(cba:news) CR Boo and UMa transient
jop at astro.columbia.edu
Fri Mar 31 10:27:25 EST 2000
We're enjoying a fine early spring in the Northeast - just about
average for clear nights, but great for golf and baseball. Much
treasured by those of us living in concrete jungles!
We got pretty good response on DW UMa - from Dave East, Cap'n Bob,
and Brian Martin. But the star disappointed - no big superhumps like it
showed in 1996 and 1997. Time for us borealites to move on. Then a
couple of days Ron Remillard announced a new X-ray transient in UMa
(where there sure are a lotta fireworks this year), and optical ID from
Uemura and Buczynski has pinpointed the position: 11h 18m 10.79s, +48d
02m 11.2s (2000.0). It appears to be about 13th magnitude. Let's get
cracking on this guy, it's definitely the object of choice for northern
Until the UMa transient, I wanted to kick off the 2000 all-site
campaign on CR Bootis, which at 1346+08 is well-placed for everyone now.
John Thorstensen will obtain spectroscopy in a week's time, so I wanted
to start the photometric campaign now, and go for about six weeks. We
did a fair job on CR Boo in 1996, but that was before we established
a strong node in NZ. Now we can do much better in terms of global
coverage, which is essential here because the putative dwarf-nova cycle
is about 18 hours. Then the UMa transient came along. Here's a
compromise: could the southern observers start the campaign now, and we
in the north will do CR Boo as a secondary target? That way we'll get
some global coverage now, to be simultaneous with spectroscopy, and will
switch to all-site coverage when the bloom is off the UMa rose.
I have to admit, it might be a little dangerous to switch off V803
Cen so soon. But as Stan (and Andrew Pearce) recently remarked, it seems
to be doing its up-and-down cycling thing - and we've already documented
that pretty well. We know a lot less about CR Boo, and we could know a
lot more, since it's accessible to all of us.
Fred Velthius and Jennie McCormick sent some nice data on VZ Pyx,
which I haven't yet been able to study thoroughly. I did study the amazing
Kiwi data on OY Car, which form one of the finest records of a dwarf-nova
outburst I have ever seen! I'll send some of that as soon as I get out of
class this afternoon.
UMa transient and CR Boo - pretty simple this time!
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