[vsnet-chat 465] C/1997 O1 (comet Tilbrook)

[Fraser Farrell <fraserf@dove.net.au>]

G'day all,

I guess IAUC 6705 makes it official, so I'm going to go slightly off-topic here
in vsnet-chat and mention "comets found while trying to observe variable stars".

Justin Tilbrook is not on Internet, but any messages can be passed through me.
Also photos, CCD images, anything that looks impressive when framed and hung on
the wall for display :)

On Justin's behalf I thank those vsnetters who tried to confirm this comet and
those who sent congratulations.  Don't expect him to call you this month because
I think Kathy will kill him when she sees their next phone bill!! <g>

The English word for this observation is "serendipity".  Or in Australian
"strewth what a lucky b....!".  Justin does not search for comets.  He just
happened to be looking in the right direction at the right time, and was
familiar with the starfield.  I think Albert Jones (New Zealand) is the only
other variable star observer to accidentally discover a comet?


This discovery shows (again) the value of checking the starfields around your
favourite variables.  ** Don't just do the estimate! **  Next time it might be
_your_ name on a comet, nova, or new variable.


For those readers wondering why Bill Bradfield didn't find it first, I can say
that the sky over Bill (about 40km from me) has been almost solid cloud all
month.  Bill has recovered from his recent surgery and will resume comet hunting
as soon as the sky clears.

Because the weather here is still cloudy, I am including this very approximate
orbit and ephemeris.  I know some vsnetters look at comets, so I hope you will
email me some observations to help improve these numbers.  Please....

------------------------------------------------------------------
C/1997 O1  (Comet Tilbrook)
Orbital solution from 9 observations Jul 22-23 UT.

Perihelion 1997 Aug 2.2    period 3.37 years
   a    2.250     peri    0.48
   e    0.569     node  303.44
   i   11.833     q       0.97AU

Approximate magnitude 9.5-10.0v.  Diameter ~1' arc.

Although these orbital values are about as reliable as a politician's promises,
I used them to generate positions for the next few days:
  Jul  26.0UT  12h27.3m  -15d30.7'
       27.0    12 30.0   -14 21.1
       28.0    12 32.9   -13 05.5
       29.0    12 35.9   -11 43.3
       30.0    12 39.0   -10 13.6
       31.0    12 42.4   -08 35.9
Moving rapidly north into the Virgo galaxies.
------------------------------------------------------------------


Incidentally,  TV Crv was <13.3 on July 22.  Justin didn't neglect his _real_
duties as an observer :)



cheers,
Fraser Farrell

http://vsnet.dove.net.au/~fraserf/   email: fraserf@dove.net.au
traditional: PO Box 332, Christies Beach, SA  5165, Australia

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