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Sadr (Gamma Cygni) is at the center of the "northern Cross", the Cygnus constellation. Around this star there is one of the more intricate regions concerning the emission nebula. The main nebula is IC 1318, but in thruth it is made of at leas a dozen of nebulas. Inside are present a lot of dark nebulas and Bok globules. The Crescent nebula (NGC 6888) is at the south-west corner and resemble a crescent Moon. In the northern region other nebulas are present such as the Hourglass.
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Optics | Schmidt
camera 400/300/615 (Zen optics) |
Focal Lenght | 615 mm |
Focal Ratio | f/2,0 |
Exposure Time | Total 28
hours. Mosaic of 6 frames. 338 frames of 5 min
each. |
CCD | A camera with Kaf-6303e |
Sensor | Kaf-6303e
class 1 |
Filters | H-alpha
6nm
Astronomik, selected for f/2 |
Chip
temperature |
-20
°C |
Location | Tradate
(VA,
in Pianura
Padana, Italy) at 300m height |
Date and time of exposure start | 6 full nights: 19, 24, 26, 27, 28, 29 july 2007 |
Mount | Astrosystems
fork
mount |
Tracking | Webcam
Vesta
Pro B/W on a 120mm f/13 refractor reduced at f/5 |
Temperature and humidity | T=between
20
and 28 °C, RH=between 40 and 70% |
Sky brightness at zenith (with SQM-L) | 18.5 - 19.0 mag/arcsec^2 |
Notes | |
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