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CfAO Fall Retreat: high contrast chats in the hills

Hello from Arizonans in California! I just got back from the UC Santa Cruz Center for Adaptive Optics (CfAO) Fall retreat, where members of the AO work through some of the pressing problems in the field. This year was focused on High Contrast imaging testbeds, lessons learned from Magellan’s MagAO-X and Subaru’s SCExAO and what might be in the cards for Keck, and a round up of adaptive Secondary progress – LBTO, MMT, and the future of IRTF, KECK, and beyond.

The Arizona Telescopes representing, Me representing MagAO-X (Magellan Clay), Robin and Jacob the Toronto part of MAPS (MMT), and Sam Ragland (LBTO)

Some of the likely suspects were around, namely Jacob and Robin from UToronto representing MMT calibration work and Sam Ragland from LBTO operations. Thanks to a very generous student scholarship from the workshop organizers, I was able to attend and represent MagAO-X’s progress.

If someone had taken a picture of me presenting, it would look a little like this.

Sam’s update on the LBT’s progress was some of the most concrete work concerning a long-term Facility adaptive secondary, in this case using adOptica technology. Sam discussed the re-coating of the secondary, and future plans, including adopting an ASM from CHile, close to this group’s heart.

Sam Ragland giving an update talk on LBTO’s work with Adaptive Secondaries.

Jacob got the longest student talk of the conference, and got to spend an hour discussing his method for calibrating on sky. A key difference between the LBTO and other telescopes discussed being that LBTO is a Gregorian design with an intermediate focus that allows for daytime calibrations of their secondary. MAPS and systems like IRTF and Keck are Cassegrain design with no focuses before the primary, and can only take calibration matrices on a bright star on sky. Making the operating software and calibration procedure robust in the meantime is a huge step towards making these systems reliable and facility class.

Jacob Taylor presenting on one method MAPS uses for on sky calibrations.

We also got one last GMT talk from Antonin, who has recently moved from his role on GMT to the AO scientist for the Keck twin 10ms. He gave an update on the current design of the GMT adaptive secondaries, which will be using a similar technology to what’s currently on LBT. In fact, we learned that the rigorous modeling and testing on the GMT prototypes solved a resonance issue that LBT had unexplained.

Antonin Bouchez reprising his past role of GMT AO lead to talk about advancements in the GMT secondary design. He has recently accepted an AO position at Keck.

I cannot express how grateful I am to have a community that shares and collaborates as this one does. Even though MagAO-X is already built, there’s a lot to learn from the discussions that Keck is having about their own testbed. As in, what areas of interest are already met by our technology? What new avenues are being pursued? And where do all fit in the the US high contrast family?

Took a quick break to see the hills of Santa Cruz

Thank you to everyone who made this conference so fruitful! And to the organizing committee for the student scholarship.

Conference participant photo, filtered by who stayed till Sunday.

Song of the Day

Berkeley Girl by Harper Simon

MAPS Oct. 2023B Night 4: That’s a wrap

Tonight we had great weather: low winds, moderate humidity, good seeing (0.6”–0.8”), and spent the whole night from civil dusk to civil dawn on bright stars near zenith! We stuck with the IR WFS and did calibrations and noise measurements all night long. For example, here is a Hadamard Matrix measurement using CACAO to look at the inter-actuator stroke:

[Image description: CACAO GUIs showing pyramid pupils and weird spirally shapes commanded on the ASM.]

And here are the CACAO and ASM control screens:

[Image description: Pyramid pupils and ASM commands per actuator.]

And we got some PSFs with MIRAC (although we only got up to 30 modes closed so I don’t have a good AO-on/AO-off sequence), here are some nice L-band speckles:

[Image description: Speckly un-corrected PSF at L-band.]

We compared the latency measured with the visible WFS (top) and the IR WFS (bottom):

[Image description: Two scatter plots of latency tests.]

Video of the night: Inspired by all the animals we’ve seen at the MMT or the drive up here (jack rabbits, owls, grey foxes, skunks, and… baby coatis!), here is a video of coatis looking like brontosaurs if you run them backwards:

[Media description: YouTube video of coatis walking, video has been reversed, and the Jurassic Park Theme music is playing. They look like brontosaurs!]

MAPS Oct. 2023B Night 3: 5 for 5

Tonight felt a lot like whiplash, from tired to energized to tired to energized, from starry to humidity to starry, and from failure to fix to failure to fix!

First of all the MAPS daytime/nighttime/whenevertime support crew (Oli, Grant, Dan) drove up this afternoon with the repaired (by Ken) bias board for the CCID-75 LittleJoe controller, as well as the IR dichroic for the Saphira. Unfortunately once we plugged in the board, we were still unable to communicate over serial. Manny’s next guess is we may also have a problem with the power supply. So ultimately that will require more lab testing and repair. Instead, we’ll use our other WFS for the rest of the run.

Anyway, so it was time to get on sky. Here are all the good AO setup stars, as defined by searching Simbad for zenith-y and bright:

dec  > 20 & dec <  50 & vmag <  2

Plus I added in Theta 1 Ori C for good measure(ments). (And actually Alpha Gem isn’t a good AO setup star, as it’s a binary with two very bright A stars only a few arcsec apart — but it’s zenith-y and bright.)

Airmass curves for the good (zenith-y and bright) AO setup stars, plus Theta 1 Ori C. [Image description: x-axis is time, y-axis is airmass and altitude. Stars are Alpha Lyr, Alpha Cyg, Alpha Per, Alpha Aur, Beta Aur, Beta Tau, Theta 1 Ori C, Alpha Gem, Beta Gem, and Eta UMa.]

Oli, Grant, and Dan then switched out dichroics and we moved to Deneb (aka Alpha Cyg) and they were about to complete the alignment when…

More humidity rolled in! Noooo! We were shut from about 9pm to 3:30am, and Oli and Grant became night crew too.

When it cleared up again, we got back on sky — this time on Beta Tau (real name: Elnath). We found it, aligned it, saved all the offsets — and tried to switch to a new star — and the offsets no longer worked! After some telescope dancing, we (Rory, Brian, me) realized we had the wrong units for our proper motion coordinates. Sigh. So I mostly* fixed that, and now we are off and running! [*I fixed the algebra but not the trig yet — just to do it as quickly as possible by hand — and the trig has only mattered once in my experience thus far, on Proxima Cen (which is apparently the highest-proper-motion star, with a large enough dec for the cosine to matter), that I’ve ever locked on.]

Here’s an IDL code snippet for future posterity:

;; Proper motions are given from Simbad in (Cartesian) mas/yr
ans = simbad_data(star)  ;; Calls the function simbad_data.pro

;; Returns ans.pm_ra which is RA proper motion in mas/yr
;; And ans.pm_dec which is Dec proper motion in mas/yr
;; And ans.icrs_dec which is sexagesimal Declination which you have
;; to convert to decimal-degrees which is the variable DEdeg

;; Magellan wants RA in sec of time per year and Dec in arcsec per year.
pmra_mag = (ans.pm_ra / 1e3) * (24/360.) / cos(DEdeg*!pi/180.)
pmde_mag = ans.pm_dec / 1e3

;; MMT wants RA in sec of time per century and Dec in arcsec per century.
pmra_mmt = ans.pm_ra * 24/3600. / cos(DEdeg*!pi/180.)
pmde_mmt = ans.pm_dec / 10.

Right now Jared, Amali, and Lauren (and Andrew remotely) are taking AO calibrations with the Saphira IR WFS, and Rory is taking data with MIRAC. Oh BTW Lauren is our new team member as of this week, her first day was our first night on-sky, and she’s doing great!

[Image description: Jared, Amali, and Lauren at work on AO, sitting in front of their operator stations.]
[Image description: Rory working on MIRAC at its operator station, and Brian at the Telescope Operator station.]
[Image description: Background-subtracted MIRAC un-corrected PSF at L-band.]
[Image description: IR WFS pyramid pupils.]
[Image description: Acquisition camera un-corrected PSF in the visible.]

Anyway, after our 0 for 5 first night, it’s great to be working with 5/5 — (1) stars are visible, (2) telescope is allowed to open, (3) conditions are safe enough for ASM, (4) AO hardware is working, and (5) science camera is ready!

And… the loop is closed just as we passed into civil twilight from nautical (having gone well past astronomical twilight)! (This is why we always get the full-moon bright time, our tiny pixels and kHz framerates don’t care about background light except for the actual Sun itself.)

And now for The Video Of The Night… I forgot to bring my Pilates travel equipment, but I can do a little bit of a workout just rotating my myofascia in spirals like in this video by my Pilates coach, “Spirals on the Cadillac for MyoFascia Release” by Arlene Corcoran:

Spirals on the Cadillac for MyoFascia Release by Arlene Corcoran

MAPS Oct. 2023B Night 2: Water falling from the sky!!!

As a current resident of Arizona and a former resident of New Mexico, part of me must celebrate when water falls from the sky in these drought-stricken drylands or deserts. As an astroengineer and astrophysicist, it does make observing …difficult. Either way, it’s still beautiful:

Afternoon at The Ridge. [Image description: A mountain scene straight outta the SouthWest. The valley floor is covered in brown rocky foothills that look like choppy waves in the ocean. The nearby mountainside is covered in dark green foliage with a scrubby texture. The sky is filled with thick heavy dark rain clouds. Yet a beauiful orange glow peaks through a gap below the clouds and above the distant valley where a sunbeam illuminates shafts of rain falling in the distance.]
A photo of the MMT today. [Image description: In the foreground are the crowns of some green and brown pine trees. In the middleground there is some sort of a brown ridgeline, kinda hazy. In the background there is white mist/fog (where the telescope dome is, but cannot be seen).]

You’ll recall yesterday we had trouble with our WFS controller. We reached out to our network of contacts for a spare part. We also began preparations to switch to our other WFS. And we even opened for around an hour tonight in a gap in the humidity and clouds! But we need more time… so we’re staying hopeful for tomorrow night.

The video of the night is “OUR LAND Episode 5: Dry Land”

OUR LAND Episode 5: Dry Land from The Greenhorns on Vimeo.

MAPS Oct. 2023B Night 1: 0 for 5

What’s this, another MAPS run? Yup, the moon is almost full, and here we are again!

Unfortunately tonight we are 0 for 5 on AO engineering/commissioning productivity. Here are the 5 things:

  1. Can we safely open the dome? No, the humidity is so high that condensation could ruin all the sensitive equipment.
  2. Can we safely expose the ASM to the elements? No, the wind is too high, it could damage/contaminate the shell.
  3. Can we see stars? No, there are clouds. Lots of very thick clouds.
  4. Can we close the AO loop? No, the controller of our wavefront sensor camera detector failed.
  5. Can we get PSFs with our science camera? No, it took longer to remove the previous instrument so longer to install ours.

Well the best night to have instrument failures is when the weather is bad anyway. We’re working on a solution. And now it’s time for bed.

No way we were opening tonight.
[Image description: Photo of the observatory status screen showing humidity at 99%, winds at 40.1 mph, and a completely socked-in all-sky cam.]
Part of trouble-shooting the Little Joe controller involved racking out the computer and directly connecting it to the controller, to make sure it wasn’t the extenders. Manny discovered the problem when he started examining individual boards. [Image description: Manny adjusts the cables and connectors of a computer placed below the Top Box, with cables directly connecting it to the instrument.]

Blog rules:

There must be a post every night.

There must be a “Video of the Night.” Something interesting to share. A song is allowed.

Video of the Night: “How this midcentury modern house harnesses the sun”