Month: November 2014

Clio is a good little camera. It has chip defects, cross-talk, and ghosts on bright stars, but what thermal-IR camera doesn’t? It also has a lot to offer and is very popular as seen by the telescope demand for MagAO/Clio. It has a deep enough well depth to take L-band images in the wide (coarse pixel) camera without saturating on the sky, and is sensitive enough to get good images in J-band, and can do low-resolution spectroscopy, imaging of faint companions, and it records some of the sharpest speckles you’ll ever ADI out thanks to our flat wavefronts being delivered by our AO system! Clio has so many modes — Narrow and Wide cameras, Imaging in 9 filters from 1-5 microns wavelength, Low-resolution spectroscopy across the L-band, Non-Redundant aperture Masking, and Coronagraphy (hopefully to be upgraded soon). We look at wide crowded fields, close-separation companions, disks, and more. Clio has cryogenic motors with 6 filter wheels holding a range of filters, aperture masks, pupil stops, and camera lenses for focal-plane and pupil-plane imaging modes. Clio sends focus commands to the AO system and offsetting commands to the telescope. We can control it with a GUI or scripts, including nods, integrations, subarrays, and filter changes. It has a heater and cooler with a PID controller to keep the chip cold. It is lightweight and shows no flexure, while holding its liquid nitrogen for 24+ hours. Thanks, Clio PI Phil Hinz!

I’ve been taking care of Clio this run, left with detailed instructions from Phil, T.J., and Vanessa, and help from Laird, Jared, and Alfio now too. For the last 2 nights, Arizona grad student Jordan Stone really put Clio through its paces, with me helping him in this effort. It was fun because we are learning more about how to best take L-band spectra with Clio. Here is an image showing what Jordan has been doing, with the help of the whole MagAO+Magellan team:

Because of the sky background being so bright and varying on a minutes-long timescale at L-band, and in order to average out the chip defects on Clio, we nod up and down the slit throughout the observations. Then Jordan will reduce the data by subtracting pairs of nods, determining the wavelength solution, and extracting the spectra. As we were walking up to the top tonight, Jared, Jordan, and I took a picture of ourselves in the mirror at the top. And I think we should have all shifted to the left and taken another picture, so that we could have subtracted the pair of images, because as you can see Jordan and Jared got hit by some “chip defects” and it looks like there is a wind-ghost messing up my hair:

We also tried to lock on a bright star at the start of the night, when the sky was still too bright for the telescope active optics to work, so instead Jared tried closing our 10-modes 0.1-gain loop for a long time, to allow the low-order modes to offload to the telescope. It was fun to try… and it worked! But it also took a while, and maybe we could have just waited for the sun to set… Anyway, we should try again sometime and suss out the parameter space!

Speaking of the sun setting, here are Jared and Kate — 2 of the VisAO PhDs — at sunset:

When we wake up, we can see the telescopes beckoning us from the top:

Here’s more of the dorms — really pretty and comfy:

And here are some more pretty pix from around the observatory:

Quotes:
Jared to Povilas: When can we work on the offloading and/or the DIMM?
Povilas: How about Monday?
Jared: Sounds great. What day is today? When is Monday?

(“Day” is a vestigial mode of time measurement based on solar cycles. It’s not applicable.)

20 days and counting.

So the last two or three nights we’ve been using MagAO at its geometric limits. By that I mean the various angles and rotations and cable contortions that the exciting science targets required. There was a conversation like this last night (accuracy not 100%):

Francois: “What’s the elevation limit?”

Jared: “Thirty degrees.”

Francois: “So I can go to thirty point zero zero zero zero zero zero one?”

Katie: “It’s not really a goal.”

Tonight Jordan flipped our system upside down about 25 times. It’s designed to do this, of course, but it makes for lots of fun keeping all of the precise alignment from primary mirror to secondary mirror, and down the PyWFS optics. Kate did a fantastic job keeping up with all of the camera lens re-alignments and axis changes on the pyramid. Still though, after a couple of nights of defending MagAO from marauding observers I feel a little like Captain Jack:

We forgot to post this last night. Here’s Francois Menard and Jos de Boer with the MagAO team.

And Jordan hard at work with Clio.

And our usual assortment of day-in-the-life pretty pictures.

I had some good metal picked out for tonight, but I think we need to just relax a little. Here you go.

That’s better.

Tonight started rather auspiciously with the best green flash that I’ve ever seen. Unfortunately, neither Jared nor I got a good picture, but here’s one I took during an  early commissioning run. Trust us – it was epic.

During twilight, Jared and Povilas added gaffers tape to the guider CCD. In the end though, they decided that the glint we saw yesterday during acquisition of new targets was probably the moon.  Still, it never hurts to have more baffling.

It was also discovered that when you immerse a roll of tape in liquid nitrogen, its adhesive properties are substantially altered. The details of how this experiment came to be conducted remain somewhat mysterious, and the result is awaiting independent verification.

I got to try my hand at operating the AO system today, which was fun for me and largely uneventful. The system runs so nicely these days (knock on wood), that I had lots of time to be mesmerized by turbulent patterns moving across the mirror at 200-1000Hz.

I learned that the main barrier to smooth AO operation is actually lack of real estate on the computer screen. So many GUIs have to be open at once that strategic placement is required, and everyone has a different opinion about where the “right” place for each one is. Here’s what I arrived at tonight with some help from Jared and Katie.

Note that there are lots of windows peeking out from behind. That’s so that I can get to them quickly when I need them.

I also decided that it was time for a promotion on the MagAO team. You see, everyone else has a nice mug with their name and role on the team monogramed on it. Here are Jared and Katie holding theirs.

Luckily, we have a nice label maker, and some blank mugs, so I was able to correct this egregious oversight.

Quote of the Day:

Francois, in reference to a newly discovered triple system (see pic): “Let’s see what color it is”

Jos, looking at the image in an orange/brown color table: “It’s a bit brown actually, but if you want I could make it blue”

My husband is home alone with our son this week, and the poor guy has food poisoning, so the song of the day is for my family. Thanks boys for letting me be here!

 

My duty here on this run is to give Jared and Katie a bit of a break, which includes taking over some of the blogging.

Tonight we started the night by swapping out the batteries in the wind monitor, which meant that we had to tilt the telescope over so that we could get to it. Jared and Katie have done it many times before, so they’re old pros now, and it was fun for me to climb up on the catwalk and look at the backside of the secondary up close.

We had a brief hiccup at the very start of the night because there was a power outage on the mountain during the day. We just had to restart our software, so it was a pretty minor setback.

Hector Canovas and Adam Hardy started off the night with a continuation of their program from yesterday, then we switched over at midnight to observers Francois Menard and Jos Deboer. Things went so smoothly that we had a little time to analyze our blog stats from the last month. Here are the results for the US, broken down by state:

This triggered an argument regarding whose family loves them best. I’d say it’s pretty well tied between Katie and Jared’s families, but as you can see, I clearly lost. Step it up Brutlags!

Otherwise, not much to report tonight from Las Campanas. Trust us, that’s a good thing!

I’m told that I have to pick a song with deep astrophysical meaning to go with my post. This probably dates me, but here goes…

We had an action packed night, with many more targets than we’ve been observing so far on this run. The AO system wasn’t on its best behaviour, but we have learned to recognize most of its bad moods quickly and we can usually slap it back into shape right away.

Kate Follette is here, ready to help take up some of the operations load. Our visiting observers tonight were Hector Canovas and Adam Hardy from Universidad de Valparaiso. Here’s a shot of the bleary eyed “aoistas” this morning right before we quit, minus Katie who’s behind the camera, and minus Kate who went to bed too early to get her picture took.

In Kate’s defense, she made it to the half-way point after 24 hours of travel from Tucson.

Most of the targets we looked at for our new friends Hector and Adam were faint and red. When we set up the system for such targets we need to have a good guess how many photons per second the pyramid wavefront sensor (PyWFS – following the obviously correct conventions of Guyon 2006) will get. This can be tricky because our PyWFS has a very wide and very red pass band, something like R+I. So if you use the R magnitude on an M5 star, you’ll set up to run slower and with fewer modes than you need too. It’s worse if you give us the V magnitude. So tonight I whipped up a set of synthetic color corrections, and compared them to our PyWFS’s own estimates.

UPDATE: A day later, we have investigated why the R band colors were weird in the first version of these plots. We are now using a self-consistent set of VRI magnitudes, from the USNO UCAC4 catalog, transformed from APASS gri (AB). I think we can now declare the MagAO WFS pass band done. I’ve updated the next two plots to the latest, most correct version.

Here’s a fun set of bookends on the night. We took flats at evening and at morning twilight. During this, you can see a really cool pattern on the PyWFS. You can also see the secondary mounting structure lit up by the sun. See the difference?

Here’s a just-after-dawn shot to the west, towards the Pacific Ocean.

Though you might think this was about the ASM supports being too reflective, the song of the day is for Veteran’s Day.