Comm2 Day 20: Off the telescope

Today we said goodbye to Alfio, Runa, Kate, and Alycia.

Here are Kate, Laird, Runa, Alfio, and Alycia hard at work in the Clay control room.

Then we removed the ASM, Clio, and the Nas from the telescope. It went well.

Laird and Juan lead the effort removing the NAS from the telescope.
The NAS is packaged up and lifted off with a crane.

Exhausted though we may be, we will miss this place after we’re gone.

The other day at sunrise, the sun on the clouds looked like a forest fire coming over the mountains

Comm2 Day 19: A spike of seeing

On our last night (last night) we had a spike of seeing up to 2” that gave our AO system a run for our money:

These spikes of seeing made us have to keep re-optimizing our AO parameters
Yuri Beletsky, Magellan Instrument Support Scientist, sent us this photo with the following note: “Tonight, while you were closing AO loops, I went outside and managed to capture some interesting view – while the night has been definitely not photometric, there is also quite strong airglow! You can easily see it as the green emission (due to atomic oxygen) on the image. On the center-right you can also see the bluish fuzzy ball of the Gegenschein.”
Stitching together a picture of the mountain and valley

Well, today we are taking everything off the telescope, it’s been a good run!

Quotes:
“But anyone could go in there and delete it!” – Laird, about doing the AO user’s manual on google docs
“Well, OK, but I could throw your computer off the catwalk.” – Jared
“We should do the manual in IRAF” – Laird
“Ah but then it would be a seeing-limited manual” – Alfio

Comm2 Day 17: Calibrating Clio while clouded out

We were clouded out tonight:

Tonight
Tonight
A few nights ago, for comparison
A few nights ago, for comparison

Also, a truck on the highway had an accident, which closed the highway, so the new turno couldn’t get here so the day crew had to also be the TO’s at night. We’ve been away from home for ~3 weeks and everyone is tired, but we stayed up all night in the control room working.

So, instead, I’ve been working on reducing my data, which includes determining various necessary calibrations for Clio. One important correction needed for high-contrast photometry is calibrating the linearity of the detector. To do this calibration, I took a set of measurements of increasing integration time, and determined the counts per itime:

Raw data that are not linear.
Raw data that are not linear.

I then fit various functional forms to the data until I found the best calibration of the linearity is a third-order polynomial that must be applied to pixels with counts above ~27,000 DN in the raw images, giving the result here:

The result of applying the linearity correction to the raw data.
The result of applying the linearity correction to the raw data. The linearity calibration must be applied to pixels with values above ~27,000 DN, and is not valid for pixels with values above ~45,000 DN for high-contrast photometry (there is margin up to ~52,000 DN for low-dynamic-range photometry).

Note that the data cannot be well-corrected above ~45,000–52,000 DN (depending on your tolerance for photometric error), and these values should be considered saturated in the raw images. I apply the calibration through an IDL function I wrote called “linearize_clio2.pro”. This is going onto the Clio observer’s manual.

Jared and I are working on astrometry, comparing Clio and VisAO measurements and exploiting our capabilities for boot-strapping: Clio has a wider field (up to ~30”) and can get a longer lever-arm on astrometric measurements, but VisAO has a finer pixel scale (~8mas) and a tighter PSF and can get precision astrometry on close companions. We are starting by verifying that we both get the same measurements for the locations of stars in the Trapezium cluster. To do this, I look at our Trapezium images and identify which star is which, then I compare the positions I measure to the positions measured by an earlier author. Here’s an illustration:

Measuring astrometry using Trapezium stars.  (Left) Trapezium as imaged at the LBT/PISCES in the IR a year or so ago by Laird.  (Right) Trapezium as imaged with MagAO/Clio here at LCO by me.
Measuring astrometry using Trapezium stars. (Left) Trapezium as imaged at the LBT/PISCES in the IR a year or so ago. (Right) Trapezium as imaged with MagAO/Clio here at LCO. Can you identify the stars in the picture on the right? (Ignore the black splotches which are negative star images, from the sky subtraction.)

I’ve measured the plate scale in both cameras and various filters, as well as the rotation offset to orient the images with north-up, which I’ve written in the IDL function “derot_clio.pro”. We’re working on a code repository for these data-reduction utilities that we’re calibrating on these commissioning runs.

In fact, Clio has two cameras, a wide and a narrow camera. Here is a comparison of the fields of view, including an illustration of the overlap:

The narrow field is shown within the wide field.
The narrow field (16” x 8”) is shown within the wide field (28” x 14”).

VisAO’s field of view is similar to Clio’s narrow camera along the short direction (8” by 8”).

Finally, I’ve been having a bit of fun experimenting with the APP coronagraphs that I want to use for following up GPI planets:

Fun with APP
Fun with APP

Well, it’s been a long night, good morning!

Comm2 Interlude: Announcing MagAO’s new Sagan Fellow

We are pleased to announce that our very own Jared Males (VisAO instrument scientist and software engineer) has been awarded a 3-year NASA Sagan Postdoctoral Fellowship by the NASA Exoplanet Science Institute to bring his PhD work to the next level.

Jared’s Sagan Fellowship is awarded to continue his work on MagAO, and use the system to look for exoplanets in the habitable zones of nearby stars.

MagAO’s and VisAO’s own Jared Males will begin his Sagan Fellowship next year.

During Jared’s fellowship, he will design and implement sophisticated techniques for imaging exoplanets in the habitable zone of nearby stars, using both MagAO/Clio, MagAO/VisAO, and LBT instrumentation. Read the press release here and here.

Jared will continue at the University of Arizona where he has access to the telescopes and instrumentation he needs for this work. Here is further information about Jared’s project:
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It is wonderful for the MagAO project to continue getting this recognition for the great strides our instrument is making in exoplanet research. Congratulations, Jared, and welcome to the Sagan Fellows family!

Comm2 Day 15: Continuous closed loop

Tonight we had great seeing and also fixed a hardware problem, allowing us to practice operating the AO system, VisAO, and Clio under ideal conditions. In fact, Laird ran the AO system, under Alfio’s careful tutelage, and the loop never spontaneously opened the whole night! This is thanks to Runa who replaced the switch BCU earlier in the evening:

Runa tests the fiber connection to the new switch BCU.

We miss Vanessa, who left yesterday, but now Alycia is here and she is able to help TJ run Clio on their targets, while I was running it with Laird on our targets. This is great and enabled me to get a bit of a break from observing at the beginning of the night, to work on other things. We are still engineering all our various modes — below is a photo of “waffle mode” that creates a cross pattern due to uncorrectable modes — and we are making great progress!

Strange objects in the sky…

One of the Clio modes we’ve been excited to test, for imaging faint companions, is the APP coronagraph. Here’s a pupil image of the APP with a bright star:

The APP illuminated by a bright star in pupil imaging mode — you can actually see the phase aberrations that make the dark hole on one side!

Our shipment of hard drives and hard hats finally arrived.

Our shipment finally arrived! Laird, Jared, and I show off our Arizona hard hats.

Vanessa had to leave because her skills are also in demand at the LBTI. But here’s one last picture of her and Jared, two graduates of Brookings High School, South Dakota, doing awesome work to bring the sharpest images in the darkest skies. Thanks for all your hard work, Vanessa!

Vanessa had a big impact on improving the performance of Clio. Here she is posing with Jared (whose impact is in developing and implementing VisAO) by Clio, VisAO, the WFS, and the Nas.

This is good work but exhausting. It’s nice to have something beautiful to see when we step out of the dome in the morning, to head down to a breakfast of fresh-squeezed orange juice and oatmeal and yogurt:

The colors at dawn to the east are just beautiful. When we’re walking down to breakfast at the end of the night, we have tried looking for the morning green flash — maybe we saw it!

Quotes:
“Call it Laird… dot tickle” (aka .tcl) — Katie to TJ, writing a TCL script to observe Laird’s target.
“Be motivated.” — Runa
“It’s like driving a rover on Mars.” — Alycia, watching TJ align Clio’s pupil, which is a very tricky business.
“It’s like a 6.5-meter space telescope!” –Laird, marveling at how well VisAO is working.