From: Mamoru Doi (mdoi@subaru.naoj.org)
Date: Tue Apr 09 2002 - 08:49:45 PDT
Hello,
We finished the first night of Suprime-Cam search in Apr.
summary of exposures Apr.8
condition: hazy
A663 i' 4minx8 0.75arcsec
Rc 5minx5 0.75arcsec
SDFn Rc 8minx5 0.75arcsec
SDFe i' 6minx9 0.65arcsec
SS1 i' 6minx8 0.6arcsec
SS3 i' 6minx8 0.6arcsec
SS2 i' 6minx8 0.6arcsec
SS4 i' 6minx8 0.55arcsec
1520 i' 5minx5 0.50arcsec
stnd.i' 2 spectrophotometric stds. El=75d,40d
(image size variation +-0.05arcsec typical)
We successfully took SS1-SS4 in i'.
The sky was hazy through the night, though we took SS1
and SS3 at reasonably good conditions. The seeing was
reasonably good, sometimes better than 0.6arcsec (close
to 0.5arcsec).
If we compare images taken tonight with images taken in March,
new images are deeper. Since SS3 is also best in March,
I suggest searching from SS3.
Naoki and Yuji gets up and are starting the analysis.
The problem was that the sky was hazy and transparency changed
significantly. So we could not calibrate the zero point of SS1-4.
We will try calibrations on Apr.10. We took spectro-photometric
standard stars, but probably these are probably not useful.
We also took 1520 in which we found 2001cw last year.
Since HST follow-up of this SN was carried out, we want to take the
final reference for Suprime-Cam to get photometry of early phase.
We tried to start exposures, but hardware error (Auto Guider)
occurred. We did open tracking with 5min exposures. The image
size was good though, 0.50arcsec or better. We have to
add more exposures to finish this reference.
Eventually we have to discuss the plan for Apr.10.
The biggest decision would be that whether we put more time to z'
of SS1-4 or to put more time for SDF (for May).
target band exp. time (with readout)
SS1-4 i' 6minx4 0.6hours (calibration)
SS1-4 z' 5minx9x4 4.3hours
1520 i' 5minx15? 1.9hours
SDFn Rc 8minx10 1.7hours
SDFw i' 6minx10 1.3hours
SDF U 20minx5? 1.9hours
If we consider loss time for telescope pointing etc., maximum
time we could use is about 8.5hours.
One possibility is that we omit SDFw which reduces SDFn
and SDFU.
SDFn Rc 8minx10 1.7hours
would be enough to trade telescope time in May.
We could do search in SDF and SDFe.
The other possibility is to reduce z'-band exposures in SS.
We just take z'-image in SS3. Then if we skip SDF_U, we
will be able to negotiate telescope time trade for SDFw.
I will go down to HP soon.
Tomorrow I will get up early afternoon. I have to join the
observations for the big project tomorrow night, since we
need contributions to the big project from which we want
to carry out search in SDF.
Cheers,
-Mamoru
Mamoru Doi
Institute of Astronomy
School of Science
Univ. of Tokyo
voice +81-422-34-5084
fax. +81-422-34-5041
doi@ioa.s.u-tokyo.ac.jp
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