[BAA Comets] Introduction

[Roger Dymock]

Hi Tony,

Pleased to hear from you and that you are finding the Project Alcock website useful. Please do
contact me if you run into any problems. 

A few points;
- you can't use stacked images with FoCAs
- although Jon Shanklin doesn't use MPC formatted reports you should still send them to the MPC (and
TA if you wish)
- any software that will draw a profile through the head of the comet and allow you to work out the
size of the coma can be used. I just happen to have AIP4WIN and Excel. I believe Graham Relf's GRIP
will do the trick and you could also try Iris and they are both free. I must check them out sometime
- I usually take 5 images of any particular comet with somewhere between 10 and 20 mins between
images. This usually allows for the comet to move away from any nearby star that might interfere
with astrometry or photometry

Your map ref puts you somewhere near the south coast of Spain - is that correct?

Regards

Roger Dymock
Email: roger.dymock at ntlworld.com
Tel: 023 92647986
Skype: rogerdymock67 or
Skype: rjvdymock
MPC Observatory Code: 940
Project Alcock http://www.britastro.org/projectalcock/


-----Original Message-----
From: comets-disc-bounces at britastro.org [mailto:comets-disc-bounces at britastro.org] On Behalf Of Tony
Angel
Sent: 23 July 2014 23:53
To: Comets-disc at britastro.org
Subject: [BAA Comets] Introduction

Hi,

Thank you for letting me join this group.  After reading through the past messages on here I can see
that there are a few people I know. For those who do not know me I have been a member of the BAA for
about twenty years, (though most of the time sitting at the back).  I have been spending a fair
amount of time observing comets for the past twelve months. I am still low down on the comet
learning curve.

I have mainly been doing basic imaging  - on average about five comets a night with exposure times
between 5 and 30 seconds and between 20 and 240 per comet. Mainly I first image the popular ones and
then go for dimmer mag 14 to 20 ones - though at the top end I get more negatives than positives, (
I have only managed one of C/2013 UQ4) . I have submitted a small number of images to the section.

I started to use Astrometrica with the help of Richard Miles (a lot of help!). I can get the
astrometry to less than 1 arc second.  I have been reading George Alcock project pages so I know
that I need to use two catalogues with Astrometrica to obtain the astrometry and photometry. I also
realise that I need to learn FoCAs, Kphot, AIP4WIN,  Aladin and COBS to be able to produce results
good enough for submission to the Comet Section as from what I can see the section is not interested
in MPC formatted reports - is that correct? As I mentioned I am still low on the learning curve, so
do not know how long it will take me to learn this tools, though I am slightly familiar with AIP4WIN
and Aladin.

There are a couple of things I am not clear about. The main one is to do with the number of
observations and the time gaps per comet per observing session. Chatting to Charles Bell in the USA,
he tells me that he takes a set of timed exposures and make 3 stacks, one  stack per submitted
observation, each observation being 9 or more exposures . This usually gives him 3 observations over
30 to 60 minutes per target, though if it was a new target then the time span would be longer.  Does
this fit in with the Section requirements.  He did mention that what he does was the same or similar
to what Peter Birtwhistle does (I do not know Peter, but have seen his web site).

Most of the time I use a 2x2 binned ST8 with a C14 at F11 which gives me roughly an arc sec per
pixel. I sometimes also use an ST7 on a 4" F4 Refractor for wider fields.  I am just starting to
test a 24" F4 Newtonian which I have just installed, though I expect to have some teething problems.
I have a reasonable horizon. My location is 36.876426, -3.249940 on Google maps.  I normally manage
to squeeze in about 200 nights a year.

Again thanks for letting me join.

Tony Angel
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