(cba:news) a new stellar menu
Joe Patterson
jop at astro.columbia.edu
Sat Oct 9 23:04:44 EDT 2010
Dear CBAers,
The recent haul of data for program stars has been really great. It'll
take me quite to assimilate it all... but I can see now that we've met
objectives for XSS0056+45, V709 Cas, and IGR0023+61. All DQ Her stars
that we want to revisit briefly *late* in the observing season
(February?), in order to nail down cycle count. We have, however,
secured the unique dividends that we get only from long time series.
Exit left, to applause.
In the evening sky, two DQ Hers that we still haven't got enough on are:
RX2133+51 and V2306 Cyg. The latter, especially, is showing a complex
multi-periodic structure I didn't expect; it may be too late in the
season to decode this, but at a dec=+32 and multi-longitude
observations, we might succeed.
And an oddity in the evening sky. HR Lyr, a classical nova remnant
which has been at ~15 for many decades. has apparently declined to 17th
magnitude. A bit out of season... but cab someone find out what the
light curve looks like in this strange - and unprecedented - state.
And in the morning sky, I again urge coverage of RX0704+26 (Gem) and
RX0636+35 (Aur). Especially the former, which may reward you with
glorious light curves if you can manage a time resolution less than ~50 s.
Now for dwarf novae. Many of you have contributed mightily to the
campaign on SDSS0804+51 (Lyn). A very important star! (Probably a
really ancient CV.) Question is: when to stop? It's still flashing
echoes, but I suspect that time series during these echoes will not have
much probative value. I could be wrong... but the humps decline to near
zero amplitude at the tops of echoes - and the limited duration of runs
is a big handicap. *Maybe* it has a week of life left in it, and maybe
less. Just use your own intuition on this one - if the light curves
still look good, then it's *certainly* worth continuing.
One of the new CSS transients looks pretty interesting:, with about 2.2
hr superhumps: CSS 000938.3-121017 (chart and light curve on CSS website
- which identifies the stars by *date* preceding the coords). Could be
rewarding.
V455 And remains good, and so does BW Scl. Still not much action on
these this... but they're the New York Yankees of CVs.
joe
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