NGC 281 (Pacman Nebula)
Characteristics:
Magnitude: 7.0 (open star cluster)
Size: about 35'
Distance: ?10,000 light years
RA: 0h 52m 48s
Dec: 56 degrees 37' 0"
Description:
NGC 281 is a star cluster associated
with nebulosity. The young, blue central stars are being formed
from the surrounding gas, which emits Ha light after being excited by
stellar
radiation. The nebulosity of this region is faint and can be best
appreciated in long exposure images such as this. There are
prominent Bok Globules in the central portion of this image, best seen
on this higher
resolution view that I took through the Takahashi FS102. The
nickname
"Pacman Nebula" derives from its appearence when viewed sideways
(although I prefer the above orientation).
Photographic
Details:
Date: September 10, 2004
Scope: Takahashi
Sky 90 at f4.5 with field flattener/focal reducer, on the G11 Losmandy
Mount.
Autoguider: SBIG STV with
e-finder.
Camera: SXV-H9
Filter: Astronomik
Ha filter (13 nm bandpass); Type II R, G, B filter set.
Exposures: Ha:(HaR:G:B).
20 x 5' for Ha (100
minutes total, unbinned); 5 x 4' each for R, G, and B (20 minutes total
for each color), all unbinned.
Conditions: Temperature 52 degrees F; above average
transparency; below average seeing as front was passing through; calm.
Post-processing: No darks,
flats, or bias frames used. Alignment done in ImagesPlus.
Sigma
combined using RC Sigma Reject Plug-in for MaximDL. Gradient
correction of color channels performed in ImagesPlus. DDP was
performed in ImagesPlus
(IP). Subsequent
levels and curves adjustments in Photoshop CS (16 bit format). Ha
was combined with RGB using the technique of Luminance
Corrected RGB.
Please
note: Graphics on this website
may not be reproduced without author permission.
Back to Nebulae
Home
