Object: Constellation: Coordinates: Size: Brightness:
NGC 7293 Aqr 22h30m / -2050' 16' x 28' 7.3mag

The beautiful planetary nebula NGC 7293 (Helix nebula) in the constellation Aquarius on August 1 and October 18, 2014. The expanding gas shell ejected from an old red giant star was discovered in 1824 by German astronomer Karl Ludwig Harding. It is 700 light-years from Earth and one of the closest planetary nebulae (source: Wikipedia).

Fourty-one 3 minute exposures at ISO 800 with no dark frame subtraction were stacked with Deep Sky Stacker (resulting in a 2 h 3 min exposure) and further processed in Photoshop. In Switzerland, the Helix nebula doesn't rise more than 23 degrees above the horizon. In addition, dew on the secondary mirror partly ruined several of the 41 frames used in this image.
Equipment: Canon EOS 450D Baader modified camera, TeleVue Paracorr Type II coma corrector, 16" f/4.5 "Ninja" dobsonian telescope riding on a dual-axis Tom Osypowski equatorial platform, Lacerta MGEN autoguider, Lacerta off axis system (field of view comparison: image of the moon with the same equipment).

Search chart for NGC 7293. Map © 2014 "The Mag-7 Star Atlas Project", www.siaris.net. Map is modified. The map can be downloaded here .