YALO Telescope Observer's Report for 2000 Apr 25

Observer: David Gonzalez
Observed all night from 23:01 to 10:29 UTC.
Conditions were Non-Photometric most of the night.
No equipment or software problems were encountered.

Seeing and Weather:
   Beg: Seeing 1.8 arcsec, Cirrus, Winds Calm
   Mid: Seeing 2.0 arcsec, Cirrus, Winds Calm
   End: Seeing 1.8 arcsec, Cirrus, Winds Calm

Observing Summary:

Hello everyone,

Programme partially acomplished.
nb-235 was not observed as some clouds covered the area.

Rene, I'm sending you the following tapes with the 2 pm carry-all:
YALO 2000_0420 - 2000_0424  4 tapes

Charles, the instructions you gave me to do differential photometry fopr XTE1550 are the following:
(copied from your mail)

For the XTE1550, we only need photometry on ONE V-band image (your
choice).  What we want is the target (star 1) minus the average of
the comparison stars (2+3+4).  There is a finding chart which you
can see which are stars 1,2,3,4 at

According to the above, the result is the following:
V=3.43
Please let me know if this is ok as the data given by Juan and confirmed by you seem rather different.
Diff. Phot. for Aql X-1= 3.52

That's it,

David

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Submitted by David Gonzalez on 2000 Apr 26 [6:31:24]