From jop at astro.columbia.edu  Sun Jul 16 10:24:35 2017
From: jop at astro.columbia.edu (Joe Patterson)
Date: Sun, 16 Jul 2017 10:24:35 -0400
Subject: (cba:news) summer stars... and some telescope "entertainment"
Message-ID: <479bff1b-2023-457f-8d47-02e60e3d90b0@astro.columbia.edu>


Dear CBAers,

Hard to resist this link:

http://www.deseretnews.com/article/865679322/Salt-Lake-County-man-builds-worlds-largest-amateur-telescope.html

And they put it on the entertainment page.  It's a great story, too, not 
just a huge telescope.  I'm not sure how it compares to Lord Rosse's
"Leviathan", nor whether the latter should be considered "amateur".

The spring /summer rains seem to have stopped here in the eastern USA. 
Comments on targets...

1. OV Boo and TCP1815+35.  Both fascinating and new dwarf novae.  As 
most of you know, we're de-emphasizing dwarf novae nowadays, mainly cuz 
they're not all that different from each other.  But these have 
certainly been winners.  I'm keeping close tabs on all your coverage of 
OV Boo... and feel that it's time to stop the campaign (barring another 
eruption, which seems unlikely since this year's is the first ever). 
I've left TCP1815 to Enrique, so he can advise on that.

2. My fascination in recent years has been with (somewhat) recent 
classical novae.  Our data shows very rapid orbital period increases in 
T Pyx and IM Nor, as well as some other close relatives of novae, the 
supersofts (these are, roughly speaking, "permanent novae"). So I 
strongly recommend DQ Her, V1974 Cyg, V1494 Aql, HR Del, V4743 Sgr, and 
V Sge.  It's best for you to adopt one of these stars and pursue it 
relentlessly (until further notice).  If the payoff subsides, I'll 
notify you.

3. IGR1955+00.  Enrique "insists" on this star, and with good reason. 
Kind of a unique star, nature not yet known.  That's why long runs and a 
wide range of longitudes are essential.

4. WZ Sagittae.  We've never done a really strong campaign on this star, 
despite its great - and still unclarified - importance in CV evolution. 
Let's remedy that oversight!  There's a recent paper which claims that 
its orbital period is decreasing... which would be very significant and 
might be true, but needs careful checking (by us).  Regular ol' 
unfiltered photometry is just fine, but there is a contaminating star 
about 8 arcsec away, so you have to be a little careful.  Short 
integrations really help on this star, as the eclipse is quite short (4 
minutes).

5. HP Lib.  Still very interested in this quite bright target.  Multiple 
longitudes very helpful, since we have to study the weak orbital signal 
amid the glare of the strong superhump (requiring accurate subtraction 
of the latter).  CR Boo, however, has reached the end of its observing 
season.

All for now.   Write with any questions!

joe p


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