Last night was our fourth on-sky night. It also ran right in to our instrument removal/moving day. So, we went from taking a nice long dataset of beta Pictoris directly into taking off cables and connectors for our electronics. I’m still awake, despite feeling like someone dropped a truck on me, so I might as well ensure the blog gets done. Our dozens of readers are no doubt itching to hear about MagAO-X’s performance on its final on-sky night of 2019B.
I’m happy to report things went pretty smoothly! We observed Trapezium, a set of bright and well studied stars that will give us our astrometric solution (by knowing where they are, we can figure out how far apart and what orientation other stuff is). We observed beta Pictoris for a few hours on either side of transit, obtaining a vAPP + ADI dataset. We started off by optimizing our image quality and took Strehl measurements in a few different filters, resulting in some exceptionally sharp z’ band images of HD 9053:
Kyle worked on focal plane wavefront sensing, following the work of XWCL alumna Dr. Kelsey Miller (now at Leiden Observatory). The basic idea is using a little bit of the star light at the focal plane of your science camera to provide information on the real, honest-to-god wavefront error as experienced by the starlight at all optics downstream of the main wavefront sensor and correcting deformable mirror. In other words, yet another way of pushing light back where it belongs to make the sharpest possible images.
In unadaptive optics news, we captured Sirius A and B on our acquisition camera. Just for fun. Here they are:
Laird and Alex worked the first half of the night, but went to bed earlier so they could supervise the crane maneuvers to remove the MagAO-X optical table and legs. The PFS instrument is taking our place on the Nasmyth platform after lunch, so we need to get everything squared away before then. For my sake, and the sake of the instrument, I’m glad it’s in the hands of people who have had some sleep.
Jared, Olivier, Kyle, and I decabled the electronics rack and the AO Operator Computer, and got them safely stowed away until this afternoon when we’ll get them ready for shipment and/or storage. We rode down the hydraulic lift with our computers and rack of electronics. Someone made a comparison to going down with a ship.
After which, we all agreed it was time to collapse into bed.
Except for Dr. Olivier Guyon, who had to call into a meeting.
I should be sleeping right now, but according to your MagAO-X song of the day there ain’t no rest for the wicked…
Tonight marked MagAO-X’s return to doing AO on starlight rather than an internal calibration source. The Observatory kindly allowed us to remain in place on the platform, so our return to operations was as simple as turning off the lamp and closing the loop on the first bright star we tried.
I’m lying to you, of course. The calibration that had worked so well on night #2 didn’t look nearly as nice when we booted up the system this evening. Alex and Laird had to open up the instrument to make fine adjustments to our pupil image positions. New response matrices had to be taken as well. “But I didn’t change any of this code!” was uttered many times, by many people.
Then we closed loop on a bright star. And it went great. We imaged π Pup and its companion. We even were able to hold on to an Airy ring around the companion! All this, in 1 arcsecond and above seeing (a far cry from Las Campanas Observatory’s trademark 0.5″).
We took the opportunity to record the AO instrument builder’s favorite video: the “now you see it, now you don’t” video.
Of course, capturing this video involved some pretty advanced optics:
Kyle and I drove the twin MagAO-X science cameras tonight. We took some data on pi Pup in various filters for Strehl ratio measurement, measuring the foci in various filters with Maggie’s focus script.
We put in our narrowband and continuum methane filters, which will eventually allow us to perform simultaneous differential imaging of exoplanets and detect methane absorption—something we see in planets closer to home, namely Jupiter. For this, however, they were just the narrowband filter available in the instrument best suited to the below-average seeing. (Shorter wavelengths are harder to correct, and our H-α filter would not have looked too good in the conditions we had.)
Next we looked at a close (0.144″) binary, HIP 38160. This wasn’t intended to be a challenging target in terms of contrast, but we were heartened to see it in the dark hole formed by our vAPP.
We also took an on-sky response matrix. This calibration step provides a mapping between our system’s deformable mirror commands and the resulting signal on our wavefront sensor.
We got some good data tonight, learned a bit more about how the system behaves, and have big plans for tomorrow night. (Of course, we also need to move off the platform immediately following that night, and off the mountain shortly after that. Fortunately for Dr. Males and the limits of good taste in blog titles, we’re not getting past “fourth light” this run.)
Today (and tonight) is first light, the special time in every instrument project where you finally use it to look at astronomical targets instead of test light sources. This is also a twenty-four hour workday, with a full day of instrument preparation followed by a full night of observing and commissioning.
I suggested that Jared, as P.I., should write the blog. He suggested that, as the P.I., he was concerned with weightier things than blog posts. (Or, at least, that he should be.) Indeed, the MagAO/VisAO first light blog post was written by a graduate student.
I’m too tired to write good code, but I have mustered what’s left of my wits to bring you an account of MagAO-X’s first light night.
Last night, we held a meeting in the Aux (the auxiliary building that sits between Magellan Clay and Magellan Baade) where we planned a hilariously optimistic timetable for the day’s work. We’d be aligned to the telescope by lunchtime, have our electronics cabled shortly after, and use our copious free time to catch up on the software fixes and backlog of necessary functionality while we waited for sunset.
Needless to say, that did not happen on our schedule. It turns out that aligning an instrument that weighs a literal ton to a telescope is tricky. Laird, Alex, and Maggie sent a laser up to the secondary mirror and back to verify the alignment of the system, pivoting the entire optical table until the axes were aligned within … well, I don’t know the exact figure, but it’s not very many minutes of arc. Arcminutes are small, 1/60th of a degree each. (I tried to come up with a clever and easily-comprehended scale comparison, but I’ve been awake 24 hours and I leave this as an exercise for the reader.)
This (and other tasks) took us from morning until 10 PM, as these things tend to do.
Once the table was locked in position, we had to connect the delicate DM cables. You wouldn’t think “plugging something in” would be a 4 person job, but each connector gets a wipe down with two different solvents, ESD protection equipment is required, etc. etc. Jared, Kyle, Alex, and I did that. Miraculously, the DM came alive with zero stuck or otherwise non-responsive actuators an hour later! This could very well have been a three or four iteration process, so getting it in one go was great.
Afterwards, we had to make the dome “shipshape” (did you know Jared was in the Navy?) by clearing the platform of discarded zipties, cleanroom gowns, grad students, etc. We ended up opening up to clear skies at 12:30 AM. Our telescope operator, Mauricio, had been patiently waiting since before sunset for us to get our show on the road, and I think he was glad we made it. (It would have been a sad night of telescope time if we hadn’t!)
Next, we needed to get light down the pipe. Just because we’re fairly well aligned to the telescope doesn’t mean we know where a star will land on the detectors of a brand new instrument. Furthermore, we were offset a fair bit from the normal in-focus position, so a new offset had to be determined experimentally.
At 1:04 AM we had starlight on our acquisition cameras, and by 1:18 AM we had closed the AO loop on the “woofer” DM. Considering how many things have to work for this, getting it within 14 minutes on the very first try is practically unheard of. We had the MagAO-X / XWCL North team calling in via video chat to share in the experience.
While Jared, Olivier, and Kyle worked on boring stuff like making the AO loops correctly offload corrections to the telescope, I busied myself with far more important tasks in the MagAO-X Web GUI—like adding flames to the display that appear when the loop is closed.
I don’t wish to understate their accomplishment: they got us running in closed loop on our woofer, tweeter, tip-tilt mirror, and the telescope itself (via pointing and focus offsets).
I on the other hand… well, see for yourself.
With that essential functionality implemented, I took a break, along with Laird, Maggie, and Alex, to enjoy the Milky Way and southern sky. However, we were besieged by goats.
We were so excited by the actual moment of first light that we didn’t do the best job of documenting it for you, gentle readers. Maggie, the hippest member of the group, did capture it for her Snapchat story, however:
And I had the presence of mind to video the acquisition of our first star (but then neglected to video its appearance on the higher-resolution science-grade cameras):
When I came up to the control room at sunrise, I was surprised to find our telescope operator politely insisting to Jared that it was actually time to close the dome and stop working. (Well, not that surprised. Observers are always pushing their luck with the sun!)
This was the first of four nights of MagAO-X commissioning. I think we acquitted ourselves pretty well, all told. Fortunately, as you can see, our P.I. is no stranger to the adaptive optics game.
In accordance with MagAO-X 2019B Blog Rules, today’s song of the day is Counting Stars by OneRepublic. (A repeat, apparently, but not since 2015.)
Just for today, my friends, we have an unbeatable special offer: with each concurrency bug you find, we will throw in another concurrency bug for free!
And, if you call now, we will throw in a semaphore collision bug at no charge! That’s a $49.99 value!
Call now! Or, if you prefer an event-driven programming model: let us call you with this exclusive offer!
Okay, now that I’ve gotten that out of my system: we have been vexed by concurrency bugs today. These are the absolute worst. To reproduce them, you must get everything just right. (In astronomical instrumentation, that can sometimes literally mean the stars aligning.) Then, once you’ve reproduced it, you’re still only halfway to figuring out which element of your system caused it.
To make a long story short, my PurePyINDI library wasn’t equipped for the huge numbers of elements Kyle wanted to control. Once I sorted out the locking in PurePyINDI, Kyle was able to apply his eye doctor script (previously blogged about) on more than the previous maximum of 36 modes. (Modes, for the uninitiated, are a bit like “things that can go wrong”. The more modes you can take to the doctor, the better your images will be.) Now we can theoretically access the 1000+ modes CACAO spits out when we take a system response matrix, and make our images very sharp indeed. On the way there, we get a bit of an Eye of Sauron look:
I’m not even going to tell you about the bugs in the linear stage logic we shook out today. As soon as we squashed one, we found another, more subtle one. And another. Until we were all quite sick of stages.
This was also the day of a very important MagAO-X ceremony. Today, at 9:00 A.M., Laird and Alex unveiled the dedicatory tailpiece and plaque, which surround (and cover, when not in use) the hole for the MagAO-X eyepiece.
Here’s a closer look:
According to Professor Close, it is traditional for a new instrument to be adorned with a tailpiece as a sort of maker’s mark once it’s complete. Great work, everyone!
In honor of Kyle’s Eye of Sauron, “Ring of Fire” by Johnny Cash is MagAO-X’s Song of the Day.
This was, incredibly, a zero-viscacha day. It was quite windy, a bit chilly, and there may have been a viscacha conference (¿visconferencia?) in the next valley over.
Meanwhile, in MagAO-X land, we continue pushing buttons on our computers and watching what happens. I promised a peek at the MagAO-X web interface, so here’s part of it… that no visiting observer will ever see!
While most of the web-based interface will be designed for the needs of guest observers, this screen is definitely an “authorized personnel only” deal. With it, you can remotely power on or off anything in the instrument! I was authorized by Jared to toggle the acquisition flip motor power on and off during testing.
While it was a zero-viscacha day, it was also a one-snake day! Jared encountered a juvenile Philodryas chamissonis on his run. This species is known locally as la culebra de cola larga. In a juvenile spirit, I feel I should share that this could be translated as either “long-tailed snake” or “long-butted snake”.
Following Emily’s theme of Firsts, and because I’m very unlikely to have the chance to attach this song to the actual first light post: “First Light” by Balmorhea.