ASTRO: NGC 4331

NGC 4331 is a very weird galaxy in Draco west of the bottom of the bowl
of the Little Dipper. Redshift puts it about 74 million light-years
away. A single Tully-Fisher measurement say 87 million light-years.
The NGC project says it is an irregular galaxy while NED goes a bit
further saying Im? The I for irregular and the m for Magellanic type,
that is having characteristics of the Magellanic Cloud galaxies. The
CGPG maybe says it best: "Blue post-eruptive oval patchy compact with
comet-like plume, d = 2' north-south immersed double knot." I assume
that double knot is the odd pair of near star-like features in the lower
part of the galaxy. To me it looks like some one celled protozoa I used
to photograph as a kid through my microscope. Just a lot bluer than
they were. Often a galaxy as weird as this one is the result of some
interaction. I found nothing much within a 90 minute radius that looked
like it had tangled with another galaxy though I did find a surprising
number of galaxies at about its distance, 14 of them with NGC 4319 the
most interesting looking. It is much larger so could do some damage
with little harm to itself. I've added it to my to-do list. It lies
some 51 minutes nearly due south and is considered by one paper to be
somewhat disrupted.

This is a little studied area of the sky. I was unable to find anything
more on this galaxy. NED had no distance data on any other object in
the field so I didn't prepare an annotated image.

Seeing wasn't very good when I started on this one. Then after my first
three luminance frames seeing went to pot. I took 5 then the color data
then one more luminance frame before dawn terminated the session.
Seeing suddenly improved again for that last frame. Though seeing
wasn't very good for any I did use the best four. Color data had really
bad seeing of 5" or worse FWHM. I didn't realize conditions had gotten
so bad so never retook the data unfortunately. So this is the best for
now. It is on the reshoot list. Much of 2012 is on the reshoot list
and so far things aren't looking much better for 2013.

This was my last February, 2012 image. So it is on to March. And to
think I was 13 months behind a month ago. Shows how back the weather
for 2012 was. Fortunately March was likely the best month of the year
so I finally have some data to work on.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Rick
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