ASTRO: NGC 7497

NGC 7497
Pegasus
Penryn, California
August 2007
FS-128 (ag, ST-4)
ST-2000XM LRGB 5 minute subs

A mag. 13.9 type Sbc galaxy partially obscured by intervening dust/gas
within our galaxy. Distance is 60 million light years.

I first imaged this galaxy in 2006 and on stretching the data was
convinced I had dew on the primary mirror. I again imaged on a dry
August night of this year and found the same streaks in the image.

Checking http://irsa.ipac.caltech.edu/applications/DUST/ I was able to
confirm that it wasn't a problem with my optics but was in indeed
galactic dust.

wrote:
NGC 7497
Pegasus
Penryn, California
August 2007
FS-128 (ag, ST-4)
ST-2000XM LRGB 5 minute subs

A mag. 13.9 type Sbc galaxy partially obscured by intervening dust/gas
within our galaxy. Distance is 60 million light years.

I first imaged this galaxy in 2006 and on stretching the data was
convinced I had dew on the primary mirror. I again imaged on a dry
August night of this year and found the same streaks in the image.

Checking http://irsa.ipac.caltech.edu/applications/DUST/ I was able to
confirm that it wasn't a problem with my optics but was in indeed
galactic dust.

How many subs did you use?

I looked at the red POSS 2 plate when I put this guy on my todo list but
never looked at the blue. The dust barely shows there and I took it for
fogging on their plate. Thanks to over a month of constant clouds I'm
now zero for 15 for the objects I'd hoped to image this dark of the
moon. That was one of them, though low on the list.

I went back and looked at the blue POSS 2 plate and the dust shows quite
well there. I see I'd have likely taken too few frames of this guy
then, since I just baked the desiccant, would likely have blamed the
"fog" for not getting the chamber sealed so the desiccant was already
saturated from all the fog of late. I get a frost pattern something
like that when it's used up.

That is a far more interesting area than I expected! It just went a lot
higher on the priority list.

Rick

--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

wrote
....
NGC 7497
A mag. 13.9 type Sbc galaxy partially obscured by intervening dust/gas
within our galaxy.......

Great image!!

I remember about a year or so ago they were making a big deal on the SBIG
Yahoo Group about dust in images taken in Ursa Major. Looks like you got the
same thing in Pegasus!

George N