This is the rosette nebula (NGC 2237,8). A beautiful rosy coloured object, with filaments, dark lanes, dusty blobs, and meandering, snaking streamers all lit up by a bright cluster of stars at the centre of the central chasm (NGC 2239,2244). It looks like a tunnel, as I am trying to imagine it in three dimensions. I see one of the stars, the bright one at the centre I used to guide the telescope, is slightly yellower than the others. This object is depending on what instrument you are using, annoyingly or satisfyingly large. By annoyingly large, I mean that it won’t come close to fitting into my camera field on the big scope, even with a field-widening lens on it. If you are slightly more impressed with the sharpness of the stars on this pic, it is because I had to mosaic 4 pictures together. As is usual, I don’t want to spend all night on the scope and so I just took one single 1 minute exposure on each quarter of this final image, and merged them all, manually at home. Just 1 minute exposure - that’s nothing, for such a wonderful amount of detail. Perhaps I should do a 3x3 or 4x4 mosaic to get even more of it in, but the astronomer has precious little time. Here is a rough calculation of the time astrophotographers have to work. 60% it is too light because of twilight or the sun is up (depends on latitude). 50% of the time the moon is up, making it too light. 50% of the time it is inconvenient to get to the observatory (plus we need to sleep). 70% of the time it is too cloudy (depends on how much cloud your country loves). 50% of the time your equipment doesn’t work or doesn’t work properly. That’s 40% x 50% x 50% x 30% x 50% = 1½%.
Thursday, 7 April 2011
Sigur Rós
This is the rosette nebula (NGC 2237,8). A beautiful rosy coloured object, with filaments, dark lanes, dusty blobs, and meandering, snaking streamers all lit up by a bright cluster of stars at the centre of the central chasm (NGC 2239,2244). It looks like a tunnel, as I am trying to imagine it in three dimensions. I see one of the stars, the bright one at the centre I used to guide the telescope, is slightly yellower than the others. This object is depending on what instrument you are using, annoyingly or satisfyingly large. By annoyingly large, I mean that it won’t come close to fitting into my camera field on the big scope, even with a field-widening lens on it. If you are slightly more impressed with the sharpness of the stars on this pic, it is because I had to mosaic 4 pictures together. As is usual, I don’t want to spend all night on the scope and so I just took one single 1 minute exposure on each quarter of this final image, and merged them all, manually at home. Just 1 minute exposure - that’s nothing, for such a wonderful amount of detail. Perhaps I should do a 3x3 or 4x4 mosaic to get even more of it in, but the astronomer has precious little time. Here is a rough calculation of the time astrophotographers have to work. 60% it is too light because of twilight or the sun is up (depends on latitude). 50% of the time the moon is up, making it too light. 50% of the time it is inconvenient to get to the observatory (plus we need to sleep). 70% of the time it is too cloudy (depends on how much cloud your country loves). 50% of the time your equipment doesn’t work or doesn’t work properly. That’s 40% x 50% x 50% x 30% x 50% = 1½%.
No comments:
Post a Comment