M81, M82, Integrated Flux Region (rollover)
Characteristics:
Magnitude: 6.9
Size: about 21' x 10'
Distance: 12 million light years
RA: 9h 55m 58s
Dec: 69 degrees 02' 43"
Description:
Place your mouse cursor over the above
image to see what Steve Mandel has termed the Integrated Flux
Nebula. This
region is located high above the galactic plane and is filled with
interstellar dust that reflects light from the billions of stars
shining in the Milky Way galaxy. The signal from the IFN is very
faint and difficult to process above the background noise. With a
long exposure and careful attention to good flats, it is possible to
bring out much of this region.
This
area is filled
with galaxies both large and small. M81 (the largest
galaxy just left of center) is a grand-design spiral galaxy
that was discovered by Johann Bode in 1774. Due to its
relatively large size and high surface brightness, it is an easy target
for visual observation through small aperture telescopes. M81
forms a galactic pair with M82 (just right of center), located only
150,000
light
years apart, and the two galaxies have influenced each other through a
close encounter occurring tens of millions of years ago. Closer examination
of
this image reveals a larger
companion galaxy just to the top of M81, referred to as Holmberg
IX. More information about M81
may be found here.
M82 (the smaller galaxy just right of
center)
is a companion to
M81 and was also discovered by Johann Bode in 1774. It has an
odd,
oblong shape that is thought to have arisen from gravitational
interaction with M81 millions of years ago. High resolution
color images of M82 show dramatic tendrils of red gas shooting from
the center of the galaxy.
Photographic Details:
Date: March 24, 2007
Scope: Takahashi
FSQ-106 on the G11 Losmandy
Mount.
Autoguider: ST402 with
e-finder.
Camera: STL11K.
Filters: Luminance,
R, G, B Type II
filter set (Astronomik).
Exposures:
L: 60 x 4'; R: 12 x 5'; G: 12 x 5'; B: 12 x 6'. Total
exposure duration 7.2 hours.
Conditions: Temperature 45 degrees at start of session;
above
average
transparency; fair seeing; calm. Imaging
performed at -20 degrees C throughout.
Post-processing: Calibrated,
aligned,
and combined in MaximDL, followed by DDP
in ImagesPlus (IP). Subsequent
levels and curves adjustments in Photoshop CS (16 bit format).
Please
note: Graphics on this website
may not be reproduced without author permission.
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