(cba:news) Hercules reappears in strength
jop at astro.columbia.edu
Sun Jun 10 07:17:56 EDT 2001
Two new targets in Hercules have popped up.
Tonny's announcement of superhumps in V478 Her is enormously important, as
the apparent long period (3.1 hrs) puts the star at the very end of the
Porb distribution for dwarf novae. It's very well placed for northern
observers, and at +23 deg I can have some hope (can't I?) that some of the
more northerly AU-NZ folks can study it. (Neil? Gordon? Stan?) The
2000 position is 17 21 05.60 +23 39 36.9; chart in Downes-Webbink-Shara
(PASP 4/97 catalogue as well as the current on-line version).
Definitely a cutie. Watch out for scattered light from that nearby bright
star. The variable is probably ~15.8-16.0 and fading, so demands pretty
good conditions. Send data to Tonny too, by the way.
I also today received from Dave East the first observation of the season
for V795 Her. This star - usually called a "novalike variable" -
showed a bodacious 2.8 hour superhump in the 1970s-80s, which
promptly disappeared for many years. (We looked, too.) Every so often we
look in to see if the humps will come back - in which case we can study
them. Since the star has V~12.5 practically all the time, it would be a
really nifty target.
Well it appears to be back. Can't tell for sure yet from one night, but
we should take a few more nights and then, if the hump's indeed there,
launch a full campaign. 2000 coords 17 12 56.09 +33 31 21.4, chart in
Downes-Shara as well as online version.
V478 Her is definitely of higher priority right now, since it is eruptive
and has a candidate period of high intrinsic interest. Go for it!
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