The biannual Adaptive Optics for Extremely Large Telescopes conference was held in beautiful Viña del Mar this year. Although normally a summer conference, it was held from October 27 to October 31–springtime in Chile!
The Reloj de Flores, a landmark in Viña del Mar.
AO4ELT aims to gather adaptive optics scientists from across the globe to discuss and formulate solutions to the largest problem facing the largest future-generation telescopes: wavefront sensing and control.
Wavefront sensing and control (WFS/C) is critical for the success of the massive 30-m telescopes (ELT, GMT, and TMT), whose performances are severely limited by atmospheric turbulence. For the goal of directly imaging exoplanets around nearby stars, the field of adaptive optics must come together to develop the technology and the algorithms for correcting tens of thousands of controllable elements thousands of times a second.
To summarize the talks, I would say the overall theme of this AO4ELT was the proliferation of improved control algorithms. We have discovered that vibrations and other quasi-stable error modes can dominate the residual wavefront errors of modern AO systems, and simple leaky integrators are insufficient for achieving high Strehl ratios on future telescopes.
The new controller architectures predominantly have moved towards machine learning and reinforcement learning to use data-driven techniques that don’t require precise system models. This agnosticism is powerful for adapting a single control architecture to multiple testbeds and telescopes, and we saw many talks about successful implementations of Policy Optimization for AO (PO4AO), among other machine learning algorithms.
Another common theme of the conference was the success in using older, smaller 1-m-class telescopes telescopes for on-sky prototyping and testing. There is an age-old problem of adapting technology and algorithms from simulations to testbeds, and then from testbeds to telescopes. These older telescopes are having a renaissance in utility, since AO scientists are getting crucial on-sky time without the stress and overhead of competing with observers for time on larger, more modern telescopes. This renaissance is also giving students and young career researchers valuable experience in the planning and operations of observations, something you can’t get on a testbed, alone.
Walking back from the conference at sunset, enjoying the view of Castillo Wulff.
Now, what was I presenting at AO4ELT? Having just started work with the XWCL, I didn’t have any exciting results to share for the polarimetric mode of MagAO-X, but I did share work from my Ph.D. dissertation on the upgrades and early science of the VAMPIRES instrument on SCExAO (the sister of MagAO-X on the Subaru Telescope).
Showing off my poster with glee.
Beyond the conference, I enjoyed the sounds of the sea and many of the cultural staples of Chilean food–including many pisco sours. For those who are unaware, like I was, pisco is distilled fermented grapes, basically distilled wine. A pisco sour combines the liquor with lemon/lime juice, egg white, and a sweetener. The best pisco sour I had was at the Macha restaurant, where I also enjoyed octopus by recommendation of the chef to celebrate my birthday, which fell on the final day of the conference.
Pink octopus from Juan Fernandez Island, yellow chili pepper sauce, vegetables, and sweet potatoes.
Following the conference, I had planned to explore Valparaíso and spend a few days in Santiago, but my arch nemesis, the conference bug, had other ideas. I quickly got caught up on the spanish needed to naviagate a farmacía, from pañuelos to vaporaciones (de Vick). Nonetheless I was able to seek out some cozy cafes and tasty food before my long flight back to the US.
A powerful breakfast of coffee and tres lechesWhat would you call this fork?La Florería CafeSingular RoastersI like my coffee slowMama Mia Cafe
Song of the day: Despacito (it’s the Mr. Brightside of Latin America)
It’s been a while since we’ve had a results post, but it is returning after almost 10 years.
Abstract: 2MASS J16120668-3010270 (hereafter 2MJ1612) is a young M0 star that hosts a protoplanetary disk in the Upper Scorpious star-forming region. Recent ALMA observations of 2MJ1612 show a mildly inclined disk (i=37∘) with a large dust-depleted gap (Rcav≈0.4″ or 53 au). We present high-contrast Hα observations from MagAO-X on the 6.5m Magellan Telescope and new high resolution sub-mm dust continuum observations with ALMA of 2MJ1612. On both 2025 April 13 and 16, we recovered a point source with Hα excess with SNR ≳5 within the disk gap in our MagAO-X Angular and Spectral Differential (ASDI) images at a separation of 141.96±2.10 mas (23.45±0.29 au deprojected) from the star and position angle (PA)= 159.00±0.55∘. Furthermore, this Hα source is within close proximity to a K band point source in SPHERE/IRDIS observation taken on 2023 July 21 (Ginski et al. 2025). The astrometric offset between the K band and Hα source can be explained by orbital motion of a bound companion. Thus our observations can be best explained by the discovery of an accreting protoplanet, 2MJ1612 b, with an estimated mass of 4MJup and Hα line flux ranging from (29.7 ±7.5)×10−16 ergs/s/cm2 to (8.2±3.4)×10−16 ergs/s/cm2. 2MJ1612 b is likely the third example of an accreting Hα protoplanet responsible for carving the gap in its host disk, joining PDS 70b and c. Further study is necessary to confirm and characterize this protoplanet candidate and to identify any additional protoplanets that may also play a role in shaping the gap.
Li, J., Close, L., and Long, F., et al. “Discovery of Hα Emission from a Protoplanet Candidate Around the Young Star 2MASS J16120668-3010270 with MagAO-X”
A team of astronomers has detected — for the first time — a growing planet outside our solar system, embedded in a cleared gap of a multi-ringed disk of dust and gas. The team, led by University of Arizona astronomer Laird Close and Richelle van Capelleveen, an astronomy Ph.D. student at Leiden Observatory in the Netherlands, discovered the unique exoplanet using the University of Arizona’s MagAO-X extreme adaptive optics system at the Magellan Telescope in Chile, the U of A’s LBT telescope in Arizona and the Very Large Telescope, or VLT, at the European Southern Observatory in Chile. Their results are published in two papers appearing on Aug. 26 in The Astrophysical Journal Letters.
Composite photo of the WISPIT 2 system as seen by the Magellan Telescope in Chile and the Large Binocular Telescope in Arizona. The protoplanet WISPIT 2b appears as a purple dot in a dust-free gap between a bright, white dust ring around the star and a fainter, outer ring, orbiting at about 56 times the average distance between the Earth and the sun. The other potential planet, CC1, appears as the red object inside the dust free cavity and is estimated to be about 15 Earth-sun distances from its host star. Credit: Laird Close, University of Arizona.
For years, astronomers have observed several dozen planet-forming disks of gas and dust surrounding young stars. Many of these disks display gaps in their rings, hinting at the possibility that they are being “plowed” by nearby nascent planets, or protoplanets, like lanes being cleared by a snowplow. Yet, only about three actual young growing protoplanets have been discovered to date, all in the cavities between a host star and the inner edge of its adjacent protoplanetary disk. Until this discovery, no protoplanets had been seen in the conspicuous disk gaps — which appear as dark rings.
“Dozens of theory papers have been written about these observed disk gaps being caused by protoplanets, but no one’s ever found a definitive one until today,” said Close, professor of astronomy at the University of Arizona. He calls the discovery a “big deal,” because the absence of planet discoveries in places where they should be has prompted many in the scientific community to invoke alternative explanations for the ring-and-gap pattern found in many proto-planetary disks. “It’s been a point of tension, actually, in the literature and in astronomy in general, that we have these really dark gaps, but we cannot detect the faint exoplanets in them,” he said. “Many have doubted that protoplanets can make these gaps, but now we know that in fact, they can. “
4.5 billion years ago, our solar system began as just such a disk. As dust coalesced into clumps, sucking up gas around them, the first protoplanets began to form. How exactly this process unfolded, however, is still largely a mystery. To find answers, astronomers have looked to other planetary systems that are still in their infancy, known as planet-forming disks, or protoplanetary disks.
Close’s team took advantage of an adaptive optics (AO) system, one of the most formidable of its kind in the world, developed and built by Jared Males, Laird Close and their students. Jared Males is an associate astronomer at Steward Observatory and the principal investigator of MagAO-X. MagAO-X, which stands for “Magellan Adaptive Optics System eXtreme,” dramatically improves the sharpness and resolution of telescope images by compensating for atmospheric turbulence, the phenomenon that causes stars to flicker and blur, and is dreaded by astronomers.
Suspecting there should be invisible planets hiding in the gaps of protoplanetary disks, Close’s team surveyed all the disks with gaps and probed them for a specific emission of visible light known as hydrogen alpha or H-alpha.
“As planets form and grow, they suck in hydrogen gas from their surroundings, and as that gas crashes down on them like a giant waterfall coming from outer space and hits the surface, it creates extremely hot plasma, which in turn, emits this particular H-alpha light signature,” Close explained. “MagAO-X is specially designed to look for hydrogen gas falling onto young protoplanets, and that’s how we can detect them.”
In this artist’s illustration, infalling hydrogen gas causes the growing protoplanet WISPIT 2b to shine brightly in the hydrogen alpha spectrum, to which the MagAO-X instrument is particularly sensitive. Art from Joseph Olmsted/STScI/NASA
The team used the 6.5-meter Magellan Telescope and MagAO-X to probe WISPIT-2, a disk van Capelleveen recently discovered with the VLT. Viewed in H-alpha light, Close’s group struck gold. A dot of light appeared inside the gap between two rings of the protoplanetary disk around the star. In addition, the team observed a second candidate planet inside the “cavity” between the star and the inner edge of the dust and gas disk.
“Once we turned on the adaptive optics system, the planet jumped right out at us,” said Close, who called this one of the more important discoveries in his career. “After combining two hours’ worth of images, it just popped out.”
According to Close, the planet, designated WISPIT 2b, is a very rare example of a protoplanet in the process of accreting material onto itself. Its host star, WISPIT 2 is similar to the sun and about the same mass. The inner planet candidate, dubbed CC1, contains about 9 Jupiter masses, whereas the outer planet, WISPIT 2b, weighs in at about 5 Jupiter masses. These masses were inferred, in part, from the thermal infrared light observed by the University of Arizona’s 8.4-meter Large Binocular Telescope on Mount Graham in Southeastern Arizona with the help of U of A astronomy graduate student Gabriel Weible.
“It’s a bit like what our own Jupiter and Saturn would have looked like when they were 5,000 times younger than they are now,” Weible said. “The planets in the WISPIT-2 system appear to be about 10 times more massive than our own gas giants and more spread out. But the overall appearance is likely not so different from what a nearby ‘alien astronomer’ could have seen in a ‘baby picture’ of our solar system taken 4.5 billion years ago.”
University of Arizona’s MagAO-X instrument in the clean room at the Magellan Telescope in Chile. Photo credit: Jared Males
“Our MagAO-X adaptive optics system is optimized like no other to work well at the H-alpha wavelength, so you can separate the bright starlight from the faint protoplanet,” Close said. “Around WISPIT 2 you likely have two planets and four rings and four gaps. It’s an amazing system.”
CC1 might orbit at about 14-15 astronomical units (AU) — with one AU equaling the average distance between the sun and Earth, which would place it halfway between Saturn and Uranus, if it was part of our solar system, according to Close. WISPIT-2b, the planet carving out the gap, is farther out at about 56 AU, which in our own solar system, would put it well past the orbit of Neptune, around the outer edge of the Kuiper Belt.
A second paper published in parallel and led by Richelle van Capelleveen and the University of Galway details the detection of the planet in the infrared light spectrum and the discovery of the multi-ringed system with the 8-meter VLT telescope’s SPHERE adaptive optics system.
“To see planets in the fleeting time of their youth, astronomers have to find young disk systems, which are rare,” van Capelleveen said, “because that’s the one time that they really are brighter and so detectable. If the WISPIT-2 system was the age of our solar system and we used the same technology to look at it, we’d see nothing. Everything would be too cold and too dark.”
This research was supported in part by a grant from the NASA eXoplanet Research Program (XRP). MagAO-X was developed in part by a grant from the U.S. National Science Foundation and by the generous support of the Heising-Simons Foundation.
We have reached the epic conclusion of yet another AO summer school. Stay with me, dear reader, as we have much to cover:
Day 4: The Penultimate Chapter
After 4 days in Santa Cruz, I was itching to see a patented yellow slime ball, affectionately known as the “Banana Slug.” In a sort-of slug summoning ceremony, I slipped on my slug stompers at sunrise.
The slug stompers (or slippers) in question.
The morning session began with a great controls theory talk given by Dr. Nour Skaf. Sadly, Nour did not stay at the workshop for very long, as she left to begin her new faculty position at UH IFA!!! 🙂 *catjam* *catjam intensifies*
All suffering stems from the mind.
We then heard from UCO director and GPI extraordinaire, Bruce Macintosh, about error budgets within AO systems.
Bruce and I harbor a common fear of NCPAs.
After a long morning’s work AO-ing, it was time to take a brief nap:
This photo is sponsored by UVic’s New Earth Laboratory.
Following a quick nap, we worked on an AO simulation workshop led by UC Santa Cruz post doc and HCIPy conspirator, Emiel Por. There are no photos from this activity so I will leave the visuals to the reader’s imagination.
After dinner, Parker went on a hike while others studied for quals or worked on grant applications:
Parker lichen what he’s seeing.UA+Uvic+Gemini crossover episode!
After an unsuccessful attempt to observe some stars, we gathered outside the dorms to sit on tree stumps:
No injuries occurred during the scaling of this tree stump.
We were kind enough to include this green table in our group selfie:
Selfie with a green table
Day 5: No Fish in the Microwave
The fifth and final day of the AO summer school began with an important reminder:
The banana slugs enforce a strict no fish in microwave policy.
The final day also included talks on astrophotonics, AO in space, and AO for microscopy!
As this blog post is biased towards my areas of research interests, I included a photo from Rus Belikov’s talk of EFC being done before it was cool:
Call this OG(FC).
Finally, it was time for the moment that we have all been waiting for–the AO Summer School Vision Awards 2025!
I won the award for Worst Optics (I thought about contesting but I was bribed with banana slug stickers)! And Parker won the adaptive pupil award!
Everyone wants to know what would I do if I didn’t win…Parker with the shape-shifting pupils
We then went on a social excursion to the Santa Cruz boardwalk/arcade/karaoke facility/casino/bowling alley/laser tag room!
Parker thinking about going for a swimEmmanuel and Parker locked in an epic air hockey duel.Parker and I enjoying a roller coaster.
Here’s to a successful AO summer school!
Our wild turkey participants forgot to join us for the group photo.
Just before leaving, we finally got some slug-tent:
Ring, ring, ring, ring, ring, banana slug.
I would like to dedicate this blog post to Keck’s broken dome shutter.
Another couple of days of AO Summer School are in the books! We’ve moved well beyond introductions and into the core of adaptive optics, exploring topics like wavefront sensing and reconstruction, atmospheric turbulence, and deformable mirrors. Alongside the great lectures, we’ve also had the chance to put the concepts we learned into practice through hands-on labs. In one of our labs, we explored different types of wavefront sensors (WFS) including the Shack-Hartmann WFS, and the Pyramid WFS. Below is Katie and Marcus’s groups setup for the wavefront sensor lab.
The rest of the afternoon was spent touring labs, starting with the Santa Cruz Extreme AO Lab (SEAL). From there, we got a sneak peek at SCALES (imaged below), an upcoming Keck instrument built to probe the compositions of exoplanet atmospheres.
The next lab space we visited was UC Santa Cruz’s massive marble test bed, and their shop where they test new techniques to make shells for deformable mirrors.
The final place we stopped by had a bunch of cool history about UC Santa Cruz’s involvement with optics and astronomy. In the photo below, you can see the 3 meter telescope (yellow structure) at Lick Observatory that was commissioned in 1959. Compare this to the more modern 10 meter Keck telescope structure commissioned in 1985.
On a more serious note, a washing machine was located and disaster was avoided with regards to Josh may or may not having anymore clean clothes halfway through the workshop….
While I’m sure the people are dying for some much needed Vizzy content, the campus turkeys and deer with have to suffice for now.
