours has been our atmospheric dispersion corrector, or ADC. When you look at a star through the atmosphere, it will be “dispersed” into a rainbow, meaning that the different wavelengths of light (colors) will land at different spots on the camera. But if you have an ADC, it takes out this dispersion. The ADC is two prisms which have to be rotated in opposite directions in a fairly precise way. Well, ours stopped being precise, or maybe it was just random. Opinions vary. We spent the last half of last night taking pieces of it apart and testing various theories. We didn’t get anywhere, but after a long-day’s sleep, Laird had a plan. To keep a long story from getting longer, one of the two rotating prisms tends to get jammed up in one part of its range of motion. We now have a workaround in place for this, with a bunch of software hacks to enforce some new rules. So, problem solved! Just like that.

That image makes me pretty happy. See how the lines (they’re speckles in a very broad pass band) running out from the star are all straight? That means we have the ADC working.

To put that in perspective, when I went to bed yesterday morning I was pretty sure we had to pull MagAO off the telescope and tear apart the ADC. It’s good to be wrong about some things.

Losing some time to the ADC troubleshooting hasn’t been too hard to take, because we’ve had some cloudy nights.

The Babcock Lodge with some clouds
Magellan with clouds. This is a rare sight as far as the MagAO team is concerned.

Here are some more pictures of the mounting and cabling from yesterday.

Laird and Katie hooking up Clio
Here’s Laird and me connecting all the cables that let us talk to the system.

MagAO’s favorite Chef is on this week. Here’s an example of why we love Hector so much.

This was dessert at Lunch! You should stop by for dinner some time.

I found some more flowers today.

Some more flowers.

Clouds suck. They should never come near any observatory where I have time. But, they make for nice pictures.

Tonight’s sunset. Click for panorawesome.
The MagAO team shows off some of our swag. Note that I’m not looking at the camera, I got distracted by the loop “pausing” and was making sure it came back ok.

There’s a lot of pressure for us instrumenteers in the days before a run, especially such a long one. We have many people coming to visit us and use MagAO, and we need to have the system in top form when they get here. I think we did it — MagAO is ready to go. But, needless to say, we worked pretty damn hard the last couple of days.