[vsnet-chat 599] IAUCs 6736 and 6737

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

G'day all,

I presume most of you have seen the contents of IAUCs 6736 and 6737,
concerning the reporting of possible novae/supernovae, etc.  I would guess
a lot of us also subscribe to the Supernova Network and have seen the
messages which started this fuss.

Speaking as someone who receives dozens of such reports every year - often
from less experienced observers or members of the public - I regard it as
part of my job as the local variable star expert to check out such reports.
Even though 19 out of 20 turn out to be planets, asteroids, known
variables, or the "discoverer" couldn't read a chart properly.  I am sure
that many of you get similar reports.

It is my job - and every vsnetter's job in my opinion - to provide this
service because I _have_ the ephemerides, the charts, the contacts, a
good (small) telescope; and the observing experience to confirm (or deny)
these discoveries.

The majority of observers do not have access to the latest catalogues,
news, software, online services, and other goodies most of us old hands
take for granted nowadays.  The new chums may not be aware of the need for
a precise and accurate position, a magnitude, and some basic checks for
known objects and any movement of the target.  I reckon I have saved dozens
of inexperienced observers from acute and public embarrassment; without
me even having to go outside.

If the discovery survives this "filtering" process, I also know the
appropriate people to contact with the news.   VSNET for example....


The IAUCs do raise one valid point about the Internet making it more
difficult to identify the true discoverer(s).  For those people concerned
about such things; I would suggest a copy of your email be sent to CBAT at
cbat@cfa.harvard.edu ; as well as vsnet-alert, the Supernova Network, your
friends, or whoever else you might tell.

For those people worried about Murphy's Law and email servers, a facsimile
(which is automatically time-stamped) to CBAT at: + 1 617 495 7231 may
ensure your place in astronomical history.  Provided someone else didn't
find it 12 hours before you did!


Commenting on the specific case referred to in the IAUCs:

It is disappointing that these "supernovae" turned out to be asteroids near
their stationary points.  I myself fell into this trap with 5 Astraea once,
and I have also been caught by stars omitted from variable star charts on
at least two occasions.

The wide availability of computer ephemerides/atlas programs has reduced
these false alarms but not eliminated them.  There is the problem of typo
errors and omissions in the source catalogues (stellar and nonstellar) used
by these programs; and sometimes the default values used by the program can
cause embarrassment.

Unfortunately with asteroids some commercial programs work from only one
set of orbital elements.  AFAIK only GUIDE and The_Sky use sets of
rigorously pre-computed osculating elements for their asteroids.  Does
anyone know what software was used to check this instance?

Not all users are aware of these limitations; and tend to assume that "the
computer is always right".  I recall one recent argument with a science
teacher (of all people) who was adamant that _no_ deep sky objects existed
south of Dec -30 because SkyMap didn't show any.  It wasn't until I showed
him how to change SkyMap's "deep sky display" from Messiers to All Objects
that he believed me!


Personally I would much rather spend an hour confirming - or denying - a
possible nova, bright supernova, X-ray transient, etc; rather than risk
missing the important stages of a real event.  I have the exclusive use of
my telescope, I don't need to justify my observing time - and those most
important photons only go past us once....


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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