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Monday, March 11, 2013
The weather up here 65N hasn't been very cooperative. My latest image, the Rosette Nebula, has taken during four different nights, about an hour at the time, before the clouds rolled in. Images are shot at 20.02, 25.02, 07.03 and 08.03. 2013.
I shot just H-alpha channel, other two channels, S-II and O-III are from an older wide field image of the same target.
Image is in mapped colors from the emission of ionized elements, R=Sulfur, G=Hydrogen and B=Oxygen.
The Rosette Nebula (also known as Caldwell 49) is a large, circular H II region located near one end of a giant molecular cloud in the Monoceros. The open cluster NGC 2244(Caldwell 50) is closely associated with the nebulosity, the stars of the cluster having been formed from the nebula's matter. The cluster and nebula locates at a distance of about 5,200 light years from Earth. The diameter is about 130 light years.
The radiation from the young stars ionized the atoms in the nebula, causing them to emit light, typical to each element, producing the visible nebula. Stellar winds, radiation pressure, from a group of stars cause compression to the interstellar clouds, followed by star formation in the nebula. This star formation is currently still ongoing.
from narrowband channels
Image is in visual spectrum and dominated by the red light emitted by ionized Hydrogen, H-alpha. Blueish hues are from ionized Oxygen, O-III.
A wide field image
A wide field image of the Rosette Nebula in visual colors, taken with the Tokina AT-X 300mm f2.8 camera lens and the cooled astronomical camera, QHY9.
Blog post about the image with technical data:
A study about an apparent scale
Click for a large image!
Note. A moon size circle in the images as a scale. (Moon has an apparent size of 0.5 degrees, that's equal to 30 arc minutes)
Processing work flow:
Image acquisition, MaxiDL v5.07.
Stacked and calibrated in CCDStack2.
Levels, curves and color combine in PS CS3.
Optics, Meade LX200 GPS 12" @ f5
Guiding, SXV-AO, an active optics unit, and Lodestar guide camera 11Hz
Image Scale, ~0,8 arc-seconds/pixel
13 x 1200s exposures for the H-alpha, emission of ionized Hydrogen = 4h 20min.
Colors are taken from my older wide field image
A single unprocessed 1200 second frame of H-a emission
A single 20 min. frame, just calibrated and nonlinear stretched to visible.
Imaged with the QHY9 camera, Baader 7nm H-alpha filter and Meade LX200 12" telescope.