ING Annual Report 1995/96
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Chapter 2 - New Instrumentation and Enhancements
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4 - Telescope Operation
Chapter 3
Telescope Performance
USE OF TELESCOPE TIME
The following tables show for
each telescope how the nights in Semesters A and B were allocated between
PATT, CAT, the international collaborative scheme, scheduled stand-downs,
and service and discretionary nights. Stand-downs are periods of major
maintenance or instrumental commissioning. Discretionary nights are used
partly for minor enhancements and calibration and partly for astronomy
(for example, as compensation for breakdowns or for observations of targets
of opportunity). The aim of the ING Service Programme is to provide astronomers
with a way to obtain small sets of observations, which would not justify
a whole night or more of telescope time. For each telescope and instrument
several nights per month are set aside especially for this purpose. During
those nights, La Palma support astronomers perform observations for several
service requests per nights.
The British and Dutch time is allocated
by PATT, and CAT is responsible for the Spanish time. The ratio of PATT
: CAT : international time is nominally 75 : 20 : 5. This ratio is
monitored and small differences in these proportions in any one year are
corrected over a number of observing seasons.
The way the available observing
time on the ING telescopes has been shared in 1995 and 1996 is summarised
in the following tables.
Use of Telescope
Time in Semesters 95A+95B
|
WHT |
INT |
JKT |
|
Nights |
% |
Nights |
% |
Nights |
% |
PATT |
201 |
55.1 |
224 |
61.4 |
248 |
68.0 |
CAT |
60 |
16.4 |
67 |
18.4 |
69 |
18.9 |
ITP |
15 |
4.1 |
16 |
4.4 |
16 |
4.4 |
Service |
24 |
6.6 |
21 |
5.7 |
8 |
2.2 |
Stand-down |
43 |
11.8 |
18 |
4.9 |
10 |
2.7 |
Discretionary |
22 |
6.0 |
19 |
5.2 |
14 |
3.8 |
Total |
365 |
100.0 |
365 |
100.0 |
365 |
100.0 |
Use of Telescope
Time in Semesters 96A+96B
|
WHT |
INT |
JKT |
|
Nights |
% |
Nights |
% |
Nights |
% |
PATT |
200.5 |
54.8 |
224 |
61.2 |
242 |
66.1 |
CAT |
65 |
17.7 |
70 |
19.1 |
71 |
19.5 |
ITP |
16 |
4.4 |
16 |
4.4 |
16 |
4.4 |
Service |
27.5 |
7.5 |
19 |
5.2 |
11 |
3.0 |
Stand-down |
35.5 |
9.7 |
24 |
6.6 |
13 |
3.5 |
Discretionary |
21.5 |
5.9 |
13 |
3.5 |
13 |
3.5 |
Total |
366 |
100.0 |
366 |
100.0 |
366 |
100.0 |
USE OF INSTRUMENTATION
The tables below show for each telescope the
number of nights for which the different instruments were used. Stand-down
periods are excluded. The abbreviations are explained in Appendix B and
the Glossary. "Other" includes all instrumentation which is not common-user.
ISIS and UES were again the most popular instruments
on the WHT. On the INT the most used instruments were, as in previous years,
the prime focus CCD camera and the IDS spectrograph. On the JKT, the dominant
instrument remains the CCD camera.
Use of Instrumentation
in Semesters 95A+95B
|
WHT
|
|
ISIS |
LDSS |
Taurus |
UES |
WYFFOS |
Prime Focus |
MARTINI |
Autofib |
GHRIL |
WHIRCAM |
Other |
Total |
Nights |
147 |
28 |
14 |
70 |
22 |
18 |
12 |
6 |
11 |
16 |
14 |
358 |
% |
41.0 |
7.8 |
3.9 |
19.6 |
6.1 |
5.0 |
3.3 |
1.8 |
3.1 |
4.5 |
3.9 |
100.0 |
|
INT |
|
PFC |
IDS |
Other |
Total |
Nights |
131 |
209 |
7 |
347 |
% |
37.8 |
60.2 |
2.0 |
100.0 |
|
JKT |
|
CCD |
RBS |
Other |
Total |
Nights |
299 |
35 |
21 |
355 |
% |
84.2 |
9.9 |
5.9 |
100.0 |
Use of Instrumentation
in Semesters 96A+96B
|
WHT
|
|
ISIS |
LDSS |
Taurus |
UES |
WYFFOS |
Prime Focus |
MARTINI |
Autofib |
GHRIL |
WHIRCAM |
Other |
Total |
Nights |
105 |
28 |
31 |
69 |
40 |
22 |
9 |
3 |
14 |
26 |
15 |
362 |
% |
29.0 |
7.7 |
8.5 |
19.1 |
11.0 |
6.1 |
2.5 |
0.9 |
3.9 |
7.2 |
4.1 |
100.0 |
|
INT |
|
PFC |
IDS |
Other |
Total |
Nights |
114 |
209 |
33 |
356 |
% |
32.0 |
58.7 |
9.3 |
100.0 |
|
JKT |
|
CCD |
RBS |
WFC |
PP |
Other |
Total |
Nights |
273 |
36 |
8 |
8 |
28 |
353 |
% |
77.3 |
10.2 |
2.3 |
2.3 |
7.9 |
100.0 |
TELESCOPE RELIABILITY
During 1995 and 1996 operation of telescopes
at ING continued to be very satisfactory with time lost due to technical
faults at low levels averaging 2.8% for the William Herschel Telescope,
2.7% for the Isaac Newton Telescope, and 2.4% for the Jacobus Kapteyn Telescope.
No single particular problem was responsible for the remaining technical
down time.
The following plots show for each telescope the
proportion of scheduled observing time lost to technical failures and bad
weather. All PATT, CAT and international collaborative nights are included
when common-user instrumentation was mounted; stand-downs and discretionary
time are excluded. Percentages of technical downtime for JKT were: 2.9%
(95A), 1.5% (95B), 3.4% (96A), and 2.7% (96B).
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Chapter 2 - New Instrumentation and Enhancements
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4 - Telescope Operation
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