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”
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:
Can we safely open the dome? No, the humidity is so high that condensation could ruin all the sensitive equipment.
Can we safely expose the ASM to the elements? No, the wind is too high, it could damage/contaminate the shell.
Can we see stars? No, there are clouds. Lots of very thick clouds.
Can we close the AO loop? No, the controller of our wavefront sensor camera detector failed.
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”
The full moon is waning and that’s a wrap on the first MAPS run of 2023B! We have 3 more runs, on the full moons in October, November, and January.
On this run we successfully closed the loop with our new software algorithms, which required taking new timing data and calibrations. We also got offloading within the loop working, and made progress on our other goals. (I made an executive decision to redo how I was numbering the nights, so careful blog readers may notice I edited the night numbers in the previous blog posts, since when I was writing our telescope proposal for next semester I realized it was overly confusing to try to keep the Arizona nights separate from the MMT nights.)
Grant crosses off our top goal for this run: offloading tip/tilt to the mount! [Image description: An astroengineer writes on a white board. On the white board are the Run Goals and the Tonight Goals — one can read a few words such as Alignment, Pisces, Mount, Hexapod, Pupil, Interaction Matrix, Close Loop.]Taking a 50-modes calibration. [Image description: GUIs and displays showing the real-time pyramid pupils, integrated/averaged pyramid pupils, ASM commands, slopes, ]
Manny made cookies!
[Image description: In the telescope control room, Robin offers a plate of cookies to the photographer. Amali and Katie strategize ASM tricks in the background.][Image description: Manny is very happy to cut open the watermelon!]
Thanks everyone — run report to come.
Song of the day: Say Hey (I Love You) by Michael Franti \& Spearhead
[Median description: High energy, joyful, rhythmic song with scenes of the people of Brazil.]
Tonight is our first *official* night on the telescope schedule, as last night was originally scheduled as an MMTO M&E night (maintenance and engineering) that the telescope ended up not needing more than we did, so they let us have an extra night to focus on our alignment. Thank you MMTO!
Craig and Dan came back up to help out at the start of the night with PISCES and the Top Box, respectively. Craig trained ASU grad student Krishna and me on PISCES operations including filling the dewar to keep it at a chilly 77 Kelvin. Fun fact: PISCES has been on 4 professional telescopes on several mountains around southern Arizona!
[Image description: Three photos showing two astronomers adjusting the instrument PISCES mounted to the telescope, and filling it with liquid nitrogen.]
Unfortunately we had to close the dome because of high winds around midnight.
Luckily the software crew were able to continue debugging by our old MagAO trick of closing the loop with tiny gains on WFS noise!
So I thought I would take some time tonight to lay out all the different systems we are controlling on this run, and the operating stations. Our T.O. Ben took for this great pic at sunset: He is standing outside the dome on the ground and the telescope is tipped over looking at horizon and we are all standing on the dome floor near the dome slit. You can see some of the primary mirror (the big glass behind us) and the back of the ASM and its structure.
[Image description: 9 astro-engineers stand in a metal building that is seen from the outside. The building has a large opening and behind that can be seen a round mirror. Metal beams are in front of the mirror holding out another smaller round mirror. The faint blue twilight sky is seen in back. One of the astro-engineers is jumping for joy, the others are smiling and/or looking wind-blown.]
First we have the big picture of our AO system on the telescope. The ASM is at the top, suspended far above the primary mirror. The Top Box (labelled W-unit here) is mounted directly beneath the primary mirror, and PISCES (labelled ARIES/MMTPol here, because any of our science cameras will go in this spot) is mounted just below the Top Box. The ASM power supply and the AO reconstructor computers are off telescope in the equipment room.
[Image description: A line drawing of the MMT telescope, pointed at zenith. It is a Cassegrain alt-az telescope with a fast primary and a small, agile mount. Colored shapes and lines show how the MAPS components fit onto the MMT telescope.]
Let’s follow a wavefront as it enters the MMT. The first surface it encounters is the primary mirror which is controlled by the telescope operator (this week we have the pleasure of working with Ben):
[Image description: Several monitors at the Telescope Operator’s station showing the status of the telescope and guis for controlling its various components, web cams for viewing dome safety, star finding tools, thermal control, weather prediction and status, and astronomical and geometrical status.]
After the primary mirror it goes to the secondary mirror. The ASM is currently operated by Jess and/or Amali who use the original engineering gui written by Elwood to control the coil currents, monitor the temperatures, and apply their best lab flat:
[Image description: Jess sits in front of two monitors full of guis to control the ASM, view its actuators’ health and safety, and log his observations.]
Next let’s look at the Top Box. Here is its layout: After our wavefront encounters our secondary mirror, it goes through the primary’s central hole to the dichroic just above PISCES, and the bluer portion is passed by the dichroic in reflection onto the optical breadboard in the Top Box. Then it travels (in this picture starting from the left) through the periscope (Oli’s elegant design to give us nodding without the heavy Bayside Stages used for this purpose in LBTI and MagAO). Along this beampath we have the option to insert a calibration laser source used for pupil illumination tests. Next comes the input triplet lens and ADC (atmospheric dispersion compensator). Along this beampath some of the light is sent to the acquisition (ACQ) camera (a Basler) with a selectable beamsplitter wheel. Next are the fast-steering mirror (FSM) that we use to modulate the beam (modulator) and K-mirror (which adjusts for the parallactic angle), then we have a flip mirror which gives the option of either the visible-wavelength wavefront sensor (WFS) or the infrared WFS. Just before this flip mirror is a fairly new addition, a pupil imaging lens (with Lyot stop placed just before the FSM) can be inserted here and a pellicle to a ZWO camera to image the pupil. On this run we are primarily focusing on the visible WFS, the acquistion camera, and the pupil imager.
[Image description: An optical diagram of the Top Box shows optical beams and elements that pass and control the light in the wavefront sensor subsystems.]
Here is a pupil image Grant took last night with the ZWO camera in pupil imaging mode as the dome was closing, to help Oli size the Lyot stop correctly: The bright ring is the sky, the circular shadow is the secondary, supported by the spiders in black, and the white rectangle in the center is the last bit of the primary mirror that can see the dawn sky as the dome was closing.
[Image description: Blurry white ring on a black background. Inside the white ring are four dark diagonal lines making a cross, and a white elongated rectangle with a dark hole in the center.]
The Top Box is currently operated as follows. During initial alignment at the start of the run, a lot of optics must be adjusted manually (often by Oli; this run it was by Grant and Dan). Next we have the movement of remotely-adjustable motors, from filter wheels and the periscope to the modulator (FSM) speed and amplitude. While we have a gui design in progress, these are currently being operated using the original engineering guis of each of the individual COTS components, here is their control station:
[Image description: Photo of a computer screen with several guis for components by Thor Labs and Basler among others.]
The WFS in the Top Box and the ASM above the telescope work together in a closed feedback loop to flatten the wavefront. This is controlled by the AO software CACAO and CHAI currently being written and operated by Andrew, Amali, Eden, Jared, Olivier, Jacob, and Robin. Here are Amali and Andrew closing the loop on WFS noise when the dome is closed due to high winds:
[Image description: Amali sits in front of two monitors and a laptop. The monitors are full of guis, TMUX screens, and displays of the AO system and CACAO. The laptop has Andrew on Zoom.]
Now consider the redder portion of our wavefront. That passed through the dichroic in transmission and went into our science camera PISCES. The PISCES optical path inside the dewar has two cameras (narrow-field 26” f/23 and wide-field 100” f/5), a filter wheel (JHKs and narrow bands 1.113um, H2 2.122um, Br-g 2.166um, FeII 1.64u, and 1.2um), and a Hawaii-1 chip.
[Image description: On the left is a line drawing of the optical diagram of PISCES. On the right is a photo of PISCES mounted to the telescope, which is labeled with PISCES’ components.]
PISCES is operated from our fifth and final computer station in the control room:
[Image description: Photo of the computer screen for running PISCES control software, which consists of a ds9 display of a seeing-limited star at K-band, a terminal, the control gui, and the PDF operations manual.]
It’s 5am (about an hour before dawn) and looking at the weather, we don’t think the wind will clear up in the next hour, so we’re going to bed early. The song of the day is Chilly Winds by the Kingston Trio:
[Media description: Folk group “The Kingston Trio” sings “Chilly Winds” on a stage in the early 60s.]
Hello Extreme Wavefront friends, I’m back! Tonight was the start of our first MAPS run after the summer shutdown and it’s the usual packed control room, multi-tasking team, full moon, and beautiful mountaintop observatory!
[Image description: Gallery of photos showing the MMT Observatory at the top of Mount Hopkins, the telescope overlooking the valley, and the moon and clouds through the dome slit.]
MAPS is the MMT AO exoPlanet characterization System and is an ASM-based third-generation AO system with two pyramid wavefront sensors and a suite of science cameras. Our primary focus is on exoplanet science, although the broader diffraction-limited/enhanced-seeing MMT community will also benefit from the return of AO.
On this run we are starting with general system checkout and alignment, then focusing on AO software tasks such as offloading and pupil real-time alignment, as well as on-sky calibration of our interaction matrices.
It was a fun first night with Grant announcing “Field trip!” everytime we asked him and Dan to go up to the dome and adjust something in the Top Box.
By the end of the night we had nicely aligned PISCES and the pyramid pupils.
[Image description: Gallery of photos showing astro-engineers in the control room operating AO software or looking at the sunset; line drawing of telescope and camera optics; and photos of various guis showing starlight manipulated in various ways to show PSFs, pupil images, and pyramid pupils.]
For the blog rules, we’ll stick with the classic/basics: One post per night, one song of the day.
Tonight’s song of the day is a cover of the Cranberries’ Zombie by Bad Wolves:
[Media description: High-production-value music video of the group “Bad Wolves” performing the song “Zombie” as a cover and tribute to the original by the Cranberries.]
