[vsnet-chat 595] Re: Novae, in particular

[Taichi Kato <tkato@kusastro.kyoto-u.ac.jp>]

Dear Dr. Brian Marsden,

    Thank you very much for your detailed explanation.  At least it seems
to me we have reached a certain degree of agreement that the main problem
you are confronting is the discoveries of extragalactic supernovae.

    Additional comments:

(1) The positional problem of SN 1993J was quite minute.  It may be actually
that that very observer missed the chance of getting the earliest spectrum,
but many others actually managed to take the spectrum even before any accurate
positional measurement was issued.  Our Okayama Astrophysical Observatory
colleagues were not an exception.  The position was revised by the first-aid
volunteer astronomers.  It sounds to me only an excuse to give that very
specific case (unsuccessful attempts are quite often attributed to inadequate
information -- of course, I am not intending to referring to that
observation).  I certainly believe a great majority of supernova researchers
welcomed the initial SN 1993J discovery alert, though it was at that time
too rough to meet your suggested standard, being distributed timely through
internet.

(2) I wonder the community of professional astronomical spectroscopists
you are referring to is a bit too biased.  Certainly many nova researchers
do not have their own telescopes available for immediate spectroscopy, but
in total, they will not be that few as you suspected.  I know many (even
in my country) astronomers who may choose suspected novae, weather and
instrument permitting, as their targets of opportunity.  Cataclysmic
variables people are not such a minority: think of more than a hundred
people usually attending conferences held anywhere in the world.
I do think observers are more requested than ever to provide as reliable
information as he or she can manage.  I agree with you in this point, but
this is not the reason that less satisfactory discovery announcements
may well be left less attended or in oblivion.

    You mention in the case of Nova Sgr 1996 that point 1 and 3 were not
demonstrated by the discoverer, not to mention point 4.  But was that only
the responsibility of the discoverer?  I have heard directly from the
discoverer that he REPORTED, but was NOT requested to demonstrate point
1 and 3.  Only what he was requested to do was to wait, wait, and wait for
the professional confirmation!  He confessed he even wished to ask
confirmatory observations to local professional and amateur observers he
may have contacts, but was advised not to do so before the CBAT gives him
credit (or some similar word I can not precisely cite here).  I want to
convince myself, as you mentioned, this was a very unfortunate, tremendously
special case, since Nova Sco 1997 was announced even before point 1 (not
to mention point 4) was achived, and Nova Cru 1996 before point 4 (it was
a quite fortunate treatment since these novae were very fast ones -- thanks
to these early alerts, the ISO could obtain IR spectra of Nova Cru 1996).

    Returning to the UBV measurement of Nova Sgr 1996 at the Mt. John,
your literal judgement on the observer's most conservative statement --
the statement "colors look more like those of a reddened nova than a normal
star" was not astoundingly positive --  sounds to me something like --
the statement "the image look more like those of a distant comet than a
normal minor planet" was not astoundingly positive (even in the presense
of the accompanying image of the object).  Is this kind of reasoning
acceptable in the field of solar system astronomy for the substantial,
would-be-fatal, delay of attempting in getting more information or further
observation (e.g. point 1 etc.), either from the discoverer or the measurer?
UBV photometry was present, showing a strong evidence of an unsual 'erupting'
object.  The blue color indicated that the object was not a chance brightening
of a usual pulsating variable.  The point 1 and 3 were not demonstrated
by the discoverer.  The point 2 was not met, and was met, as your word, only
after "a deplorable three weeks later".  So it may have been also judged,
at the time of UBV measurement, that the object may be a foreground solar
system object, having a quite unsual color.  Wouldn't it be worth notifying
the astronomical community at that moment?  But you didn't.  Wasn't it be
the fact you have been convinced that the object is extrasolar?  Then your
insistence on point 2 (and some others) would not make any sense.

Regards,
Taichi Kato

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