MagAO-X 2024Aa Day 11: Wanderer above the sea of fog

Wanderer Above the Sea of Fog (Viscacha Edition)” by Caspar David Friedrich and an AI

The day-to-day operation of an experimental extreme adaptive optics instrument, pushing all the boundaries at once, can feel like lurching from crisis to crisis. We need to get better airflow in the bowels of our electronics rack. We need to automate the fifty-three step alignment process. We need to debug this segmentation fault in our control software. We desperately need to do laundry, but we’re unwilling to sacrifice sleep or work time.

Today, a portentous wind blew all through dinner. Jialin and Laird got on right at sunset, and it looked for a minute like we’d have an okay night. predicted calm conditions. In fact, it’s continuing to predict calm conditions.


Yes, the wind line is going into the humidity plot.

We have to close the telescope for average wind speeds of 35 mph, and it’s gusting to 52 mph. Jialin is no longer allowed outside without a tether in case she blows away.

We tried to open the door to the outdoors but nature said “no. ❤️”

The conditions at Las Campanas will blow you away.

At times like these, the hard-working AOistas thank Mother Nature for delivering exceptionally bad conditions so that we can focus on what’s important: software development, esprit de corps, and blog #content.

We did take some data before we got shut down, though. And, who knows, maybe this will all just blow over. Meanwhile, Jared was not satisfied with the amount of wind and went to get some extra fans for our instrument. Armed with a couple of graduate students, he went to hunt in the storage building between telescopes.

Inside a box cryptically labeled VisAO (possibly some viscacha-themed instrument?) were some fans for cannibalization. This will hopefully help us even out temperatures in the electronics rack.

“Hello old friend”— Jared

2024-04-24 00:00 CLST

Sparkles “Eden” McEwen turned 25 today! We only use UTC for consistency in our instrument, but birthdays are celebrated in local time.

We’re happy you were born!

2024-04-24 01:27 CLST

Wind’s dying down! Finally!

Jared took some data down at the lodge while he was checking on his laundry. Seems like he got a bit of sky rotation.

If you visit the southern hemisphere you can see the Magellanic Telescopes, discovered by astronomers in 2001.

Tomorrow’s a half-night for me, so I’m taking advantage of my last full night to file my second and final blog post for 2024Aa. Until next time, enjoy some hair-metal revival from STARBENDERS.

Song of the Day

We can face the darkness, baby. It’s all in the way you play the game.



I know we’re not the first ones to use AI image generation, but its ability to capture South American animals has greatly improved since I last tried it out.

O B E Y (prompted by Sebastiaan)
The tail-less giant mountain viscacha has not been seen since the last ice age.
The ELBT (Extremely Large Banana Telescope) (prompted by Jay)

MagAO-X 2024Aa Day 7: Anti-Lunch Lunch Club

Hard to believe I’m back here! I was so convinced 2023A would be my last trip to Chile with the MagAO-X team that I tried to do all my tourist stuff in one go last year. In the past year, I’ve defended my dissertation, moved across the country, and begun a fellowship at the Center for Computational Astrophysics of the Flatiron Institute, a division of the Simons Foundation. (That is officially how we are supposed to refer to it, officially. Unofficially, it’s just “CCA.”)

Today’s lesson is that sometimes you try your best to sleep all day and just can’t manage it, even if you exhausted yourself working the longest day. Those of us with this problem were today’s accidental day crew: myself, Sebastiaan, Maggie, and Eden. We got up for lunch and did some daytime engineering on MagAO-X.

An HDFS introduced in the first act must go on-sky by the fifth.

Maggie and Sebastiaan prepared to test the Holographic Dispersed Fringe Sensor (patent pending?) on-sky, shoring up its credibility for inclusion in the Giant Magellan Telescope project’s plans. I helped Eden get started with fixr, my Python library to read the format for our images that have been extremely reordered. I did some work on packaging fixr as well as getting various guest observer software creature comforts working consistently once again.

We all met up at dinner (save Jialin, who had to attend a class online). Tuesday is turno day, where the crew that’s been working since last Tuesday gets replaced by all new staff fresh from their week off-duty. While I will miss Sr. Verdugo’s desserts, this turno‘s cooks are breaking new ground in LCO salad bar operations. Imagine, sliced strawberries in a salad! I’ve never seen the like here before.

Josh Liberman regaled us with tales of the risks of excess cheese and the good sense of always traveling with Strunk & White’s elements of style. Katie always carries nail clippers instead. (I’m not sure why either of those were needed at dinner, but it’s certainly preferable to be well-spoken and well-groomed than the opposite.)


Meanwhile, down at El Pino, Logan Pearce was enjoying the local wildlife and natural environment.

The viscachas look different in La Serena
Wait for the green flash

Today also saw the arrival of Jialin Li, who arrived on the mountain after a one-day delay not unlike my own. (Did you know LATAM has a ninety minute cutoff for accepting checked bags? Well, I do now.)

Jialin is not only Laird Close’s graduate student but is also a heuristic interactive algorithm for observer time scheduling. Each astronomer has certain targets, which rise and set at certain times, and a certain number of nights (or fractional nights) allocated by their institution. Balancing these constraints is hard, possibly even NP-hard. Unfortunately, Jialin was incommunicado in transit yesterday, and the schedule was pulled in all directions in her absence. Sebastiaan began compiling constraints based on when people would be ready for various engineering tasks, when they’d be arriving onsite, when they’d be leaving, and whatnot.

So, when she arrived, the schedule was still very much in flux. The control room at dusk was alive with furious multitasking. At one point Logan Pearce called in from the hotel in La Serena (where she is recuperating) to try and understand the scheduling spreadsheet, which was live updating rapidly before her very eyes. After much hemming and hawing and proverbial horse-trading, an acceptable schedule solution was reached—just as the sun set.

Figure 1: Ph.D. advisor elated that his student (center) survived her travel odyssey

For tonight’s scheduled performance, the role of Dr. Alycia Weinberger was played by the understudy, Jay Kueny. Jay acquired more data of some of Alycia’s favorite debris disk targets. MagAO-X can image shorter wavelengths than MagAO+Clio could, and produces better images than MagAO+VisAO did. This means the residual light from the star doesn’t spread out as far, making it easier to detect and characterize the parts of the disk closest to the star in our images.

The bad seeing conditions we had initially mellowed out to more typical 0.5–0.6” seeing after the sun had been down for a little while, and we got some good data on HD 61005 for Alycia. Alas, it could not last. Clouds began to gather on the horizon, and the wind picked up something fierce. The telescope can’t operate in high winds, so this kiboshed a lot of our plans for the evening.

You can see what happened on the plot below, most easily recognized by the big chunk of missing seeing data. Winds got above 35 mph average, which meant we had to shut down. Since there’s never any shortage of things to do, and MagAO-X has an internal “telescope simulator” source, we attempted to make the most of this time for engineering.


While Jared continued polishing MagAO-X Halpha performance with internal calibrations, a few of us retired to the break room to audition songs for Song of the Day. There were a few rejected choices (too sad, too raunchy, contains swears, etc.) but I think I picked a good one.

Around 4:58, Sebastiaan popped his head outside and reported seeing “a ton of stars” so we all traipsed back upstairs bright-eyed and bushy-tailed… only to hear Jared say “don’t get excited.” Although a ton of stars were visible, the humidity was climbing fast, and threatening clouds were gathering in the North.

We all got less excited. As we got close to sunrise, humidity plateaued and the average wind speed stayed low long enough that our telescope operator (the incomparable Alberto Pastén) decided it was safe to reopen. At this point, science was off the menu: not only was engineering scheduled for the end of the night, but the conditions were too bad for any but the brightest targets anyhow.

The Chekhov’s HDFS introduced in the beginning of the blog post must go off by the end, so Sebastiaan quickly slotted it in to take some data under realistic 90th-percentile conditions. It was tough to keep things stable, and the dispersed fringes occasionally disappeared entirely, but we took some data of a double star and got to see all the fringes doubled. That’ll be fun to disentangle.

it’s like a dandelion!

After we finished, Sebastiaan and I stayed up for breakfast and were rewarded with this view of the valley filled with clouds trapped in the inversion.

Today’s song of the day expresses a desire for a counterfactual reality in which the clouds are absent and the seeing is always below half an arcsecond. I think that’s what they were singing about, anyway.

Song of the Day

“Say it Ain’t So” — Weezer

MAPS 2023A Day 4: What’s a couple of shmims between friends?

After the previous night’s untimely clouds, we were fortunate to have clear skies and moderate-to-good seeing all night. The MIRAC-5 team continued work on their instrument, which the adaptive optics operator Eden found extremely useful for its fast video feed showing how (and if) our adaptive optics experiments were improving their images.

I, however, mostly spent the night shmim-wrangling.

MAPS (like its cousins MagAO-X and SCExAO), uses shared memory images—shmims—to relay data at high speed from a wavefront sensor, through an adaptive optics loop, to the point where commands are handed off to the adaptive secondary mirror.

There it is! Way high up off the ground!

Of course, a shared memory image is just a hunk of memory with a hint about the type of data it contains (floating-point numbers, integers of various sizes, etc.). One could just as easily use a shmim to store a vector, or a single number, or a data cube.

One such vector was my target yesterday: the vector of “modal gains.” Each entry in the vector scales the system’s correction for that mode by the factor you provide, allowing you to correct low-order modes more strongly while easing off the high-order modes that you may not be able to control as effectively. It’s sort of like the EQ sliders on a stereo.

What’s he listening to?

Still, one may ask, what is a “mode” in an AO system? The answer: something too abstruse, dear reader, to bother this blog with.

That won’t stop me, though! You know how the optometrist fiddles around with their equipment to find the best focus for your eyes, and only then starts in with the next level: correcting for astigmatism? Well, AO systems fiddle around many times per second to get the best focus for the telescope, and the best astigmatism correction, and a few more besides. It turns out there are “levels” beyond astigmatism, accounting for even more subtle changes to the image. We need to correct those for the sharpest image possible.

That’s the short version, anyway. The long one involves math. If you’re looking for a low-stress beach read this summer, I can recommend Adaptive Optics for Astronomical Telescopes by Hardy (1998).

In MagAO-X we divide the gain controls into blocks of modes and use buttons to bump them up or down to improve our correction. MAPS does not use all the same MagAO-X software, and the two of us from the MagAO-X team were missing the fun of clicking a lot of buttons really fast. So, while Andrew develops the real, production-grade, network-enabled button-pushing infrastructure for MAPS, I brought a little bit of MagAO-X from home.

This tool replicates the UI we have for MagAO-X gain tuning, with the additional trick of a parametric gain curve. Rather than tuning the modes by blocks, one can type in some parameters to define that pink curve with a different gain value for every single mode. Clicking “Apply” then fires the numbers off into the appropriate shmim, where they are applied to the AO loop.

Of course, all the software in the world can’t change the laws of physics. Summer seems to have finally made it to Mt. Hopkins, and with it the need for active ASM cooling has become acute. It turns out that bending glass mirrors takes a lot of power, and some of that power escapes as heat. That heat, in turn, makes the whole system (red-faced and panting) call for a time-out while it collects itself.

It’s not often I wish a mountaintop were colder and windier. Tomorrow’s our last night, and we’ll have to see if we can keep our cool when it’s a balmy 54ºF at 1 A.M.

Song of the Day

“Que Sera” by Wax Tailor. It’s a groove, trust me.

MAPS 2023A Day 0: Stranger in a familiar land

MAPS is The MMT Adaptive optics exoPlanet characterization System, an upgraded adaptive secondary AO system for MMT. For the next week or so, it is installed on the telescope and the team has important engineering and science to do. To this effort, the XWCL has contributed one CACAO expert on the ground (Eden McEwen) and two remotely (Jared Males & Olivier Guyon). We tried to contribute two on the ground, but the departure of Avalon from Tucson means there was a vacancy in the dorms.

I’ve always wanted to see the MMT, ever since the daily high in Tucson cracked 95ºF (if not longer!). I expressed this wish to Manny, and someone vouched for me as “useful”, and thus did I secure Avalon’s spot for myself.

Now, on the MagAO-X team, our fearless leader likes to surprise and alarm us by turning up in unexpected places—to the point where we have a calendar tracking his movements so we know what timezone he’s operating under. Most recently, we learned he was in Tokyo thanks to Hello Kitty.


I thought it was time to return the favor, by heading up Mount Hopkins without a peep to Jared. We had it all worked out: Eden was going to write blog posts with me lurking in the background of her pictures, and we were going to wait and see if Jared noticed… but the cat’s out of the bag already.

And Eden’s asleep.

So I’m writing the blog post.

MMT, formerly the Multiple Mirror Telescope (currently the Mmt Mmt Telescope), is a 6.5-meter telescope in Southern Arizona at the Fred Lawrence Whipple Observatory. It’s part of Steward Observatory, and University of Arizona. Also the Smithsonian. Also Harvard. Everyone wants a piece of the F.L.W.O., and who can blame them? It’s gorgeous country out here.

UofSAO? Photo: Eden McEwen
That’s the MMT! Photo: Eden McEwen

The night shift left Tucson around 1 P.M. with all the food for their 1–6 days of meals in tow (depending on length of stay). With a mere hour-and-a-half drive separating their lab in Tucson from their telescope, the MAPS team has MagAO-X thoroughly beat for convenience.

The delicate optical bits were all in place well before sunset, thanks to efforts of the day team, allowing me to take this glamour shot when we opened up the dome.

Look at that little guy!

The telescope operator had kindly tipped the whole contraption over to make a compelling group photo:

Who would win: Fifteen people, or one wiggly mirror?

The night began with breezy but clear conditions and seeing hovering just under 1″. Naturally, the first bit of the night was spent debugging, aligning, and turning things off-and-on-again. (We know all about that.)

Once starlight was hitting the wavefront sensor (thanks to Oli) and the pupils were looking good and round (thanks to Robin and Jacob of UToronto): it was time for some CACAO: Compute And Control for Adaptive Optics. The same ultra-fast, ultra-flexible AO system that powers SCExAO and MagAO-X is being implemented as the new brains controlling the adaptive secondary.

Andrew and Eden worked diligently through many fiddly bits of computer plumbing to get pixels from the sensor and commands to the adaptive secondary (under the watchful eye of Jess):

Eden hard at work, with a cameo by Vizzctor V. Viscacha.

Meanwhile, in Tokyo, MAPS East was supporting the effort over Zoom:

They put those eight monitors up so they don’t have to see a bare ugly wall.

Their combined efforts got us to our final checklist item of the night: close the loop. With an hour or so to go until sunrise, the globally distributed team worked on improving the calibration and setting things up so tomorrow night we can skip right to “the interesting part.”

Stay tuned.

Song of the Day

In honor of the MAPS East team’s contributions, I submit this Japanese groove that’s been stuck in my head.

chilldspot – “mitei”

MagAO-X 2023A Bonus Feature: Santiago de Chile

I didn’t get into academic astronomy to travel, but I didn’t get into academic astronomy to avoid travel, you know what I mean?

I’m bringing the good ship Ph.D. into port in the very near future, and I have been to Chile some six times (should have been more, but thanks covid) without having seen more than observatories and airports (again, thanks covid).

After a month away from home I was exhausted and had a to-do list as long as my arm, but I decided if I didn’t take some personal travel now I never would. In the spirit of MagAO-X 2022B Day 3: An astronomer’s guide to Valparaíso, Chile, I present 2.5 days in Santiago de Chile.

I gratefully acknowledge the advice and suggestions of Dr. Matías Díaz (lately of drone-piloting fame) and the MagAO-X Chilean Cultural Attaché Dr. Susana Henriquez.

Day 0:

On Sunday the 19th, we left the observatory. A van transported us and the luggage of a one-month stay (multiplied by four people) from Las Campanas down to La Serena airport.

We obtained Kunstmann Torobayo (times four) and papas fritas, as is tradition.

Sebastiaan, Jared, Jeb of the XKIDS, Eden, and myself at La Ultima Llamada (La Serena Airport bar)

After a short hop to Santiago airport, I parted ways from the rest of the MagAO-X team.

Continue reading “MagAO-X 2023A Bonus Feature: Santiago de Chile”