OBSERVER'S REPORT for WHT/Autofib2 WYFFOS run, 20-23 Oct 2001

Observer: Mat Page (MSSL)
                

Instrument: WHT+AF2+WYFFOS


Grism     : 600B


wavelength setups: 5500A central wavelength for extragalactic fields
                   5100A central wavelength for Galactic field (Z And)


fibres      : small - 1.6"


Weather conditions: good except for the second night when 80% of the night was
lost to thick clouds. Most of the time was really good and dark.


Seeing            : I think about 1" the first night (judging from the image of
the fiducial star fibre bundles), a little worse the other nights. 


Technical problems: Two occasions AF2 went badly wrong. 
First night a lost fibre, probably caused by
a fibre collision. 2.7 hours lost while engineers recovered the fibre and dealt
with the software error in autofib's brain whereby it thought the fibre was
lost even though it had been disabled. Staff recommended that I reconfigure all
the fields with a 1.75 buffer factor rather than the normal 1.5, so I did this
for all the fields observed on the 2nd and later nights.
Last night, a real fibre collision ended up with one fibre on top of another,
a broken prism on one and one of them wedged in the jaws of the robot gripper.
Took about 2.5 hours to sort out, but worked OK for the rest of the night with
the relevant fibre disabled in the remaining configs.

There was rather more noise on the Tek6 chip than was expected - the noise went
up and down in a random sort of fashion on several-hour timescales. For the
last night Peter Moore succeeded in stabilising the noise to about 8 electrons
and at least it didnt have its wavy pattern any more.


Other: I had no time for on-line data reduction due to the over head of
configuring (and reconfiguring!) fields. I got some great help from Francisco
on the second night configuring problem fields like the SDS2 field, which made
sure that I was well prepared for the rest of the run despite having to
reconfigure everything with a larger buffer size.  There were engineers
available virtually all the time to sort out autofib if it went wrong, (after
the last AF2/WYFFOS run...) and so our technical downtime was fairly small. I
spotted at least one quasar spectrum on the screen in one of the fields from
the last night (and its hard to spot anything on those images) so I think we
should have some good data.


Target fields:
==============

PKS2126  2x1800s
Cl0016   2x1800s
PHL1092  2x1800s
Mkn3     2x1800s

PB5062   2x1800s

MS2137   2x1800s
PHL5200  2x1800s
ZAnd_1   2x1800s
ZAnd_2   1x1800s 1x780s 1x900s (guiding jump caused exposure break)
MS0737   3x1800s

PKS2135  2x1800s
LBQS2212 2x1800s
SDS2     3x1800s
S50836   2x1800s