Dear CBAers, There's a new class of interacting binaries in town.About ten years ago a few papers were written about a peculiar star, a CV-look-alike some of the time. I attach the one written by Thorstensen & Armstrong. The star turns out to be also a gamma-ray source and millisecond pulsar!
There are two other known stars of this type. One is in M28, not readily observable by earthbound telescopes. The two that can be observed are listed below. They're usually in the range 17-18 mag - no picnic - but very little is yet known about the magnitude variations of this new type of compact binary. Outbursts, low states, recurrence periods... we're mostly ignorant concerning all these matters - that we'd like to know, and that we might well find out.
In addition, there are two other stars that live in quite small Fermi error circles, and that have spectra resembling CVs. Are they CVs? Are they gamma-ray sources, or are they in Fermi error circles by accident? And are they millisecond pulsars? We don't know any of the answers... but we might learn plenty from studying the nightly light curves.
Since this subject is so new, we don't exactly know how to observe these stars. Fast, slow, once a night, long time series... who knows?
The CBA is in a pretty good position to explore this subject.See what you can find out! Their charts and positions are attached and below.
Re other stars, we're finished with CP Puppis and V745 Sco. AM CVn is going well... and may it continue! I'm hoping for more action on V406 Vir - and BK Lyn, too.
joe p -------- Original Message -------- Return-Path: <jules@xxxxxxxxxxxxxxxxxx> Millisecond Pulsars/LMXBs in transition PSR J1023+0038 10 23 47.6 +00 38 41.0 2000.0 Chart reference http://adsabs.harvard.edu/abs/2005AJ....130..759T XSS J12270-4859 12 27 58.75 -48 53 42.9 2000.0 Chart Reference http://adsabs.harvard.edu/abs/2006A%26A...459...21M CVs in Fermi Error Circles 1RXS J083842.1-282723 08 38 43.47 -28 27 01.5 2000.0 Swift J1544.6-1128 15 44 39.3 -11 28 04.0 2000.0 Chart reference none (see attached) Spectrum reference http://adsabs.harvard.edu/abs/2013A%26A...559A..58M
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