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IAUC 6737: Notice

                                                  Circular No. 6737
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/cfa/ps/cbat.html
Phone 617-495-7244/7440/7444 (for emergency use only)



NOTICE TO CONTRIBUTORS
     The following points can be made concerning the account on IAUC 6736.
Firstly, some sources of information about minor planets are apparently
unreliable.  Secondly, apparent absence of motion over the course of
less than several hours of an object near the ecliptic is not
a guarantee that a minor planet has not been observed, particularly
if it is near a stationary point.  Thirdly, spectroscopic confirmation
by professional astronomers using large telescopes is an expensive
proposition and should be considered only as a final resort.
Fourthly, the use of the WWW for confirmation purposes is potentially
dangerous, in that if the Central Bureau is not cognizant of who
knows of a purported discovery, a genuine discoverer could
conceivably be deprived of credit.

     In the specific case of a CCD or photographic detection of an apparent
supernova and nova, observers are henceforth requested, before
making a report, to perform at least three of the following four tasks,
if credit is expected for a discovery.  Firstly, they should make a
precise astrometric measurement of the object's position, specifying
date and time (and magnitude); secondly, they should also
observe on a second night to verify that the object is in precisely
the same location; thirdly, they should show that the object was
not present on comparable images on some other occasion;
fourthly, they should clearly demonstrate the object's nature from its
spectrum.  The first two points, in this case showing motion,
are routinely expected of CCD and photographic discoverers of minor
planets and comets.  We recognize that the fourth point is difficult
for all but experienced professional astronomers, but amateurs can
still perform the first three.  We also recognize that the first two
points, and maybe even the third, represent a problem for visual
discoverers, although a visual supernova hunter, in particular, can
in this instance clearly profit by collaborating with a colleague
who utilizes a CCD.  If bad weather is expected, it may also be
reasonable for a CCD observer to collaborate with a colleague elsewhere
for the second-night follow-up, but this should be a trusted colleague
who is contacted personally, not someone who responds to a mass e-mailing
or WWW placing.  The proliferation of internet communication greatly
reduces the security involving requests for confirmation,
particularly when the CCD images themselves are posted.  This point was
discussed at length at the meeting of IAU Commission 6 in Kyoto last
month, in that such extensive use of the internet could completely
jeopardize what is meant by a discovery and the proper assignment of credit.
The matter is of particular import in the case of comets, because the
IAU clearly wishes to continue the tradition of naming these objects
for their discoverers.

                      (C) Copyright 1997 CBAT
1997 September 6               (6737)              Brian G. Marsden