MIRAC – Page 2 – Extreme Wavefront Control Lab

MAPS Dec. 2024B Night 3: MAPS “Pop” Culture

‘Twas the night before running AO, when all through the telescope
The wind was violently stirring, we had lost all our hope;
The MAPS team decided that the night would finish
In hopes that tomorrow the gales would diminish;
There are 52 more lines in this old-time poem
So I will write the remainder of this blog in the way that we know ’em

༄ ⋆⁺₊❅.⁺˚⋆｡°✩₊･:*༄:｡

As soon as I stepped outside, I could tell tonight was the night we would be able to start running AO. The sky was clear, and the roaring winds of last night were gone.
It was silent… too silent. I couldn’t help but feel as if something else would soon stir up our night.

A nice, clear, calm sunset from the Bowl dorms

Another stunning, beautiful sunset. Photo credit: Bianca Payán

We all arrived at the telescope and set everything up just like any other night: Bianca and I filled BLINC and uncovered the science cameras, Amali booted up the ASM and prepared to start up CACAO/AO, Ben, our telescope operator, moved us to our first target, and Krishna and Jorge confirmed the absence of the target viewed from MIRAC.

Wait. What? Where’s the star!? Krishna and Jorge scramble around their work station trying to understand what is going on. Everything was fine yesterday! Why can’t we see our target tonight?? After two days of alignment, they are confused as to why this is happening.
Minutes pass by. *scramble scramble*
No star. *clickity clack*
Still no star. *brrrrrr… pop, pop!*
Popcorn is done!

In the heat of the moment, ~~Krishna~~ an ASU grad student (who is also looking to buy a car – check previous blog) fuels themselves with popcorn, hoping the sustenance will give them comfort in troubling times as well as the power to solve the issue. Everyone else joins in, munching on popcorn, as a call is made to MIRAC P.I. Jarron. The unnamed grad student’s popcorn munching intensifies. Right as Manny and the MIRAC team are about to head up to the chamber to delve into the instrument, a beautiful, amoeba-like blob appears on the MIRAC viewer. A star! During the stress-eating frenzy, we moved to a new target, made various telescope movements, fixed coma between the primary and secondary, and adjusted voltages on the MIRAC chopper. The combination of those actions allowed us to see our target on MIRAC as we desired.

While we waited for Amali to get CACAO running, a few of us decided we wanted a break from staring at the sky on a screen so that we could instead stare at the sky with our own eyes. Conveniently, the Geminid meteor shower was happening tonight, and we were in the perfect place to view it. To my surprise, the meteors looked significantly brighter and closer to us than when viewing from Tucson. I stood out there for 20 minutes, attempting to get a picture of a shooting star for the blog (I am always thinking of you). I had hoped to capture a picture of a shooting star coming out from Orion and heading towards the telescope dome, as if Orion himself was shooting it. It got cold, and my arms were sore from holding my phone up in the sky, so I gave up and went inside. I shall leave you with a sky cam image instead.

Geminid meteor (circled in red) seen from the MMT sky cam.

We go back inside to continue working, still feeling the energizing effects of the popcorn that fueled us. Throughout the wee hours of the night, Amali works towards closing the loop on 50 modes. As expected, she is able to successfully do this, thus confirming we are back on track to continue where we left off in August! (For those of you who didn’t know, pushing the ASM to 100 modes during the August run resulted in the loss of 24 magnets. To keep things short, software issues lead to magnet detaching issues.) Four months of hard work pays off! Despite the seeing going between 1.5 and 2.2 arcsecs, Amali continues working. We even verified that CHAI responds appropriately to overheating actuators by going into ESTOP – we have learned this is a crucial part to not losing 24 magnets. Meanwhile, Krishna spends the entire last half of the night coding away, developing a script to find centroids of hot pixels. That popcorn really does work. Thank you, Manny!

MIRAC PSF of 50 modes.
Closed loop → open loop → closed loop

Krishna’s plot showing a MIRAC image and its corresponding PSF. The image is in L-band with the AO loop closed on 50 modes. The FWHM of the PSF is 0.13″ which is also the proposed slit width for the soon to be commissioned ARIES spectrograph!

The song of the night is “Popcorn” by The Muppets.

MAPS Dec. 2024B Night 2: Windy Boogaloo

We started the night with a group photo featuring the stars of the show: the 6.5-meter primary and our beloved ASM watching over us from directly above our heads. It’s a good thing Ruby, Dan and the MMT day-crew gang ensured its secure installation.

Courtesy of TO Ben Kunk. Peep Amali in her muppet coat! She’s just too cool for French fashion school.
(no muppets were harmed in the making of this fashion statement… that we know of)

Bonus photo! Obligatory mirror selfie with the ASM, courtesy of Krishna. In retrospect, we raised our hands in victory too early, we didn’t yet know how the night would go.

Amali and I are present as evidenced by the extra hands in the back, Krishna and Jorge are just really tall

We headed down to get work started and within the hour Grant, Oli and Maggie had aligned the dichroic. Amali’s judicious eye achieved us decent enough pupils that we could start looking for the culprit actuators keeping us from amazing pupils. Good progress so far!

But if there’s one thing I’ve learned on my handful of MAPS observing runs, it’s that the time equivalent of at least one night will be forced from our hands by adverse weather. This was to be our windy night, so around 7:30–a little over an hour after opening–we closed the telescope.

While we held out hope for the winds to wind down, Maggy, Oli and Grant kept us company. Manny found a floor heating pad to fight off the cold reaching up through the ground. Much to our dismay, however, a mouse had eaten through part of the power cable and after 7 glorious seconds of foot warming, the pad sparked and gave out. Thankfully, our boss was uninjured, our only misfortune being that our toes were none the warmer. Such is the price of commissioning magical mirrors.

Around 11 PM, Oli, Grant and Maggie called it a night and headed down the mountain. They made it back to Tucson safe, a testimony to our team’s spirit raging against the wind.

As we waged a war of attrition against the gusts, Amali trained Lauren and me to check how individual actuators respond to a “sweep” of current.

Intermittently, Jorge kept our spirits up with Dad jokes, Manny made us popcorn, and Krishna read abstracts from the day’s arXiv feed aloud. (Yes, instead of doom-scrolling social media, Krishna scrolls through the latest astronomy and sometimes machine learning papers on the daily.)

Alas around 3 AM, the wind forecast pronounced we’d lost this battle and it was time to call it a night and head to bed.

WE INTERRUPT YOUR REGULARLY SCHEDULED PROGRAMMING TO BRING YOU THIS IMPORTANT MESSAGE:

Krishna is looking to buy a car! If anyone is selling, any and all (legitimate and non-Craigslist-based) leads are greatly appreciated! He isn’t really picky so long as the vehicle is in good condition and runs nicely, but his top contenders are currently any model of the following makes:

Ducati
Kawasaki
Indian
Yamaha

Yes, this really exists! Totally unrelated: go watch *The World’s Fastest Indian*, you won’t regret it

Be present, enjoy nature

In keeping with Maggie’s blog rules, I give you a view of the MMT from the bowl dorms before heading up to the very same. Not only did this moment allow me to admire the mountain’s beauty, but it also made me wonder if the location of the bowl dorms along the winding road to the summit was determined by geography or by a thoughtful mountain road engineer who thought this vista would serve as the perfect inspiration for a night of hard work. Or, maybe some combination of the two.

It’s almost indiscernible, but the wind is starting to pick up

Song of the Day

Before Jefferson Starship (“We Built This City”, “Nothing’s Gonna Stop Us Now”), there was Jefferson Airplane. The song of the day is Planes, by Jefferson Airplane:

MAPS Dec. 2024B Night 1: Who knew nasmyth platforms make you privileged?

Hello! I am a former MagAO-Xer cutting her teeth in the adaptive secondary world as a new member of the MAPS team. Last night, as winds hurdled through the dome, and I was crouched under the MIRAC mid-IR imager attached to the MAPS topbox (aka WFS unit), trying to see what knobs my fellow optical engineers were turning, I realized how privileged I have been in my observing experience. In contrast to MAPS, MagAO-X is fed by a tertiary mirror and mounted on a nasmyth platform next to its telescope. You are somewhat shielded from winds and there is far, FAR less crouching to adjust a filter wheel or a beamsplitter. Also, you know, the private chef thing at LCO.

Private chef or not, you can’t beat an Arizona sunset.

Despite these brief moments of discomfort, I am growing to greatly enjoy my new MAPS team! One of my favorite moments of the night was an attempt to rotate the pupil stop wheel. One of our optical engineers, Oli, was laying under the instrument fiddling with a knob that didn’t seem to be turning much of anything. We were getting live feedback from our technical manager, Manny, via radio. I asked Oli, “Do you think it’s broken?” Oli mused, “I don’t know, I am just sort of wiggling it.” Then, via radio, Manny exclaims “Stop! That’s it!”. If that doesn’t sum up the experience of optical alignment, nothing does.

We started the night by trying to get light onto the MIRAC detector. This involved reinstalling a dichroic in the topbox to feed our WFS and see if our source was centered on the dichroic, as light passes through it to feed BLINC which feeds MIRAC. This whole process involved a variety of sources which included some very bright stars, the moon, and everyone’s favorite giant planet – Jupiter!

Left: Light on MIRAC! Right: An excited group of AO operators and engineers (trust me they were happy about it)

Next, we tried to center the rotation of MIRAC – ie determine whether or not it is being fed by on or off-axis beam. If the star moves in an arc across the detector, it is being fed by an off-axis beam which we can correct with the ASM’s tilt. If the star stays stationary during the rotation, MIRAC is being fed by an on-axis beam and we are golden.

We were able to successfully center the rotation. Photo cred: Amali

Our next step of the night was to align the dichroic to the WFS so we could actually begin playing with the ASM and start working through Amali’s extensive wish list of technical tests. Unfortunately, we got clouded out and had to close. That didn’t stop the team from using our brain power though. Visiting observers from ASU, Krishna and Jorge, entertained us with geographical quizzes where we got to guess the capitals of each state and the locations of states within India. Guess which one we were better at!

Jorge trying his hand at placing the states within India. I’ll say he had moderate success.

Here are some other cool shots I took throughout the night:

Blog Rules

As the initial blogger of the run, that means I get to set some ground rules. I’ll keep it simple. Song of the Day required, and you must included a pretty shot of the mountains around you so we can be sure everyone is appreciating the beauty of this place.

Song of the Day

Messing with BLINC, which includes a set of relay optics to feed MIRAC, kept making me think of that line “play that Blink-182 song that we beat to death in Tucson, okay”.

MAPS Aug. 2024B Night 6: On and Off

Welcome to the last blog for the MAPS August 2024 observing run!

The evening started off with Grant and Oli performing an LED strip test that would allow us to more clearly see out of focus images on our pupil lens and visible wavefront sensor. The LED light strip was placed in front of the ASM, along the radius of the shell. Our pupil image was clearly out of focus. Ideally, the circles of light (each individual LED bulb) should not be overlapping. They should look as they would if you were to look directly at the LED strip itself. The VIS WFS image looks better, as you can see more defined pixels of light.

Out of focus pupil image. If you own an LED light strip and ASM, you can replicate this at home!

LED strip test on the VIS WFS. WFS pupils should not normally look like this.

After waiting for a few storms to dissipate, we get straight to doing some AO. Amali closes the loop on 50 modes, then closes on a whopping 100 modes shortly after. The 50 mode loop had a 1.4 lambda/D full width half maximum, and the 100 mode loop had a 1.8 lambda/D FWHM. GO TEAM! Tonight’s honorable target was FK5 0672, theta Herculis.

Open loop for comparison. Pupil and PSF quality courtesy of atmospheric turbulence.

50-mode loop on and off. Video taken by Amali Vaz.

Bonus Jared quote of the night: “We need more monitors.”

Now we hand things over to Grant and Oli. They battle the on and off cloudy weather as they work on VIS pyramid alignment.

Starlight, no starlight, starlight, no starlight, starlight, no sta-

After they scrambled the topbox (moved the vis CTL and CCID75), the VIS WFS pupils looked VISibly better.

After topbox alignment. The clouds took away some starlight on our pupil image.

With our new, beautiful WFS pupils, Amali, Bianca, and I take turns taking 50 and 100 mode response matrices. The image below is a 50-mode self RM, which confirms we are sensing the same modes that are being poked.

Unfortunately, AO had to come to a halt with about an hour left of observing time. While taking some RM’s, we noticed a giant red blob on our actuator position and current map. Red blobs are not good, as they indicate contamination in the ASM. What could this contaminant be? We are not sure yet, but it could be anything from a detached magnet to a bug seeking warmth.

That brings us to the end of the August 2024 MAPS run! I haven’t even hit the one year mark of working with the MAPS team, but I can still say that I am proud of how far we’ve come since my first run.

Goodnight MMT, goodnight air, goodnight stars, goodnight ladybugs and abnormally large daddy long leg spiders that are everywhere.

:･ﾟ✧:･.☽˚｡･ﾟ✧:･.:

As we all make our way home, I would like us to keep the song of the night in mind: “On the Road Again”, but specifically Donkey’s version from Shrek.

MAPS Aug. 2024B Night 5: Simulations & Storms

The duality of nature is something I’ll never stop wondering at: my first post came to you on a night so action-packed, I felt incapable of writing every detail down. Last night, however, we didn’t leave lightning shutdown.

To bide the time in hopes of some sky-time, Amali guided me through the MAPS CACAO simulation; from starting up the server, deformable mirror and wavefront sensor, to closing the loop with 20 modes, 50 modes, and finally 100 modes. Hopefully this means we’ll be able to reach 100 modes on-sky!

MAPS CAAO Simulation: 20 Modes!

Next, Lauren was shown the ways of simulated CACAO. It was comforting to know we wouldn’t break the ASM since this was only a simulation, and it was alright to push the mock-ASM to its limits and discover what not to do to the real deal. Apparently, completion of the simulation means I am now prepared to operate the AO system on-sky solo. But, I still feel like a tenuous sapling whose very existence/job/ASM is threatened by anything stronger than a mild breeze.

Amali’s pedagogy then dictated Lauren and I teach Parker how to operate the MAPS simulation. Thusly, we discovered the gaps in our learning and may have unintentionally confused Parker in the process but, he did succeed in reproducing a 20-mode loop. Maybe we didn’t do so bad after all? Our next step towards becoming strong AOaks is to write the simulation steps in our own words. Gee, it’s a good thing lab classes were a requirement for graduation; who would have thought writing reports was so important? (I jest, I jest)

The word of the night is Arizona. Talking to Yoav, I was reminded that not only does Steward Observatory and the University of Arizona contribute significantly to astronomy and humankind’s exploration of space; but so does every University in Arizona. We are strengthened by our inter-university collaboration, now more than ever. In this sense, I dare to say Arizona means ad astra per intellectum et cooperante–to the stars through understanding and collaboration.

Now, I would love to explain the majesty of the storm that kept us from opening, but words would not do it justice. So I’ll let the photography of our talented telescope operator, Brian Pinault, speak for me. Ever the diligent guardian of our invaluable tools, Brian captured this moment of volatile yet sublime nature while visually surveying the storm’s trajectory.

In honor of the storm, the song of the night is The Tempest, Op 18 by Pyotr Ilyich Tchaikovsky.

I’d like to add a bonus to tonight’s post. If you don’t already listen to Ologies, the science podcast by Alie Ward, then you are missing out. Let me present to you one of you new favorite listening experiences with the episode on Fulminology, the Study of Lightning. Check it out, or your chances of being struck by lightning may increase! (again I jest, I jest)