UPDATE: 6/17/10 – Paper published in Nature magazine gets worldwide scientific attention.
UPDATE: 10/23/09 – Sky & Telescope Magazine picked up this story and featured it in their online magazine!! Check it out – http://www.skyandtelescope.com/news/65538577.html
Last week I traveled to Mexico, specifically to Mexico’s Observatorio Astronomica Nacional’s San Pedro Mountain Observatory in North Baja California state, located 9,100′ (2790 m) high in the San Pedro Martir National Park. Some folks at the MIT Planetary?Astronomy?Lab had enlisted me and four fellow members the Amateur Telescope Makers of Boston, to carry specially designed CCD cameras to remote sites across both hemispheres to capture data on the occultation of an approximately 500km diameter Kuiper Belt Object, also called a Trans-Neptunian Object. The professional-amateur collaboration ?has worked well in the past for organizations like the American Astronomical Society, the Astronomical Society of the Pacific, the American Association of Variable Star Observers, and it proved to work well for MIT in this investigation.
We got right to work installing the camera on the telescope and testing it out in the daylight. We had a little trouble with the GPS unit but were able to get it stable enough for the night’s work.
MY FIRST OCCULTATION EVENT
We were fortunate that timing was perfect for a practice run on the first night. The target was (762) Pulcova, a main-belt asteroid discovered in 1913 by Grigory Neujmin and named after the Pulcova Observatory near Saint Petersburg Russia. Pulcova is 137 km in diameter and dark colored. It’s especially significant because in 2000?astronomers?at?the?Canada-France-Hawaii Telescope in Hawaii discovered a small, 15km moon orbiting Pulcova?about?800km away. This was one of the first asteroid moons to be identified. Pulcova was to occult TYCO?2314-01655-1, a 12.2 magnitude star in Triangulum.
The telescope slewed and found our target star without trouble. I’d never operated at such a large scope so this was a special treat. As Dr. Michel calibrated the finder and guide scope, I switched on the camera and GPS timer. And there they were, both the target star and Pulcova.
ON TO THE KBO
Now on to our ‘real’ target, for the next night, or rather early morning, ‘our’ KBO would?occult?a magnitude 13.2 star, and this is what we were really here for.
We checked late occultation path predictions and weren’t sure whether we were going to see what we came here?for. The path had been revised to be about 1300km south of us but the certainty of the prediction was the reason we were here, because when combined with other observation reports, a negative sighting can help to define one dimension of the KBO. Dr. Michel and I met at 1:30am (08:30 UT) and drove to the?observatory.
Our first goal was to attempt a long exposure to capture the KBO before the occultation started. Dr. Michel adjusted the telescope and focus, then engaged the auto-guiding system. ?We took one, five minute exposure?but it was not visible.?I set the automated system to take one, 0.5 second exposure every 1.5 seconds starting at 10:07UT.
I COULDN’T HELP BUT LOOK UP
I again set up my camera on a tripod while the shots were being triggered by the GPS?receiver. While Dr. Michel monitored the telescope tracking from inside the warm control room, I set a pocket timer to 5 minutes and during each interval I would go outside the observatory and take in the beautiful night sky.
In all, we took over 2,000 images of the target star grouping between 10:07 and 10:56UT, and then 100 bias shots, then 30 flats. We submitted our data and are excitedly awaiting reports from the researchers at MIT.
BACK TO ENSENADA
Our ride back to Ensenada was uneventful, and I’m pretty sure I slept for part of the way.
Once we arrived on campus Dr. Michel showed me around the almost-new facility of the Observatorio Astron?mico Nacional. They have a beautiful facility that I look forward to visiting again.
My very sincere thanks go to Dr. Raul Michel and the staff at San Pedro Martir Observatory as well as the supporting staff at the National Autonomous University of Mexico in Ensenada.
Muchas gracias por la hospitalidad brindada durante mi visita al Observatorio Astron?mico Nacional. Tuve una estancia muy buena y la comida y los telescopios se apenas a la derecha. Espero volver a SPM en otro momento.