[vsnet-chat 873] Re: Magnitudes, sequences, etc

[Taichi Kato <tkato>]

Brian Skiff wrote:

>      I agree with Kato-san's points about the difficulty of doing all-sky
> photometry, and don't expect most amateurs to be willing/able to do such
> observing.  But why is there not even one amateur or group that can do
> comparison sequences?  _Nobody_.

   At least to my knowledge, Kiyota-san is doing some of this kind job.
He took the first extension of Nova Aql 1995 sequence, and recently took
several fields of long-period variables.  I bet there must be much more
amateurs working on this than you think.  Not _nobody_.  The problem may
be these results are not usually issued.

   My feeling is that it's not amateur's responsibility of the lack of
motivation of getting sequence.  At least some of them have got the sequence,
but usually hesitate in publishing, this may result from the thinking:
"Such sequence with small telescopes will easily be superseded by 'final'
professional ones - I'd better wait ..."; more cautious amateur photoelectric
photometrists may think "I'll have to wait until someone else confirms
my result or publishs the supporting data, in order to avoid potential
public embarassment of providing wrong results".

>      In re the de facto adoption of GSC magnitudes in asteroid astrometry:
> this too, is a sad fact, and the net result is that we know almost nothing
> about the physical properties of the plethora of new asteroid discoveries.

   What about nova discoveries?  Some early nova measurements in IAUCs are
often discordant from the later observations, sometimes leading to wrong-
looking conclusions (e.g. t3 values).  I think the discoverers may be still
using SAO or more recently GSC for estimating nova magnitudes.  I haven't
seen these early estimates corrected later on more reliable standards.
This is one of the points nova researchers (esp. those modelling light
curves) complain.

Regards,
Taichi Kato

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