From: paul harding
Subject: Re: [sdss3-25mlog 54] 2.5m obslog 20110321 (MJD 55642)
Date: Tue, 22 Mar 2011 09:13:57 -0400
On Mar 22, 2011, at 7:42 AM, elenam@apo.nmsu.edu wrote:
>
>                       APACHE POINT OBSERVATORY SDSS 2.5M
>
>                                 OBSERVING LOG
>                          Monday March 21, 2011
>
>                                  (MJD 55642)
>
> ----  Observing Team ----
>
> Viktor Malanushenko
> Olena Malanushenko
>
> ---- Observing Plan ----
>
> 21 Mar 2011  55642.0   MARVELS  10.1 hours
>
> ---- Observing Summary ----
>
> The most of the night was lost because of
> clouds, strong wind and high dust.
> We opened almost at 8am and observer two plates:
> 6 4591B  Broken of faint  fibers 49/50, 89/90
> 5 4673A  no broken fibers
>
> During  last night we think we obtained ~12-15K counts of dust
> and it might be good to check the mirror.
>
> There was one situation when gcamera has been disconnected, we
> restarted it and it return to operation again.
> Guider focus correction moved focus from working 750
> to almost zero when we had strong wind, clouds, and bad seeing.
> It happened several times.
When seeing is poor the guider exposure times need to be much longer
to average out the seeing fluctuations.
With 3" seeing a 15 or 20 sec guider exposures should be possible even
on MARVELS plates.
With poor seeing the FWHM difference between the OOF fibers and the in
focus fibers is much smaller so the
focus is more sensitive to outliers.
A focus value of 750 seems very large, was there some unusual
observing situation that causes this?
Paul