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MAPS Jun. 2025A Night 4: RM modes

Tonight was another beautiful clear night. Seeing ranged from around 1-3 arcseconds. At the start of the night we were confused why we were seeing very little AO correction — it turns out the TT mirror was not modulating, oops! After this we took several sets of AO-on vs. AO-off Pisces data. We also compared the response matrix modes for a set of 20-modes-RM taken with 5 trials and it is encouraging that we are seeing the Zernike-ish modes as expected!

The song of the night is “Num Num Cat TikTok Chain but its actually good lol”:

MAPS Jun. 2025A Night 3: IR CACAO

The return of IR WFSing! After squashing some software bugs we closed the loop on 3 and then 20 modes with CACAO using the IR WFS:

I’m back at home where I’m finding it brilliant, reliable, intelligent, diligent, glorious, exceptional, and troublesome. Thanks to the mountain team for enabling a good remote-observing session.

The song of the night is Malagueña – Michael Lucarelli, classical guitar:

MAPS Jun. 2025A Night 2: Aligning CACAO

Tonight after some daytime work on the rotator we tried the rotational centering again. Alas Brian saw that the star was still jumping when he sent the command, and thus we still couldn’t find the chief ray. We moved on and attempted a curvature wavefront sensing test where we defocussed the hexapod and that helped us get as close as we could get with alignment.

From last night’s opening:

Next up was CACAO to start improving our AO modes. This took us a while to get set up, especially the IR WFS which we haven’t used for almost a year. By the end of the night we had a 3 modes loop and were attempting to move on but needed more help with the gains gui that was again not working. Tomorrow we’ll keep going!

Here is the MLAT with the IR WFS:

The song of the night is “Diggy Diggy Hole” by Wind Rose:

MAPS Jun. 2025A Night 1: Rotational centering

Hello dear blog friends, I’m back after being away due to beautiful, robust, inquisitive, dynamic, gregarious, exuberant, thoughtful reasons. And here we are at the MMT to observe adaptive-optically again!

The installation was more challenging than usual because both MMTO and MAPS teams were somewhat short staffed, but was still all done well by sunset.

As per usual we started with alignment. Once we got the star on Pisces (with, again, disturbingly unique-to-this-run Az-El offsets), we did a rotational centering test in order to find the chief ray. Not the one where you rotate your images and see where the star goes on the pixels, but the one where you rotate the instrument and see where the star goes on the camera. We started the rotator at -60 and went all the way to +60 — the result was a compact bean (looks kinda like this). We started the rotator at +60 and went all the way to -60 — the result was a large arc (looks kinda like this). (Images taken in strip scan mode.) The center of the bean did not coincide with the center of the arc. The arc did not overlap the bean. We saw the same behavior on the acquisition camera, so it’s not the Pisces mount wobbling. It seems the rotator itself is jumping at the start of a move. And it appeared to be when started from any initial position.

With that diagnosed and the star set to somewhat the average center, we decided to stop messing with the instrument rotator (which we don’t generally move as of yet) and moved on to WFS alignment. This included working on the fibers for the newly re-installed IR WFS, adjusting the tip/tilt mirror settings and checking whether differences between Vis and IR were due to any common optics, and finally closing up at dawn with still an open question about co-alignment. To be continued tomorrow night!

The song of the night is “The Happy Song” by Imogen Heap:

GMagAO-X featured in Steward GMT overview

We haven’t said much about GMagAO-X since the PDR went well, but we’re still a key part of the collaboration’s suite of instruments. This week we’re in the Steward news talking about what the future instrument could mean for science:

At first light, astronomers will use a special tool called GMag AO-X, an “extreme AO” coronagraph. It will block out starlight and reveal the faint glimmers of orbiting planets.

“The Giant Magellan Telescope will be a major upgrade for our ability to study planets around other stars, especially when we take pictures of them using the in-development instrument GMag AO-X,” said Jared Males from the University of Arizona. 

“The big improvement in resolution and sensitivity over today’s telescopes will open the most exciting science case imaginable: looking for life on those planets by focusing on their atmospheres,” he enthused.’

Read more at the original article: “The Giant Magellan Telescope ushers in a new era of astronomy” by Eric Ralls