Object: Constellation: Coordinates: Size: Brightness:
Messier 1
(= NGC 1951)
Tau 05h35m / +2201' 6' x 4' 8.4mag

The supernova remnant Messier 1 (Crab nebula, NGC 1951) in the constellation Taurus on October 26 / 27, 2014. Messier 1 is 6500 light years from Earth. It is the result of a supernova explosion which was observed by Chinese astronomers in 1054 (and, of course, by thousands of people in the northern hemisphere). The "guest star" was visible during daylight by the naked eye for three weeks.

The gaseous remains of the star were independently discovered by John Bevis in 1731 and Charles Messier in 1758. British astronomer William Parsons, 3rd Earl of Rosse, sketched Messier 1 in 1844, using a 36-inch telescope. The drawing of the nebula resembled a crab, which led to todays designation "Crab nebula". At the center of the nebula lies the Crab Pulsar (see below), a neutron star 30 km across rotating 30 times per second (Sources: Wikipedia, Burnham's Celestial Handbook).

Twenty-four 3 minute exposures at ISO 800 with no dark frame subtraction were stacked with Deep Sky Stacker (resulting in a 1 h 12 min exposure) and further processed in Photoshop.
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).

Close-up of Messier 1 and its neutron star PSR B0531+21 (crop of the image above, darkened).

Search chart for Messier 1. Map © 2015 "The Mag-7 Star Atlas Project", www.siaris.net. Map is modified. The map can be downloaded here .