Sh 2-197 A galaxy not emission nebula

SH2-197 is a very unusual entry in the Sharpless catalog of Nebula. It
was compiled in 1959 from the Palomar Observatory Sky Survey plates.
#197 fooled Sharpless into thinking it was an emission nebula. In 1968
Paolo Maffei looking for IR sources discovered it was really a galaxy so
obscured by dust it is only faintly visible in visible light. I see no
hint of it in my blue filtered data, it is weak in green light and
stronger in red though still quite weak. Sharpless can be excused for
his error on account that such galaxies weren't even dreamed of a the
time he compiled his catalog. Also its location, just below the Heart
and Soul emission nebula's would strongly favor it being a bit of
related nebulosity. Thanks to Maffei's discovery it is now known as
Maffei 2. Maffei 1 I posted a while back is also incorrectly listed in
the Sharpless catalog as SH2-191.

WISE, the very deep IR survey satellite took a great image of the Heart
and Soul Nebula that shows both Maffei 1 and 2 at the very bottom.
http://www.nasa.gov/mission_pages/WI...e20100524.html
Maffei 2 is seen at the very bottom just left of center. In the full
size image it is seen to be a nice barred spiral with a drawn out arm.
Likely it would have made Arp's list had it not been hidden from earthly
eyes. To the right beyond a pair of "blue" stars is Maffei 1 which is
very "blue" in the false color image. It has to be false color since
all of the light is far too red for our eyes to see even if it could get
through our atmosphere. The WISE image caption makes no mention of
these galaxies which I find strange.

The pair is thought to be about 10 million light-years distant and in
the constellation of Cassiopeia. Due to the highly variable obscuring
dust and gas in our galaxy what visible light that gets through results
in a very distorted image. I've placed the WISE image at the same
orientation and image scale to the right of my image. Some of the stars
can be identified in both images which cover the same region of the sky.
Some of the bright regions at either end of the bar can be identified
in my image, especially the "hook" going up from the bottom of the bar.
A hint of the drawn out arm is visible below the "hook" region. To
see it at these wavelengths Wise was cooled to within a 8ºK of absolute
zero by a block of frozen hydrogen. The satellite was decommissioned
after the last of the hydrogen was gone.

My fall weather created havoc trying to get this image. I tried on many
nights but only three were usable for the luminance channel and two for
the color channels. Still I managed 12 luminance images and 4 each for
each color. I could have used more.

In processing I removed most of the nebulosity from the Heart and Soul
Nebulae as they detracted greatly from even seeing Maffei 2. This is
one tough object!

14" LX200R @ f/10, L=12x10' RGB=4x10', STL-11000XM, Paramount ME

Rick
--
Prefix is correct. Domain is arvig dot net

Most interesting post Rick.
This galaxy could be worth a try with an IR-pass filter. I own such a
filter, but only in 1,25"...

Stefan

"Rick Johnson" schrieb im Newsbeitrag
.com...

SH2-197 is a very unusual entry in the Sharpless catalog of Nebula. It
was compiled in 1959 from the Palomar Observatory Sky Survey plates.
#197 fooled Sharpless into thinking it was an emission nebula. In 1968
Paolo Maffei looking for IR sources discovered it was really a galaxy so
obscured by dust it is only faintly visible in visible light. I see no
hint of it in my blue filtered data, it is weak in green light and
stronger in red though still quite weak. Sharpless can be excused for
his error on account that such galaxies weren't even dreamed of a the
time he compiled his catalog. Also its location, just below the Heart
and Soul emission nebula's would strongly favor it being a bit of
related nebulosity. Thanks to Maffei's discovery it is now known as
Maffei 2. Maffei 1 I posted a while back is also incorrectly listed in
the Sharpless catalog as SH2-191.

WISE, the very deep IR survey satellite took a great image of the Heart
and Soul Nebula that shows both Maffei 1 and 2 at the very bottom.
http://www.nasa.gov/mission_pages/WI...e20100524.html
Maffei 2 is seen at the very bottom just left of center. In the full
size image it is seen to be a nice barred spiral with a drawn out arm.
Likely it would have made Arp's list had it not been hidden from earthly
eyes. To the right beyond a pair of "blue" stars is Maffei 1 which is
very "blue" in the false color image. It has to be false color since
all of the light is far too red for our eyes to see even if it could get
through our atmosphere. The WISE image caption makes no mention of
these galaxies which I find strange.

The pair is thought to be about 10 million light-years distant and in
the constellation of Cassiopeia. Due to the highly variable obscuring
dust and gas in our galaxy what visible light that gets through results
in a very distorted image. I've placed the WISE image at the same
orientation and image scale to the right of my image. Some of the stars
can be identified in both images which cover the same region of the sky.
Some of the bright regions at either end of the bar can be identified
in my image, especially the "hook" going up from the bottom of the bar.
A hint of the drawn out arm is visible below the "hook" region. To
see it at these wavelengths Wise was cooled to within a 8ºK of absolute
zero by a block of frozen hydrogen. The satellite was decommissioned
after the last of the hydrogen was gone.

My fall weather created havoc trying to get this image. I tried on many
nights but only three were usable for the luminance channel and two for
the color channels. Still I managed 12 luminance images and 4 each for
each color. I could have used more.

In processing I removed most of the nebulosity from the Heart and Soul
Nebulae as they detracted greatly from even seeing Maffei 2. This is
one tough object!

14" LX200R @ f/10, L=12x10' RGB=4x10', STL-11000XM, Paramount ME

Rick
--
Prefix is correct. Domain is arvig dot net