[BAA Comets] C/2013 r1 inner coma hoods.

[Andrew Robertson]

Morning Denis,

Had a look this morning about 5am and then again 5.50am when at it's highest
in a dark sky with my 300mm Mewlon. Didn't observe the hood but did see
hints of those dark streaks in the tail. Sky wasn't too bad transparency
wise then (about mag 5 - 5.5) but the seeing was awful, about as bad as it
gets, even my 4" apo was struggling to get airy discs. I would suspect you
want good seeing to visually observe such a feature just like planetary
observing. I did observe the stellar core and I could see that the coma was
larger to one side. I did get going from 2am but not only was the seeing
just as bad but the transparency was poor due to mist/fog which slowly
cleared as the morning progressed. 

Did have a look at C/2013 V3 Nevski about 3am but transparency was awful
then (about mag 4 even though over 50 degs alt) could just about detect it
in the 300mm. As it wasn't that impressive through my 600mm under a
reasonable sky a few nights ago didn't re-visit this morning. Had a look at
a few GX's in Lmi then thought on my way to Lovejoy would just check on...

C/2012 X1 Linear. Has this brightened again? I wasn't expecting to see
anything. When I last looked at it about a month ago it was already dimming
considerably after it's outburst a couple of weeks ago, being very diffuse
and low Surface brightness. On this view it looked very similar to my memory
of NGC 2419, 'the Intergalactic Wanderer!' A similar size and similar
brightness so I made the comparison moving the scope to NGC 2419 and then
back to X1 Linear. Yes, similar brightness and size accepting they're quite
a distance apart in the sky so not side by side comparisons. The difference
being, the middle half or 2/3's of 2419 is brighter followed by a fainter
outer halo whereas X1 Linear had a stellar core which had the appearance of
illuminating the outer halo which got steadily fainter towards it's edge.
Very nice view and a reminder that it's always worth re-checking these
comets after they've diminished.

About 5.30am I thought I'd check where ISON should/would have been. I used
my 40mm Pentax giving x90 and 3.3mm exit pupil. Nothing so I engaged my
seeker program which moves the scope around the target object in ever
increasing circles. Did this twice for quite a distance and nothing but as
above, always worth checking.

A very enjoyable session under skies that a lot of people would have
considered not worth getting out of bed for.

Andrew Robertson

-----Original Message-----
From: comets-disc-bounces at britastro.org
[mailto:comets-disc-bounces at britastro.org] On Behalf Of DENIS BUCZYNSKI
Sent: 11 December 2013 19:26
To: comets-ml at yahoogroups.com; Comet-Images at yahoogroups.com; BAA Comets
discussionlist; asvcometsection at yahoogroups.com
Subject: [BAA Comets] C/2013 r1 inner coma hoods.

Hello all,
I imaged  this bright comet in the early hours of Dec 10 and upon processing
my images taken with a C14 and ST9XE ccd I noticed thas there seemed to be
features in the inner coma which look like parabolic hoods. These look like
the features seen in images of C/1995 O1 Hale-Bopp. Has anyone else imaged
these features in the inner coma of this comet. I cannot remember seeing
recent images showing these type of feature. I have seen the swept back
curved structures inside the coma but not these hoods. Any comments are
welcome. Image is located at :

http://britastro.org/baa/index.php?view=detail&id=2067&option=com_joomgaller
y&Itemid=200

Denis Buczynski
Tarbatness Highland Scotland
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