Author: Jared Males

After 13 straight days of nearly perfect cloudless photometric conditions, we woke up to this today.

So, of course, we decided to go on sky for the first time.

We haven’t completed all of our internal calibrations, but going on sky will let us see if they are valid so that we can complete them with confidence. Furthermore, there are many other things we can learn by looking at a real star, with a moving-pointing-guiding telescope. To do this, we had to pull off our calibration return optic (CRO), a.k.a. The Crow. We decided that tonight was the night at about 4pm. The LCO crew responded – Juan, Mauricio, and Pato sprang into action to help us pull the CRO and get the telescope ready. So by dinner, all we needed was a sunset.

After a quick chicken dinner, we just went up and closed the loop.

Ok. It was harder than that.

Thanks to everybody who helped make this happen. We’re just getting started, and there’s lots more to come. Stay tuned!

Some quotes from today:

Laird: “We didn’t come here to get Lucky. We came here to be good.”

Povilas: “We have a situation here, where you’re arguing both sides.”
Simone: “Yes. I’m trying to sound wise.”

Laird: “There had better not be any frisbee tonight.”

Katie: “We’ll never run out of cookies.” (seriously, there are a lot of cookies up here)

Sorry for the tardiness of this post. The internet was down on the mountain when the night shift went to bed this morning. The day was a struggle, but we finally got at least something working, and then did some testing through the night.

The issue was a feature in our pupil which Simone has dubbed the Viscacha.

We tried several things. One quick and dirty modification was to remove the field stop for the Pyramid. Simone and Enrico climbed into the NAS to do this – after first convincing Laird that this was a good idea.

The day shift ended with a somewhat working 200 mode interaction matrix. So the night shift did some closed loop testing.

Things are hopeful. With only 200 modes we have a fairly high Strehl ratio PSF. The problem is keeping it stable. These two videos, taken with the VisAO CCD 47 at 32 fps, show this.

Youtube noted that my image was shaky, and asked if I wanted to fix it. F*&!$^ you Google. Here’s the same data set, but keeping only the best 5% of the images (Lucky imaging style).

After breakfast Laird reduced this data by “shifting and adding”. Here’s what our images will look like soon:

To try to control the vibrations that even Google noticed we put the Clio rack on some foam pads. This improved the power spectrum, at least removing the ~2 Hz spike.

Quotes:

Simone: “Laird, take a seat. You want to take your seat. I think we need to remove the Pyramid . . . field stop.”

Tyson: “Why don’t you just say you’re a carnivore plus vegetables and cheese.”

Laird: “I thought you were trying to take the frisbee away.” (To Phil, after realizing that Phil was playing frisbee with grad students and the post-doc.)
Phil: “I was just trying to help them meet their 100 hours for the week.”

Simone, on the viscahcha in the PWFS pupil images:
“The viscacha again!”
“There is a clear viscacha.”
“It is not a dynamic viscacha, it is a static viscacha.”

Laird: “It looks like a viscacha that’s been run over by a car.”
Simone: “Yes, but it’s still a viscacha!”

Laird: “I’d really like a headless, tail-less viscacha.”

Our CRO is a very fast f/1 optic, and our ASM makes an f/16 beam. So motions of the CRO are amplified by a factor of 16 in our focal planes. We can see this on the VisAO CCD47 as a dancing image due to small mechanical vibrations of the telescope.

The MagAO project is adding a little bit to the vibrations of the telescope, mainly with two cooling pumps. One pump circulates glycol for our CCDs and the Shutter, and the other keeps Clio2 cold. With the 16x CRO amplification, we really see the impact of these pumps. We recorded 60 sec time series of the CCD47 operating at 32Hz in a 64×64 subarray mode. Here are the results:

With both pumps off:

With the Clio2 pump off, and the CCD pump on:

With the Clio2 pump on, and the CCD pump off:

We are actually very happy with the vibration performance of the system attached to Clay. Taking into account the factor of 16 for the CRO reflection, we expect to have only a few milli-arcsec of jitter when we observe actual stars. We have also taken measurements with our internal artificial star without the CRO and confirmed this. Good news, especially for VisAO.

Another experiment we conducted was having the PI bounce around the control room. He has a noticeable effect.

Happy Thanksgiving!  I am thankful for clear skies, low winds, and contactless continuous facesheets.

We are employing fine Italian craftsmanship to obtain the interaction matrices for our AO system, using the “penina” internal light source (an artifical star) and the CRO retro-reflector.  These are crucial calibrations for the feedback loop to create the desired shapes on the ASM.

Here’s a short video of today’s action:

Watching that, you’d swear Laird speaks fluent Italian. Maybe it’s just Optics.

There were a few issues having to do with the slaved actuators in the unilluminated part of the pupil, so we haven’t finished the interaction matrices yet — there’s more alignment that needs to be checked first.

We are looking carefully at the pupil to see if the CRO is aligned properly with the ASM.  So let’s have a look at the pupil.  The “lollipop” is the slot that was cut out to keep a crack in the ASM from spreading.  You can see it in the lower center of the ASM in each picture in this collage.  There is also bird poop on the tertiary — it’s the splotch in the upper right image, at about 8:00.  More on the pupil images tomorrow.

 

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Heard at LCO today:

“We have three telescope operators? Just for Clay?” -Laird
“No. Just for you!” -Povilas

“If you don’t know which way is which, we’ll just drill two holes!” – Pato

“It’s the bird poop.” – Laird
“So we use the bird poop fiducial?” – Phil
(a helpful bird, which might actually live in the dome, gave us a nice way to figure out which way is up in our images)

“Alfio has a segmentation fault?” – Jared
“It’s not me, it’s IDL!” – Alfio

“A pupil only a mother could love.” – Laird
“In Italy we say, Every cockroach is loved by its mother.” – Alfio
“All the cockroaches are loved by their various mothers.” – Kids

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There was no turkey today, but we tried to keep up some Thanksgiving traditions:

MagAO’s official food blogger (Derek) grabbed a shot of our turkey substitute:

We are all thankful for the 4-course meals, 3 times a day… as well as the plethora of snacks found in every building!

Our crew is getting kind of big. Todays new arrivals were: Phil Hinz, Simone Esposito, and Enrico Pinna.

This morning we finished balancing the telescope, and collimated it. We also installed our new wind meter directly under the ASM.

To prepare for moving the NAS, we officially took over the Clay control room.

The big task after lunch was to install the NAS. We reviewed the procedure with the whole crew.

We first had to wait for the Mike guider to finish coming off the telescope.

Installing the NAS went smoothly. We’ve done this once before, so it was a good chance to test the procedure we developed last time. In this video we are raising the NAS from the dome floor up to the Nasmyth platform.

Once we had the NAS installed, we attached the new and improved Anaconda for the first time.

We also did a live test of the “Snake Pit”, the box that holds the loop of the Anaconda as it coils under the NAS platform. Our current solution is really more of a sketch.

After getting the NAS mounted, we turned it over to Povilas to start testing the guider.

Finally, we opened the dome and pointed at some stars. This was the first time that real starlight bounced off our adaptive secondary mirror – First Light on the ASM! The fantastic result of the tests we did are that we can focus the ASM with the normal travel range of the vane ends (the structure that holds our ASM above the primary).

Here’s the scene in the Clay control room during our first nighttime operations:

Povilas was able to collimate the telescope, and obtain ~0.65 arcsec images on the guider. A big night!

Some random snippets of today’s conversations:

Povilas: “It worked. It doesn’t matter whether I approve.” (note: this has been added to the MagAO support agreement as rule #1).

Tyson: “You’re makin’ me nervous.”
Laird: “Well, you’re making me nervous.”

Laird: “Just as long as everybody remembers not to stick their whatevers in there.”

Alan: “If it clears, it clears.”

Derek: “My wide field lens is performing 2% better than the theoretical limit.”
Jared: “You’re wrong.”

Derek took a walk around Clay today:

While mounting the wind monitor, the primary mirror covers were open with the telescope at horizon. This was an opportunity to pose for souvenir photos in front of a 6.5 meter mirror.

Finally, we note that this is the 100th post to our blog. Thanks for reading!