This picture was taken at a night in which extremely steady air was forcasted, so I took my 8" telescope to Schrick and exposed the chip for an overall 4 hours to the dark regions of Ursa Major. My target was a faint galaxy at the place where the back paw of the great bear is located. The object might have needed a bit more exposure, so on bright screens it may appear a bit noisy. However, I thought it was still worth to share...

The galaxy was discovered by William Herschel in 1787, it is about 27 million light years away from eath. What is interesting about NGC 3184 is that a star explosion discovered there in 1921 (SN1921B) was the first one given the name "supernova" by Fritz Zwicky, the famous Swiss astronomer. SN1921B was a type II supernova, which is triggered by the implosion of a massive star running out of lighter elements fuelling the stellar energy production.

But some of the extremely luminous star explosions (supernovae type Ia) follow an entriely different astrophysical process resulting in the very same luminosity according to astrophysical constants and principles. They play an extremely important role in measuring large scale distances in our universe, because they serve as "standard candles"; events with the same luminosity are perfect indicators for distance. Measurements of these supernovae do not only lead to a better knowledge about the size of our universe and its speed of expansion, but also to the amazing conclusion that this expansion accelerates. Currently there is no better way to explain this enigmatic effect by calling it the "dark energy"...