From jop at astro.columbia.edu  Sat Jul  1 15:09:40 2000
From: jop at astro.columbia.edu (Joe Patterson)
Date: Sat, 1 Jul 2000 15:09:40 -0400 (EDT)
Subject: (cba:news) Nova Aquilae 1999 No. 2 = V1494 Aql
Message-ID: <Pine.SOL.4.05.10007011444180.28065-100000@odyssey.phys.columbia.edu>


Dear CBAers,

I spent a little while studying the reports on this star (Rudolf and
Alon), and several nights' data from Lew Cook.  Everything they said
looks right to me: periodic humps every 90 min or so, amplitude 0.05 mag
or so.  Quite an amazing spectacle in a nova still 8 magnitudes
above minimum light.

There's really just one precedent for such behavior: V1500 Cyg in 1975
(and ever since).  It showed a 3.3 hr variation that turned out to
be close to Porb but not quite.  The period is continuing to slowly 
evolve towards Porb, and is today most commonly interpreted as the
rotation period of the white dwarf.  This could be a second example 
- or, it could in some manner be reflecting Porb exactly.  A third
possibility, mentioned by Alon, is a superhump.  We gotta find out!

V1500 Cyg showed pronounced spectroscopic variations at the same or 
very similar period.  Cindy Taylor and John Thorstensen are on
spectroscopic observing runs right now, so we should all agree that
their names will live in (CBA) infamy if they don't track this star
spectroscopically.  And this star is really ideal for us to track with
our usual time-series photometry: magnitude 10.5
(keep exposures short, careful about saturation) and without
hemispheric bias (RA 19 23 5.38, DEC +04 57 20.1, J2000).

So let's jump to it!  I can practically hear the slewing motors of the MDM
telescopes right now, if Cindy and John know what's good for 'em.

   joe

By the way this was that quite spectacular naked-eye nova near Altair last
fall - the Universe Semester's only nova!


From jop at astro.columbia.edu  Sun Jul  2 13:25:54 2000
From: jop at astro.columbia.edu (Joe Patterson)
Date: Sun, 2 Jul 2000 13:25:54 -0400 (EDT)
Subject: (cba:news) Stars of the week
Message-ID: <Pine.SOL.4.05.10007021308001.28553-100000@odyssey.phys.columbia.edu>


Dear CBAers,

You've already received this from Tonny, but I thought I would emphasize
it.  I was pessimistic that we could do anything in Virgo this late in the
season, but obviously I was wrong!  It's important that we follow these
eclipses as the star declines from (super)outburst.  We really need all
longitudes cranking away on this one.  It'll take very little observing
time since the star quickly sets - but try to get in a quick session
before your main target.

Dave Skillman got a long run on V1494 Aql last night, which suggested
there might be another period present of 19 minutes.  We won't be sure of
these matters until we have a few more good nights of coverage, including
NZ or Europe which we need to crack the daily cycle count.

Two great equatorial stars... fine days in the CBA.


     joe


---------- Forwarded message ----------
Date: Sun, 2 Jul 2000 14:54:50 -0000
From: Tonny Vanmunster <Tonny.Vanmunster at advalvas.be>
To: cba-news <cba-news at cbastro.org>,
     vsnet-alert <vsnet-alert at kusastro.kyoto-u.ac.jp>
Subject: (cba:news) [vsnet-alert 5052] Detection of eclipses in the dwarf nova 1432-0033 
    = Vir4

Dear colleagues,

An analysis of the 1432-0033 = Vir4 CCD data sets of CBA Belgium and CBA Pakuranga, securely has revealed the existence of eclipses in this newly detected [see VSNET-ALERT 5037] UGSU type dwarf nova. Data were obtained on June 26/27 (CBA Belgium), June 28/29 (CBA Belgium), June 29 (CBA Pakuranga) and June 30, 2000 (CBA Pakuranga).

Eclipse profiles have an average depth of 0.9 mag and a duration of approx. 15 min (visual inspection of light curve!). The orbital period of 1432-0033, derived from eclipse timings spread over the period mentioned above, is 0.0726 d. More precise values will be communicated after a detailed analysis of all available data has been carried out.

Best regards,
Tonny Vanmunster (CBA Belgium)
Fred Velthuis & Jennie McCormick (CBA Pakuranga)



From jop at astro.columbia.edu  Tue Jul  4 22:54:08 2000
From: jop at astro.columbia.edu (Joe Patterson)
Date: Tue, 4 Jul 2000 22:54:08 -0400 (EDT)
Subject: (cba:news) stars for the road
Message-ID: <Pine.SOL.4.05.10007042239100.4194-100000@odyssey.phys.columbia.edu>


Dear CBAers,

Tomorrow morning I leave Bio2 for New York City again, so I'll be
incommunicado for maybe a week.  Here's the latest status...

1. V803 Cen: time to end the season's work.  A pretty good season!
Paper reporting the earlier work in May 2000 PASP - pretty consistent with
this year's behavior.

2. V603 Aql: somewhat disappointing.  Cap'n Bob has been hitting it hard,
but so far not the help from other longitudes that I had hoped for.  The
main characteristic, though, is fairly clear: only a positive superhump
this year.  This makes it a less shiny toy - we can't watch the interplay
of the two superhumps.  Unless some of the New Zealanders have been
hitting it hard, I'd say this one should retire in favor of the other
nova in Aquila.

3. V1494 Aql: Wow.  A very, very complex power spectrum in this guy!  We
absolutely need multi-longitude coverage, and as much as possible.  This
is going to be a very rewarding target - some really novel astrophysics
likely to be at work for such a bright object - and is absolutely
accessible to the humblest of scopes.  This will surely be one of our best
campaigns of the year, go as soon as you can and as long as you can.
By the way I see a fairly big peak around 7.4 c/d, so I imagine this is 
the fundamental frequency; but the power spectrum is complex, so we need
your data to figure it out.

4. Our program to measure timings in DQ Her stars continues apace.  FO
Aqr, AO Psc, V1223 Sgr, V709 Cas are the stars in season.

5. HP Lib season is over too.  Very fine season, thanks to the Kiwis
mostly.


     joe



From jop at astro.columbia.edu  Sat Jul 15 13:13:14 2000
From: jop at astro.columbia.edu (Joe Patterson)
Date: Sat, 15 Jul 2000 13:13:14 -0400 (EDT)
Subject: (cba:news) Midsummer and midwinter stars
Message-ID: <Pine.SOL.4.05.10007151249570.7790-100000@odyssey.phys.columbia.edu>


Dear CBAers,

Back in NYC a few days now, what a great feeling to be home!

The campaign on V1494 Aql is going quite well, with very frequent hits by
Dave East and Cap'n Bob.  A strong signal at 14.851(12) c/day is certainly
present.  There's some structure near 0.5 and 1.5 times this frequency,
but with the present longitude distribution I'm afraid it's pretty close
to the noise.  A few runs from Fred and Jennie, and Neil Butterworth, have
helped but the signals are just too weak to be sure.  This is a 1999 
nova and is continuing to slowly fade, so the periodic content is
likely to evolve over the next few years.  The examples of Nova Cyg 75
and Nova Cyg 92 showed that on a timescale of a few months, the periodic
structure can change significantly.  So let's take it off the critical
list right now, observe it more leisurely through July and August, and
perhaps do a mini-campaign in Sep-Oct.  It remains a good target
throughout, though, especially if you want something bright.

The Hamburger star, 1450+63 or thereabouts, was written up and submitted
by Tonny to IBVS a few days ago.  Good job.

An interesting dwarf nova, DM Lyrae, just went into superoutburst.  This
is a very good one to do, definitely worth banging the CBA alert drums
for.  We have a Porb, so knowledge of P(superhump) will give us the
precious epsilon! [=(Psh-Porb)/Porb]

And V751 Cyg is back in the sky bigtime - let's jump on that one with full
CBA fury, and couple with last year's campaign to give us a one-year
baseline for period solution.  Pronto.  Bob, this would be a good one to
do multicolor, but 3 or even 2 passbands would be fine.

Then there are the DQ Hers: always lovely, always underappreciated!
DQ Her, FO Aqr, AO Psc, V1223 Sgr, V709 Cas.


     Joe



From jk at cbastro.org  Fri Jul 28 19:31:10 2000
From: jk at cbastro.org (Jonathan Kemp)
Date: Fri, 28 Jul 2000 13:31:10 -1000 (HST)
Subject: (cba:news) [vsnet-alert 5142] 1H 1933+510 outburst (Bryja) (fwd)
Message-ID: <Pine.GSO.4.10.10007281330420.25365-100000@ohia.jach.hawaii.edu>

---------- Forwarded message ----------
From: Joe Patterson <jop at astro.columbia.edu>
Subject: (cba:news) [vsnet-alert 5142] 1H 1933+510 outburst (Bryja) (fwd)


Dear CBAers,

Snip, snip...

This looks interesting!  A strong X-ray emitting, DQ Her star candidate.
If you've got the chart, go for it!  V1494 Aql and several DQ Hers remain
the best objects del sur.

    joe


1H 1933+510 outburst (Bryja)

Date: Sun, 23 Jul 2000 04:03:37 -0500
From: cob585f <cob585f at mail.smsu.edu>

To anyone interested:

I have found the "nova-like" CV 1H 1933+510 = Cyg2 in the Downes & Shara
catalogue (1987, PASP 105:127) to be more than three magnitudes high.
Clouds are coming in at my location, but I have been observing it since
5.85 UT (July 23, 2000). It's now 8.5 UT, and I have taken several CCD
images.

Downes & Shara list this star as "nova-like" which implies it's not a
dwarf nova. If this is correct the star is most likely a VY Scl star
that's been spending a lot of time in the low state. However, I think
it's likely a dwarf nova of some kind because of its photometric
behavior. I need to confess that because of a mis-ID on a finding chart
I failed to notice an earlier outburst that (luckily) I caught on the CCD
frame anyway in November 1999. The mistaken identification on the earlier
images was something I just discovered a month ago, but they all have
the correct star visible in the field. I have observed this star in
June 1999, November 1999 (outburst), and then on multiple occasions
from late May 2000 to the present. Except for the November 1999
outburst, the star has stayed fainter than 17th magnitude. Because
of the earlier outburst, I've been trying to observe it every chance
I get to see if the outburst repeats. Well, tonight it did! It's
again up at least three magnitudes, and there is no mistake about
which star it is this time.

I lack the equipment necessary to get good time resolution which would
help settle the question of what type of CV this star is. I'm posting
this in the hope that someone else can pick up the observations where
I'm about to leave them off. The orbital period of this star in listed
in a table in Warner's book at approximately 3.3 hours. Even if I could
get good time resolution, the clouds here are doing me in. I haven't
been able to observe continuously because of them and high humidity.

So I hope I can pass the baton to someone else who can follow up on
this.
-- Claia Bryja
Southwest Missouri

cob585f at mail.smsu.edu