[vsnet-chat 917] Re: comments NGC4462 (Filippenko)

[Yamaoka Hitoshi <yamaoka@rc.kyushu-u.ac.jp>]

Dear all,

Additional comments for Taichi Kato's note:

>   On the contrary to the Filippenko's above comment, the CBAT seems to be
>more enthusiastic in introducing addotional constraints to discoverers,
>which, if strictly followed by an observer, may result in an unrecoverable
>delay of a day or even more.  The observer may be requested to take a second
>night image in order to verify the suspect supernova is not a foreground
>asteroid.  The CBAT's statement is outlined in IAUC 6737, and I made the
>following comment in vsnet-chat 584.

These CBAT's constraints are very widely distributed because it was
published in IAUC itself.  Also it was recurrently described by Dr.
Levy on Sky & Tel magazine, which has helped to a wider expance.
Consequently, these constraints tend to be kept strictly by many SNe
hunters, and thus the "golden time" tends to be lost. 

For recent example, I have heard that English TA group, the discoverer
of SN 1998aq, had construst the confirmatory procedure which follows
at least first three constraint of the CBAT. (Could you describe it
more precisely, Dr. Hurst?)  SN 1998aq was discovered on Apr 13.05 UT,
and was confirmed by the other TA group observer at 13.09 UT.  They
also confirmed at this time that it is moveless and not one of the
known asteroids.  But they kept the discovery to themselves until the
second-night observation made on 13.81 UT.  Finally, IAUC 6875 noticed
it without any further confirmation, which was distributed on 14.73
UT.  Only after the publication, we have gotten to be able to alert
that this SN is on the Virgo distance and especially noteworthy,
though some local(small-community) mailing-lists were reporting the
discovery. 

Of course, I am not intend to criticize the procedure of TA group.  I
only guess that it should be a time for make a correction of the
threshold for the report of discovery to CBAT, and it should be
re-announced on IAUC.  And, in practice, we novae and SNe researchers
should say more laudly about the importance of the early phase of SNe.

Sincerely,
Hitoshi Yamaoka, Kyushu Univ., Japan
yamaoka@rc.kyushu-u.ac.jp

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