[vsnet-chat 4346] re V0374 And

[crawl@zoom.co.uk]

Hiya Ondrej

This one is Worley 1, a binary with a 14th mag companion somewhere between
4.4" and 8.2" distant, depending on which catalogue you look at, which
suggests a chance alignment in this case, given the primary's proper motion.

Again it's a nearby red dwarf.

Unfortunately there is no Tycho epoch photometry for V0374 And, despite the
fact that there is supposed to be epoch photometry for all Hipparcos
variables (though their is a limiting magnitude cutoff too re inclusion in
the annexes, I can't see why V1436 Aql can get in and not V0374 And.  It
may mean there aren't sufficient datapoints, as I think that is another
criterion).  Invariably a lack of epoch photomery means the data isn't very
good.  A point to be borne in mind.

Just in case I said it too strong:  faint Hipparcos objects don't have to
have iffy data, but they _can_ have.

With respect to the degradation of the Hipparcos instrumentation over time:
cosmic rays made the scanner less receptive after a while, like having a
dirty objective.  This was allowed for in the solutions by appropriate
corrections.  The problem was one that increased over time, so it shouldn't
really have caused any timing regime to have been built into the
observations, save possibly at the level of the full duration of observations.

Cheers

John

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