[vsnet-chat 390] Re:

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

G'day all,

Berto Monard said:
   >Although I don't VSNETreport on them, I do monitor some of
   >those RVBs and let me tell you some are a pleasure to 'do', others
   >are a bother. Why?
   >It depends on a number of factors: sequences (lettercodes, bad or
   >inconsistent sequences, good sequences..), behaviour of the star
   >itself, and the starfield.

These comments apply to all variable stars.  

Personally I don't like letter sequences because I like to look at the
lightcurves -  without having to wait years for someone to get V
magnitudes of the field.  (This is a hint to all you CCD users! :)

A star that actually _changes_ reasonably often is of course more
interesting to watch; so is more likely to be observed.  Related to this
is the observer's ability to see changes in the star.  For example, AR
Pav (ZAND+EA 7.5-13) is boring in a tiny (or light polluted) telescope -
because it would be invisible for years.  A bigger telescope can follow
its usual restless behaviour at mag 10-11, and its long eclipses.

The starfield has a lot to do with observing pleasure.  I use two
observing lists.  The first contains all the variables I consider
"easily found" (distinctive star pattern, nearby bright star or nebula)
and this list gets observed regularly.  The variable itself is not
necessarily a bright object; for example I regularly do BI & BP Cru.

AI Sco - near a bright cluster and next to a distinctive triple star -
is definitely on the first list.  IW Car also gets on this list (even
though it doesn't do much) because it is close to R Car.  R Sct is
another winner (unmistakeable starfield and a nice little cluster).


My second list contains all the other stars; the ones I _know_ are going
to take me at least 10 minutes to find.  This list only comes out on
good moonless nights when I have lots of available observing time; even
though some of the stars on it can get quite bright (eg: S Oct).


I would also add that the readability of the chart is very important. I
find the AAVSO Atlas hard to use, because to me nearly all the dots look
the same size in red light.  Charts based on old blue-sensitive
photographs often have misleading dot sizes and I don't like them.  And
with some charts I just cannot match them to what I am seeing  (eg: the
T Cha chart).

So there is also a third list - the ones that will never get observed
until a better chart is produced!




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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