NGC 7635 - Bubble Nebula
Canon 5D3 with Celestron's CGEM 1100HD. Taken in the Northwoods of Wisconsin with fair seeing and very dark skys. Used ISO 1600 and a stack of eight (using Deepskystacker). Each exposure was 10 minutes with a dark frame of the same time. Manual guiding was done using Celestron's Off-Axis Guider and Orion's 12.5mm illuminated reticle eyepiece. Hope to get more images in the future for greater stack number to reduce grain.
This emission nebula is about 11,000 light-years away and rather dim at Mag 10. Its size is about 15x8 arc-mins (long lenth is 1/2 size of moon). The bright star off-center of the bubble is causing all the action (bubble due to solar winds, red emission due to its radiation). This star is 15 times as massive as the sun.
The reds are H II emissions and these occur very close to the cameras' IR filter so are reduced by a factor of 6 or so (no, I am not going to remove the filter on the 5D3!). These IR filters are unfortunate for astrophotography since the best images are H II regions (but OTOH it stops us from seeing too much of people we photograph!). I think Canin is going to be making the 60A, "A" for astronomy, that has the filter removed.
NGC 7635 - Bubble Nebula
Canon 5D3 with Celestron's CGEM 1100HD. Taken in the Northwoods of Wisconsin with fair seeing and very dark skys. Used ISO 1600 and a stack of eight (using Deepskystacker). Each exposure was 10 minutes with a dark frame of the same time. Manual guiding was done using Celestron's Off-Axis Guider and Orion's 12.5mm illuminated reticle eyepiece. Hope to get more images in the future for greater stack number to reduce grain.
This emission nebula is about 11,000 light-years away and rather dim at Mag 10. Its size is about 15x8 arc-mins (long lenth is 1/2 size of moon). The bright star off-center of the bubble is causing all the action (bubble due to solar winds, red emission due to its radiation). This star is 15 times as massive as the sun.
The reds are H II emissions and these occur very close to the cameras' IR filter so are reduced by a factor of 6 or so (no, I am not going to remove the filter on the 5D3!). These IR filters are unfortunate for astrophotography since the best images are H II regions (but OTOH it stops us from seeing too much of people we photograph!). I think Canin is going to be making the 60A, "A" for astronomy, that has the filter removed.