[vsnet-alert 15723] Next HST observations: DT Oct

[Boris Gaensicke]

Dear All,

last nights HST observations of SDSS1538+5123 went well,
thank you very much for the intense monitoring!

The HST spectrum provided a bit of a surprise: at face value,
the white dwarf is very hot (~27000K) for the short orbital
period, i.e. it is nearly twice as hot as all other CVs we observed
over the past few decades.  This may hold a clue as to why the
system has no outbursts, as the hot white dwarf may prevent
the thermal instability over a fair fraction of the disc. This is a
very interesting result!

The next target is DT Oct

     May 23, 2013 23:31:07 to May 24, 2013 02:05:03

As I mentioned in one of my last messages, that one
was really worrying me, as it has short outbursts
every ~40-60days, and was due to go into the next
one any time soon. But, we were lucky, Rod Stubbings
found it in outburst last night, which means that it
should be back in quiescence by the time of the HST
observations.

Please keep monitoring DT Oct closely over the next week,
to make sure it behaves well and does fade fast enough.

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