| Target: |
B33, dark nebula. Also known as the Horsehead Nebula. Narrowband image (H-alpha). |
Date: | 11.2.2005 |
| Time: | 20:57 .. 21:44 | ||
| Location: | Vantaa, Finland | ||
| Conditions: | Naked eye limit magnitude ~3.5. Target was low; alt 21° ... 17°. Temp -4°C, windy. | ||
| Telescope: | N150 f5 (GSO) | Mount: | GEM w RA stepper motor (Sky-View) |
| Camera: | Art-429 (beta). TEC
off. Hi-res interlaced mode. (1x1) |
Filters: | Astronomik Profi H-alpha CCD 000418 |
| Exposure: | 9 min (27 x 20s), dark frame (70 x 20s). Unguided. | ||
| Processing: | Not much. Levels etc. Reduced final size to 75% and squared pixels. Final unsharp mask. | ||
| Images: |
 full resolution image displayed |
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| Notes: |
This was my first time use of an emission line filter
and the 3rd target for my new Art-429 (beta) CCD camera. I planned of taking usable exposures of this target to a total of 1 hour but I ended up just with 9 minutes. It is a very short exposure considering the light loss in an emission line filter. Reason for not getting enough exposures was a misalignment of mount's worm gear that caused untolerable RA jitter on the images. However I managed to get a reasonably recognisable image of the target with just 9 minutes of light. |
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