Occultation of iota Cancri by (411) Xanthe April 18 UT by Charles Broward - New 2007 April 18, 21h UT

From: Dunham, David
Sent: Wednesday, April 18, 2007 2:32 PM
To: 'Charles Broward'; Bill Helms
Subject: RE: Iota Cancri revisited

Chuck,
     The gradual disappearance and reappearance that you recorded 
were probably due to Fresnel diffraction of the star's light at the 
edge of the asteroid, probably enhanced by the star's angular 
diameter.  Thanks for your observation and quick analysis. 
     David 

-----Original Message-----
From: Charles Broward [mailto:cbroward@ufl.edu]
Sent: Wednesday, April 18, 2007 2:27 PM
To: Bill Helms
Subject: Iota Cancri revisited

Hi,

After studying the video that Bob and I took at his location 
(29.78/82.09),  it looks like our event started at 8:56:12.11 and 
ended at 8:56:18.12. The times were derived from WWV and my vidio 
editing program which allows stepping at .01 sec intervals.  
Duration was 6 seconds. 

It was interesting that Iota Cancrii took .06 sec to dim, and the 
same to reappear.  The duration time is from first obvious dimming 
to last (undimming?) was derived from stepping thru our video. 

Was this dimming a result of scintillation of star image due to 
atmosphere? 

Telescope was C-8 on GM-8 mount.  Camera was Supercircuits 164 
(.0003lux). Video captured using a ADS DVDXPRESS DX2 video capture 
device.  WWV received using a Kenwood TS-680 transceiver. 

We also used a Meade 5 inch refractor, and a tape recorder plus WWV 
to create a audio tape. 

Slight haze, but stable seeing.  Post occultation Saturn observation 
indicated seeing was pretty decent at 250 X. 

Three minutes prior to event, my drive battery died.  Managed to 
splice a new one in place.  WWV signal quality was not good. 

This was a fun event!

clear sky
Chuck

-------------------------
Chuck  Broward
WretchedSky Observatory
Melrose, Florida
352-475-1014
cbroward@ufl.edu