[vsnet-alert 15848] Re: Next HST observations: BD Pav

[Boris Gaensicke]

Dear All,

the HST observations of BD Pav went well... thanks for the help!
We got a very high quality spectrum, which, at a first glance,
suggests that the donor in this system may be slightly evolved,
definitely a very interesting data set to be analysed.

The next target is QZ Ser, and this one *has* an evolved
donor star: John Thorstensen found in 2004 that the companion
looks like a K4 star, which you would find in a very long period
CV, six to eight hours - but, the spectroscopic period of
QZ Ser is only 2h! The only explanation is that the donor
star we see today is the evolved core of a previously quite
a bit more massive companion that lost its outer layers to
the white dwarf. It will be exciting to get a good spectrum
of the white dwarf, as the abundances in the white
dwarf atmosphere will reflect those of the material
accreted from the evolved donor.

The HST observations of QZ Ser are scheduled for

Jun 21, 2013 02:29:47 to 09:14:45

QZ Ser had a superoutburst at the beginning of March,
please have keep a close eye on it until the time
of the HST observations.

Best wishes,

Boris

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For more information on this HST program, see

http://deneb.astro.warwick.ac.uk/phsdaj/public_html/12870/
http://deneb.astro.warwick.ac.uk/phsdaj/public_html/12870/Targets.html