The ins and outs of stellar occultations

The occultation of two stars in the Cancer constellation by the Moon, imaged at 04:56 and 05:21 GMT, respectively, on 21 January during a lunar eclipse.

The image on the left shows the star HIP 39869, located 5930 light years away, shortly before disappearing behind the Moon’s disc; and the image on the right shows the star HIP 39749, located 309 light years away, as it emerges from behind the Moon after its occultation.

These images were taken at ESA’s European Space Astronomy Centre near Madrid, Spain, with a Newtonian (reflecting) telescope CG8 with 20-cm aperture, and a Canon EOS550D camera.