Hi everyone! With the beautiful weather and amazing avocados for every meal, it’s good to be back on the mountain again!
Because MagAO is now open to the public (so to speak) and we’re executing a variety of programs, I’m learning about a wide range of science projects.
Of course, there’s the “run of the mill” high-contrast imaging with VisAO. See the ring around the star in the image? That’s not a disk of material around the star; it’s a sign of a beautiful AO image. With very high-quality correction, the star’s light in concentrated into the core of the star image, leaving a “dark hole” around the star. The better the correction, the deeper the hole. Outside the hole, at the “control radius,” is a ring of small uncorrectable residuals. They look really prominent here because of the stretch, but they’re actually incredibly faint. At the right edge of the picture is a faint reflection, or ghost, of the star; you can see how tight the core of the star image is and how very faint the ring is by comparison. As Laird put it, “We get better quality on our ghost than most people do on their images!”
Switching gears, we also took wide-field images taken of stars toward the “bulge” in the central regions of the Milky Way. After spending so much time taking really sensitive images of single star systems, I’d forgotten Clio could take images like the one below! Subo, Ping, and Jen are following up “microlensing” target hosts with these data. Microlensing is a sweet technique for indirectly detecting planets around other stars. The gravitational pull of a massive object like a star or planet can actually bend light passing by it, creating an effect similar to how a glass lens bends light that passes through it. An everyday magnifying glass uses this bending of light to magnify objects. In the same way, a “gravitational lens” can magnify objects behind it via the gravitational bending of light. So if a planet and star just happen to pass in front of a more distant star, they will briefly magnify the light of the distant star in a particular way that astronomers can use to measure the mass of the planet – pretty wild! High-resultion imaging helps to constrain the planet models, so we followed up several different planet candidates as part of this program.
AO was running very smoothly for most of the night tonight under Katie’s watchful eye (the screen saver went on several times because nothing needed adjusting for so long!). We also had our first guest AO operator tonight. Dave Osip stopped by for a while to check in, and we roped him into operating for a while. It’s a good sign for the usability of the system if we can start having guest operators – thanks to the AO team for all the user interface and hardware reliability improvements!
And, of course, I went wildlife watching. From the control room window at dawn I saw a couple vizzies hopping on the rocks below.
And I’ll leave you with a very serious analysis of the vastness of the universe in song form. Including, perhaps, a postulate on multiverse theory:
Today we saw snowflakes here at Magellan! Thankfully, the weather was beautiful without a cloud in the sky; the snowflakes were on Clio.
This is an image of a star. Although it looks distorted, this image is actually great. If our AO system is performing well, the image shape (the technical term is “point spread function”) will be very stable. Who says no two snowflakes are alike?
This image is using a technique called “non-redundant masking,” or NRM, to further improve the resolution of our telescope. With NRM, it’s possible to increase our already AO-enhanced resolution by another factor of ~2. This lets us see companion objects extremely close to their host stars, for example. However, nothing good comes for free; in order to achieve super-resolution, we have to throw away most of the light reaching our telescope (see image below). So this technique is only useful for very bright targets.
For a detailed explanation of the images below are showing, and of how to go from telescope pupils to images, see Katie’s previous post.
The beauty of the MagAO system is its simultaneous visible/infrared imaging. So while we were imaging with Clio, Kate was taking visible-light data of the same objects to study the properties of their circumstellar disks.
In other news, Laird, Jared, Kate, TJ, and I gave a Magellan virtual tour to a group of prospective U of A grad students over Skype. The intertubes were a bit clogged, so I’m not sure how well they could see us, but hopefully our enthusiasm for the project came through anyway!
Runa also gave a virtual tour, though perhaps a lower-stakes one…
Former Steward grad Derek Kopon sent us this neat pic today from Amsterdam:
And of course, I can’t forget Miss Viz…
And finally, I gave a shout out…
“I don’t ever remember focusing at MMT. Not even once.” –TJ, “I’ve never had a grad student who said that.” –Laird
“Geeze, when are you going to stop nodding??” –Kate
You might have noticed that our server redirected you to https. This will help ensure that MagAO continues to be a source of good, clean, family-friendly fun. Thanks to Paul Hart for helping Jared get a certificate set up.
Thanks to our loyal readers, Jared has found a new source of funding for Arizona’s various AO endeavors:
Alfio and Marco have been hard at work building bigger and better interaction matricies. By enabling or disabling rings of ASM actuators around the central obscuration, they are able to create more robust, higher quality calibrations. They create different sets of shapes (different “modal bases”) to apply to the mirror, based on which actuators are enabled. The new interaction matricies they’ve taken today have improved the VisAO image quality by ~20%! They also took a full suite of calibrations which will allow us to observe very faint targets.
Today we also moved the Clio solid nitrogen pump down to the basement, to reduce telescope vibrations. The optical alignment of the CRO is so sensitive that we can easily see a 1 micrometer (10^-6 meter) displacement. So we need to take as many sources of vibration off the telescope as we can; pumps are especially bad. The telescope staff routed a ~150ft hose from Clio to the pump’s new home in the basement.
We’re T -1 day from going on sky. The whole gang is hard at work finishing preparations to the AO system, VisAO, and Clio.
Tomorrow, two more team members will be arriving: TJ Rodigas and Kate Follette. Just in time for the big debut!
Now it’s time for me to follow Povilas’ lead…
“You drive me to caveats” — Povilas
“Now the entire blog is staged” — Katie (after Povilas admitted that he said that just to get on the blog. He loves us.)
“Nature throws thing at you that are not Kolmogorov. That’s a major caveat.” — Laird
“Maybe we should go back to the old interaction matrices. If the Strehl is too high, it might melt VisAO’s CCD” — Jared
“Cheese helps me to concentrate” — Marco
“Well… is the Clio pump on?” — Laird (asking completely sincerely!), blaming Clio for vibrations even after we stuck its pump down in the bowels of the telescope
“I have control over everything” — Alfio
“If you can’t focus a camera then you shouldn’t really be going on-sky with it” — Laird