stars for september

From: Joe Patterson <*jop_at_astro.columbia.edu*> Date: Mon, 6 Sep 2004 14:34:30 -0400 (EDT) · jop_at_astro.columbia.edu

Dear CBAers,

Sorry for the long silence!  I've been on vacation at the Rhode Island
shore, and have been dead to email for about 2 weeks.  I'm now getting
ready to move to Massachusetts, where I'll spend the year on sabbatical.
I'll send you new coordinates when I have 'em... but email here at
Columbia will work fine.

I'm just now digging into the last two weeks of data.  But I know enough
to make some recommendations re targets for the next month or so.

Delete V1315 Aql.  The season is getting short, and we have enough.

Raise V1101 Aql in priority. Season's kinda short for this star also, but
based on its late-season performance last year, I feel sure that it will
be a rewarding target (basically with negative superhumps and apparent
dwarf-nova outbursts - just the second star known with that combination).

AO Psc and FO Aqr remain pretty good targets, for all hemispheres and all
observation lengths - because the pulse periods are short, even 1-hour
observations have value (although longer is better).

There are two new northern stars that are perfectly placed and likely to
be superb targets for observation in the next coupla months (starting
now).  Last year's coverage of LD 317 ("And" in the CV Catalogue) strongly
suggested that this is a shiny new DQ Herculis star, with a spin period of
36 minutes.  Another season of observation should nail it down, plus
provide a long-term ephemeris (for this period and the more obvious
orbital period).  Well placed, decently bright - fire away!

The other is HS 2331+3905, also "And" in the Downes et al. catalogue.
This one is considerably fainter, I think around 16.5 most of the time.
But it's another star with a fascinating panoply of short periods,
apparently representing the orbit and the pulsations of the white dwarf.
As you can see from the names, both of these stars are very recent
arrivals to the astrophysical scene, with still no "proper publications".

Because of its brightness, I'd tend to recommend LD 317 - but both are
good targets.

Since the Milky Way now rides high in the northern sky, most of the
snazzy targets now are northern.  Two that aren't are the following...

EF Tuc.  We got in a good season last year, and we'd like to get one more
before going to press.  Bright, far southern, eclipsing, superhumping, no
previous substantial publications... a great target all around!

BW Scl. Very faint, around 17th magnitude.  Widely thought to be a dwarf
nova, though no dwarf-nova eruption has ever been seen.  The real payoff
is to see one!  But my guess is that they happen very, very raraely - the
light curve is reminiscent of WZ Sge.  Meanwhile, we can at least track
the orbital period very precisely - or those of you can who can work at
16-17 magnitude comfortably.

Finally, there's V1101 Aql. I hope that some of you Australites can work
on that one as well.  With a dec of +15, it should be feasible for some of
you... and we are a little more longitude-challenged these days, now that
Major Tom has left Uzbekistan...

OK, back to the treasures of the last 2-3 weeks of data.  Happy observing!

            joe