Hi, all:
I
disappeared for a liitle while because I needed to sleep!!
That's
true, Stan, there are slightly variable stars for comparison but that "slightly"
is slightly enough for the observations to be good.
When the
star is out of the eclipse (at 1.94/ 1.96) I always use gamma Velorum and iota
Carinae, taking a look at beta Carinae in case gam Vel has done something
strange. There has never been a problem with that.
When
delta Velorum is in eclipse (2.2 / 2.3) the comparisons are gamma Centauri, iota
Carinae, zeta Puppis and kappa Velorum.
So
there is not a big problem because gamma Vel ( the worst comparison) is not used
during eclipses and can be changed for beta Car if something is wrong.
The
complete list is:
beta Car = 1.67
gamma Vel = 1.70 (v 1.68-1.75)
gamma Cen = 2.16
iota Car = 2.24 (v?
2.23-2.28)
zeta Pup = 2.25 (v 2.22-2.29)
kappa Vel= 2.49
The ranges are extreme values, so the "variable" comparison stars are
usually less variable than that.
We have observers in South Africa, Australia and New Zeland and South
America, so a complete coverage is possible and an intensive observing campaign
should start before the November 1st event.
Regards,
Sebastian.
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