Vol 49, No 4, April 2012 - BAA Lunar Section
Vol 49, No 4, April 2012 - BAA Lunar Section
Vol 49, No 4, April 2012 - BAA Lunar Section
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Occultation news, <strong>April</strong> <strong>2012</strong><br />
Tim Haymes<br />
Double star occultation detected with video in the UK<br />
Alex Pratt (Leeds) reports that ZC3524, a mag. 6.9 star in Pisces which was occulted on 2011 <strong>No</strong>vember 06,<br />
was indeed a step event. Closer examination of the video by Jan Manek (IOTA total occultations regional<br />
coordinator for Europe) clearly indicated two stars separated in time by 11 video frames, a time difference of<br />
0.4 sec. The reduced light curve (see diagram) shows the fainter component disappearing first.<br />
Alex writes: ‘The recording was made with a Mintron video camera operating at 25 frames per second, at the<br />
prime focus of my 20cm aperture f/20 Maksutov-Cassegrain telescope. Embedded times accurate to 1ms were<br />
generated by a GPS video time inserter’.<br />
Right: Frame from Alex Pratt’s<br />
video of the occultation of<br />
ZC3524 on 2011 <strong>No</strong>vember 06.<br />
‘Observing conditions were not<br />
good. The gibbous Moon was<br />
86% illuminated in a hazy sky,<br />
with the disappearance occurring<br />
at a small cusp angle of 19°’.<br />
The recording is being analysed<br />
further by Brian Loader (NZ) who<br />
is expecting to obtain improved<br />
orbital data and magnitude<br />
differences for the double.<br />
Doubles listed for <strong>April</strong> are<br />
included with the general<br />
predictions for Birmingham. Observations of these are most welcome.<br />
22<br />
<strong>BAA</strong> <strong>Lunar</strong> <strong>Section</strong> Circular <strong>Vol</strong>. <strong>49</strong> <strong>No</strong>. 4 <strong>April</strong> <strong>2012</strong>
Change language