Unique astronomical event captured by U of M team

Last week, a team of amateur astronomers at the Glenlea Astronomical Observatory south of Winnipeg managed to capture a video image of an asteroid passing in front of a star. The astronomical event, called an occultation, is rare and difficult to observe, and the astronomers’ ability to observe it required a great deal of skill — so much skill that an international astronomy magazine profiled their work online.

Jennifer West is an instructor and Ian Cameron is planetarium supervisor with the department of physics and astronomy, Faculty of Science; Jay Anderson is editor-in-chief of the Journal of the Royal Astronomical Society of Canada and former instructor in astronomy at the U of M. The trio captured an excellent video of the asteroid Juno as it eclipsed the 7th-magnitude star SAO 117176 on November 19, 2014.

Juno is a one of the largest asteroids discovered by astronomers, with an average diameter of about 250 km. It orbits the Sun between Mars and Jupiter. The star is in the constellation Hydra, low in the southeastern night sky.

Manitoba was the only location on Earth with a clear sky where such an observation was possible. The team recorded the event using the U of M’s observatory’s 16-inch telescope and an Apogee AP47 CCD camera. The entire occultation lasted only about 20 seconds.

Sky and Telescope magazine noted: “Precise timing of the disappearance and reappearance of the star from multiple locations help astronomers build an accurate shape profile of the asteroid. And in rare cases, tiny moons of these larger asteroids have been discovered during occultations when the star unexpectedly winked out twice.”

*Occultation occurs at :34 mark of video.