Comet Lulin is a non-periodic comet. It peaked in brightness and arrived at perigee for observers on Earth on February 24, 2009, at magnitude +5.
Lulin’s green colour comes from the gases that make up its Jupiter-sized atmosphere. Jets spewing from the comet’s nucleus contain cyanogen (CN; a poisonous gas found in many comets) and diatomic carbon (C2). Both substances glow green when illuminated by sunlight in the near-vacuum of space.
Date and place: February 28 2009; Pauleasca, Romania
Camera: Canon EOS 30D
Telescope: BORG 77ED
Exposure: 24 x 60 s
Aperture: 6.5
ISO: 800