COMET-CLUSTER CLOSE ENCOUNTER
This morning, February 3rd, Comet Garradd (C/2009 P1) sailed just 0.5 degrees from globular cluster M92 in Hercules. Italian astronomer Rolando Ligustri photographed the encounter using a remotely-controlled 106 mm telescope in New Mexico.
The full-sized image shows the comet’s fan-shaped dust tail, which roughly traces the comet’s orbit, and its pencil-thin gas tail, which points almost directly away from the sun due to the action of the solar wind.
Although the comet is now receding from the cluster, observers with wide-field telescopes can frame the pair in a single exposure for several mornings to come. They are located in the constellation Hercules, high overhead in northern hemisphere skies before sunrise. Sky and Telescope offers a sky map of the comet’s path. Observers with computerized GOTO telescopes can track the comet by plugging in orbital elements from the Minor Planet Center.
At the moment, Comet Garradd has an astronomical magnitude of +6.5, invisible to the naked eye but an easy target for backyard telescopes. Forecasters expect it to brighten by a factor of ~2 in the weeks ahead as the comet approaches Earth for a 1.3 AU close encounter in early March. This could be a good time to invest in a Comet Hunter.
