[vsnet-chat 636] Re: from the record of SN 1993J

[Taichi Kato <tkato>]

(Reply to the message by Dr. Marsden, referring to my post on SN 1993J fact)

Dear Dr. Marsden,

   First to mention, I was not mainly speaking of the positional error in
the original report and its consequence, but speaking of the effective usage
of public networks in obtaining early SNe observation.  Do not misunderstand.
Even without novanet, the same positional error in the original report should
have prevailed, at least to those you have initially requested for
confirmation.  Please remember I don't argue on your point the discoverer
should provide as accurate positional information as possible. (But have
arguments on your public request of the second-night confirmation, which is
enough to convince discoverers to hesitate in reporting on the very discovery
night, even though you yourself believe the circumstances of SN 1993J was
very special: enough too bright, galaxy too well-known.  I even know nova
discoverers, of novae as bright as 6th to 10th mag, who waited the next
night in order to confirm the object was not moving!  They did so only
because they were suggested to do such).

   Anyway, it has now become evident the report from the discoverer of
SN 1993J reached the CBAT timely.  None of observers you requested succeeded
in confirmation, and the time passed.  Assume if the original information
was posted to novanet, at the same time as to the CBAT, what may have
happened?  As you should have known, many amateur observers (even a university
student) and some professional observers managed to observe the supernova
at the very beginning of the night of novanet message's widespread.  The
information spread was virtually the same as the initial one you received,
and even without a FAX image, then what was the difference between your
observers and novanet observers?  How do you explain the fact many observers
succeeded in observing without accurate positional information?

   As you certainly realize, the best required instruments to confirm the
event depends on the uncertainty of the original information.  Perhaps visual
or wide-field CCD observations were the best choice on the SN 1993J occasion.
Large instruments are not always perfect in all circumstances.  If you did
request small telescope observers, it was a pity such skillful astronomers
as on novanet was not on your "complete" list.

   My conclusion is that there surely should have been a chance the supernova
to be confirmed, to be given more accurate astrometry than the original,
and initial observations be undertaken nearly a day earlier, only if the
information was let public.  Thus we can learn how that century-important
information can be so easily ruined by a decision within a small closed
community.  Of course, I have no intention to blame for anything that you
didn't issue circulars at earlier moment; but the fact eloquently tells
the power of the public network, in which certainly exist people who are
not so engaged in other things -- like SN 1993I, Comet 1993e, or a Kuiper
Belt object, as you mentioned, or are free from partner's absence --
those people who can concentrate with whole their enthusiasm on confirming
the very suspect.  You should realize the importance of the first night
of supernovae or novae is different from that of comets or minor planets.
There was plenty of time before Comet 1993e colided with Jupiter, but the
missed first night of SN 1993J can never be recovered.

Best regards,
Taichi Kato

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