Wednesday, July 10, 2013

Scorched astrojuly expositions

Literally. I got rid of my cooled camera Atik 314 (small chip size) and got regular Canon 450D that is not cooled, so its matrix gets hot during exposition. But camera itself is cool for astrophoto purposes :) ATM no bucks for large sensor astro camera.
Additionally the photo was shot during two July nights, when overnight temperature has not dropped below 18C, so the thermal noise is the hero here.
Anyway - the object, or region, has been selected as first light of 450D camera. Actually, it was not a first light - the camera has been bought second hand, and the shutter counter shows a little bit over 17,000 shots. But it is no big deal for Canon DSLR, the shutter life is about 100,000 cycles. The picture shows the region between North America nebula (NGC7000 - to the left), and Pelican nebula (IC5070 - top right image part) in constellation of Cygnus. Both nebulas are in fact a single cloud of ionized hydrogen that emits red light of 656nm wavelength. That's why almost the whole image is dominated by the red color.
The dark parts are the dust clouds placed between the nebulas and the Earth. This interstellar dust absorbs the light of stars and nebula behind, and also determines the nebula shape as we see it.
The distance to nebula is not precisely determined, however it probably is somewhere between 1600 and 1900 light years away.
The photo is stack of 100 exposures of 3 minutes each. It makes 6 hours of total exposure time at ISO800. The camera has been astro modded - the IR filter in the sensor has been replaced with Baader filter that allows H alpha light to pass to the chip. 

Clear skies!