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(cba:news) CBA stars for August (Joe Patterson) [2017-08-09T01:19:47Z]


Dear CBAers,

We're finally finished with DQ Her for the year. Great, great coverage by Jim Jones and Lew Cook.

Let's put V1974 Cyg and WZ Sge at the head of the class for (northern) August runs. For the latter, note there is a potential contaminant about 8 arcsec away. I presume that it's feasible for you to cleanly exclude this star; but if it's a threat, then better to use a big aperture and cleanly include it.

V1494 Aql is also a very desirable target for August - near the equator, so a target for everyone.

Other good targets: V4743 Sgr, HP Lib, and especially V Sge (latter two ideal for smallish scopes or mediocre conditions; no one has bit yet on V Sge).

But as usual, we especially value LONG runs - not much beyond 2 airmasses, but long is highly desirable!

joe

previous message:


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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