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Time Travel Research Center
© 2005 Cetin BAL - GSM: +90 05366063183 -
Turkey / Denizli
The Rosette Nebula (NGC 2237-2239)
Characteristics:
Magnitude: 4.8 (for NGC 2244 star cluster in center)
Size: 80' x 60'
Distance: 5500 light years
RA: 6h 31m
Dec: 4 degrees 57' 00"
Description:
The Rosette Nebula is a winter showpiece for astrophotographers, as well as
for visual observers at low power. This large emission nebula is located in
Monoceros and can be seen in dark locations with the naked eye, especially
if viewed through a UHC filter held up to the sky. The nebula actually
consists of several sections (NGC 2237-2239), with a central ladder like
star formation known as NGC 2244. The central stars are young and newly-formed,
and their radiation is responsible for excitation of hydrogen atoms within
the nebula itself, which in turn emit light in the red. This is a deep, 4
hour exposure in hydrogen alpha light, combined with 100 minutes of color
data, which reveals a great deal of faint nebulosity on the periphery of the
Rosette, as well as filaments that extend well outside of this field of view.
I compared this image to one taken by the POSS 50 years ago and detected
several stars exhibiting proper motion.
Photographic Details:
Date: November 23, 2007 (Ha data) and December 8, 2007 (RGB data).
Scope: Takahashi FSQ106 at f5 on the Takahashi NJP Mount.
Autoguider: SBIG ST-402 with e-finder.
Camera: STL11K -20C.
Filters: Baader 7nm Ha filter (50mm unmounted); Astronomik RGB filter set.
Exposures: Ha- 12 x 20'; R- 5 x 6'; G- 6 x
5'; B- 5 x 8'. Total exposure 5.7 hours.
Conditions: Temperature varied between
20-30 degrees F over the course of the night on 12/8/07 (focusing every 1
hour).
Post-processing: This is an HaRGB composite. Calibrated, aligned, and
Sigma Clip combined in Maxim, followed by DDP in ImagesPlus (IP). Further
processing in Photoshop CS (16 bit format).
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