An Update on Robo-AO

Last week just about everything here on Palomar Skies was related to PALM-3000, the new upgrade to the Hale Telescope's adaptive-optics system. Readers of this blog may remember that PALM-3000 isn't the only game in town when it comes to adaptive optics on Palomar.

The other program that is pushing the envelope is Robo-AO, a laser-guide star adaptive-optics system for Palomar's automated 60-inch telescope. The Robo-AO team was on the mountain last week and Christoph Baranec, Principal Investigator for the program snapped these false-colors photos of their ultraviolet laser propagating out of the dome.


The laser makes use of Rayleigh scattering, which will ultimately help their system to correct for turbulence in the lower 10 kilometers (~6 miles) of the atmosphere. This will allow the 60-inch telescope to take very sharp images of a wide variety of astronomical objects.

(See that sort of blurry star trail, just to the right of the laser beam? That is the globular star cluster known as Omega Centauri.)

The Robo-AO program is still in the engineering phase. Expect a full science demonstration observing run to take place later this year.

Robo-AO is Moving Forward

The Robo-AO team is back on Palomar for another week of testing new equipment on our 60-inch telescope. I have blogged about Robo-AO before, but for those who don't know, the Robo-AO system will soon be the world’s first laser-guide star adaptive-optics system working on a robotic telescope. When it is in operation it should deliver ultra-sharp imaging for up to hundreds of targets per night.

The system began as a fully-working testbed has been operating at Caltech in the Cahill Center for Astronomy and Astrophysics basement for several months. Starting last fall the team has been given some engineering time every few months to gradually bring the system up and on the Palomar 60-inch telescope.

In September of last year they had their first propagation of their ultraviolet (UV) laser into the sky as a guide star for adaptive optics. Earlier this year they were able to successfully have the beam sent up the telescope's axis and measure the return.


The team is back at Palomar this week for the installation of new equipment and further testing.

In the image above notice the new electronics rack mounted on the telescope at right. In the center is part of their new adaptive-optics instrument and the black box at left is the laser.

Their are still additional components to integrate into the system, but it is expected that start of the science demonstration period will commence in late summer.

Robo-AO in Action

I am hearing that the Robo-AO team has had a good week of testing here on the Palomar 60-inch telescope.

Their ultraviolet (UV) laser is mounted on the south side of the telescope. One of the chief issues for the week was the installation and testing of their periscope which transfers the laser beam from being just offset from where the telescope is pointing to being on axis with the telescope.

If you look at the photo below you can see the location of the laser, which is located in the black box just under the telescope on the right side. From this position the laser will propagate to the upper left where their periscope assembly is located. You can see that as the black end of the telescope with something hanging off of it.


The second photo shows the whole set up from a different perspective. Note that the cover to the laser has been removed. Click on the image to get a better look at its innards.

Photo by Christoph Baranec

The third photo shows the periscope assembly from a different vantage point. Christoph Baranec (Robo-AO's principal investigator) can be seen adjusting a mirror. In this image the UV laser is on. UV light is invisible, but still potentially damaging so you'll notice that Christoph is wearing a face shield to protect his eyes (I was wearing one too when I took this photo). Also notice that the mirror on the center axis of the telescope is fluorescing due to the UV light shining on it.

Saving the best for last, this final photo shows the top of the telescope. It was taken with a camera that records UV and visible light, so it reveals both the telescope and the normally invisible UV laser beam.

Photo by Christoph Baranec

The team has also been evaluating any flexure in the telescope and laser pointing to better ensure better results in the future.

Stay tuned for more on the Robo-AO program. Their next observing run will be in March.

Robo-AO Returns to Palomar

This week the Robo-AO team is back on Palomar for some tests of their laser-guide star adaptive optics system for our 60-inch telescope.

I will post some updates and shots of the laser in action over the next week or so, but here is a shot looking at the back end of the telescope showing some of the equipment that is in use for the project:

More Robo-AO Laser Pictures

As promised here are a couple of photos of the recent laser tests on the Palomar 60-inch telescope for the Robo-AO project.

The first picture show a close-up view that shows a portion of the 60-inch telescope at left and a view of the UV laser and its beam propagating upward.


The second shot, taken just outside the dome, shows the laser beam against the star field.

Finally, we have a wider view showing the laser beam propagating upward into a cloudy sky.

Thanks go out to Christoph Baranec and the Robo-AO team for letting me post these shots. For more on the project be sure to check out my previous post and the Robo-AO website.

Palomar Owl

Last month, just before sunrise after the first successful laser test for the 60-inch telescope's Robo-AO system, Christoph Baranec (Robo-AO's P.I.) spied and photographed this owl:

We do not know if this is the same owl who had been perching on our all-sky camera, but we are checking into it. Alas, a technical issue has delayed out all-sky camera from going public just yet.

We will let you know as soon as the all-sky camera is up for public display. In the meantime, enjoy this full-resolution look at the owl.


By the way, Christoph also took some great shots of the Robo-AO laser in action. Look for those to be posted here soon.

Robo-AO Comes to Palomar

Robo-AO, a new laser-guide star adaptive optics system for Palomar's 60-inch telescope, had a successful test of their laser last weekend.

False-color composite image of the Robo-AO laser & 60-inch telescope

Adaptive optics is a technique that allows ground-based telescopes to remove the blurring affects caused by Earth's atmosphere. The adaptive optics system uses a star as a calibration source and then deforms a small mirror to correct for distortions caused by the atmosphere. The corrections are made faster than the atmosphere can change -- often thousands of times per second.

By projecting a laser into the sky astronomers can expand this technique to cover a larger fraction of the sky.

Here is the 60-inch telescope last Sunday night just after the dome was opened.

The 12-Watt laser is in the black box mounted on the south side of the telescope (between the arms of the mount).

Here is the view with the lights turned off and the laser turned on:

Notice that you can't see the laser (but you can see where it is making a part of the telescope's insulation fluoresce!). Being invisible is one of the chief advantages for the laser.

The light that the laser emits is invisible ultraviolet light. Because you can't see the laser light this system requires no human spotters to be staged outside looking for air planes. All laser-guide star systems (like the one that has been used on the 200-inch Hale Telescope) that make use of visible light are required by the FAA to have spotters. Even hand-held laser pointers can be a danger to aircraft.

The Robo-AO system does not require spotters, which is perfect because the telescope normally operates in robotic mode without any people being present.

As the UV laser shines up toward its astronomical target astronomers make use of something known as Rayleigh scattering. The UV light scatters off of molecules in the air, giving a return signal that tells the deformable mirror in the adaptive optics system how to correct for atmospheric turbulence.

The Robo-AO system will be the first robotic laser-guide star adaptive optics system, delivering high-angular-resolution observing in the visible for up to hundreds of targets per night. This will enable the exploration of science parameter spaces inaccessible to large diameter telescope adaptive optics systems. A fully-working testbed has been operating at Caltech in the Cahill Center for Astronomy and Astrophysics basement for several months, and the system is expected to start its science demonstration period in early 2011 at Palomar Observatory's 60-inch telescope.

From there the Robo-AO system will be available as a relatively affordable and portable option for to 1-3 meter class telescopes around the world.

The Robo-AO project is a collaboration between Caltech Optical Observatories and the Inter-University Centre for Astronomy and Astrophysics and is partially funded by the National Science Foundation.