SuperWASP: The Trials and Tribulations of a
Remote Inauguration Ceremony
Don Pollacco
* (Queen’s University Belfast), Ian
Skillen (ING), Javier Méndez (ING) and the WASP Consortium
It is ironic that
in this technical age we live in there are few professional facilities in
operation that are designed to monitor the sky at optical wavelengths. Historically,
this work has been left to dedicated amateur astronomers often using observatory
grade equipment. Part of the reason for the absence of professional projects
is the lack of reliable equipment and the huge data rates involved. The SuperWASP
facility is an attempt by professionals to join in the exploitation of the
time domain. It is the rapid development of robotic technology and affordable,
but powerful, computing that has made this project feasible.
The main science aims of SuperWASP include the detection of extra-solar
planets (the so-called hot-Jupiters), optical counterparts to Gamma-Ray Bursters
and rapidly moving near-Earth asteroids. While the UK Particle Physics and
Astronomy Research Council (PPARC) provided some seed funding for SuperWASP,
the bulk of the funding came from the Queen’s University Belfast (QUB). Other
contributions came from the Open University, the Royal Society, Andor Technology
and St. Andrews University. The QUB funding became available in March 2002.
Those of you who have been out to La Palma over the last year may have noticed
the appearance of the SuperWASP enclosure on the Roque. In fact avid viewers
of the CONCAM all-sky images noticed that the building was erected during
the day of the 6th July 2003. Shaped like a garage sized shoe box but with
a peculiar stepped-roof, it is sited on the hillside below the JKT towards
the Swedish Solar Telescope. The enclosure is composed of two rooms with the
instrument itself located at the southern end of the building and the control
computers at the other end. During normal operations the roof above the instrument
slides, under hydraulic pressure, onto the computer room end, and the cameras
are exposed to the sky. The SuperWASP cameras are contained within a cradle
and mounted in place of a telescope tube in an equatorial fork mount.
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Figure 1. SuperWASP at dusk on the 27th November
2003 —first light. The WHT dome is in the background (photo courtesy Jens
Moser). [ JPEG | TIFF ]
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Compared to, for example the INT Wide Field Camera, the field of view of
SuperWASP is truly awesome: currently about 1200 times larger. To achieve
this SuperWASP is composed of five cameras each having a dedicated telephoto
lens and CCD detector. The lenses image onto the detector at low angular resolution
(14 arc seconds per pixel) hence allowing a large field of view for the camera.
This design allows us to achieve accurate photometry on bright objects (<1%
for stars brighter than magnitude 13 for a single 30 second integration).
However, with such large angular pixels the sky level is quite bright which
limits the magnitude of objects detected (3σ detection at magnitude 16.5
per 30 second integration). SuperWASP is able to accurately measure the brightness
of millions of stars in a single night.
The equatorial mount, along with the observatory control software, TALON,
is the heart of SuperWASP. TALON controls all observatory functions (e.g.
monitoring the weather station, GPS time service, etc.), as well as indirectly
controlling all CCD cameras via their data acquisition computers. The computer
room is protected by a telecommunications grade air conditioning plant. The
detectors themselves are the 2048×2048 pixel e2v42 CCD devices familiar
to WHT users, but are thermo-electrically cooled. The optics are the now obsolete
Canon 200mm F1.8 telephoto lenses, often described as “the fastest telephoto
lens available”.
After obtaining planning permission on La Palma, construction of the facility
began in June 2003. In July, we erected the enclosure using probably the most
highly qualified labourers available (and the worst paid!) followed by the
associated electrical and communications work. By mid-August we installed
the fork mount and built up the computer systems. By September 2003 we had
completed the first pointing models with the mount and started to build up
the camera cradle —initially with 4 detectors included. Engineering first
light occurred late in the month. After a break for engineering work (and
to give a lecture course) true astronomical first light occurred in late November
2003 —some 21 months after the funding became available. SuperWASP then regularly
obtained data up until Christmas. We had a scheduled break for three months
to address some of the many technical issues highlighted from our operational
month, as well as to re-engineer some of the camera heads. The data from
that period has proved invaluable in debugging the reduction pipeline prior
to commencement of normal operations scheduled for mid-April 2004.
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Figure 2. First light mosaic image of the southern
part of Orion. In this 1 second exposure the horse head nebula and Barnard
loop are clearly visible along with some 35,000 stars. [ JPEG | TIFF ]
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Figure 3. A two chip mosaic of Comet Neat on 15th
May 2004 (courtesy of Alan Fitzsimmons). Wow! [ JPEG
| TIFF ]
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As is common with new instruments we decided to hold an inauguration ceremony
for the facility and it seemed like a good idea to hold this event at the
start of operations on Friday 16th April 2004. However, as the date approached
and with the detectors stuck with DHL in Madrid for several weeks (they arrived
there a few days after the tragic terrorist attacks), we became more concerned
that we may be forced to inaugurate the facility with just the single detector
left on La Palma. Just to compound our problems, the weather on the Roque
had been somewhat unpredictable with a severe cold spell. After several interventions
on our behalf by various bodies, the detectors finally arrived back on the
Roque on Monday 12th April, whereupon we built up the camera cradle. By Wednesday
the weather had turned worse with a blizzard laying some 10 cm of snow overnight.
At 3 pm the day before the inauguration was due to take place we took the
decision to abandon the event at the summit, and after some discussion, to
hold the event at the ING sea-level base. The IAC representatives rearranged
the press and other official matters, and at the same time we rearranged the
social activities.
Tests Thursday morning had shown that, in principle, provided the network
traffic wasn’t too high, we could run SuperWASP remotely from sea level. Thursday
afternoon we reconfigured the observing system to include streaming video
from our internal network camera as well as a view of the building from our
external camera. SuperWASP had always been designed to be able to be run
in this way, but the weather conditions had forced us to attempt this operational
mode several months before we expected to. We were surprised it worked so
well! For the inauguration we would attach a red ribbon to the camera cradle
which would (in principle) fall to the ground as the instrument was moved.
At this time our UK based guests were also arriving, including Professor
Kenny Bell (Pro-Vice-Chancellor at QUB) and Professor Martin Ward (Chair
of the PPARC Science Committee).
Surprisingly the weather on the Roque on the day of the inauguration ceremony
stayed fair but cold. With the remnants of the snow still around and some
ice still on the road we felt vindicated in our decision to move to sea level.
The event itself went almost exactly to plan, culminating with the Mayor of
Garafía moving the cameras and the ribbon falling. This was just as
well: there was no reserve plan, no pre-recorded videos of the instrument
running. The only slight (well amusing) flaw occurred when after the ceremony
the TV cameras asked to repeat the final part of the ceremony during which
the ribbon stubbornly refused to fall until discreetly helped! Ironically
the weather had forced us to remotely inaugurate a robotic instrument —a first
as far as we are aware, and most satisfying given the adverse conditions we
faced at the time.
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Figure 4. A moment of the remote inauguration ceremony
of SuperWASP on 16th April 2004 from ING’s sea-level office in Santa Cruz
de La Palma. [ JPEG | TIFF
]
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SuperWASP has now moved into the operational phase. At the time of writing
the facility is running automatically but not yet robotically. During normal
observing SuperWASP takes 30 second integrations which after allowing for
readout and telescope movements results in, on average, about one integration
every 60 seconds (for each camera). Each detector produces an image of 8.3
MB in size, hence an average night with the current system results in about
25–30 GB of science and calibration data. At the end of the night this is
written to DLT tape and shipped back to QUB for analysis. After reduction
the brightness measurements are stored in a database hosted (and funded) by
Leicester University (LEDAS). We are currently gaining valuable information
on how to run this instrument efficiently with a view to running a limited
(attended) robotic mode in late 2004.
New funding, obtained by Keele and St. Andrews Universities, will allow
the full expansion of SuperWASP (8 camera units giving a field of view of
some 500 square degrees), as well as the construction of a clone facility
destined for SAAO. In this configuration SuperWASP will be able to image
the available part of the celestial sphere in only 67 pointings (with these
optics), while the visible sky can be surveyed in less than 40 minutes. Thus
SuperWASP can efficiently monitor the whole sky. Do not be deceived: it may
be small but it’s powerful!
The WASP Consortium is composed of astronomers from the UK Universities
of Belfast, Cambridge, Keele, Leicester, Open, St. Andrews as well as the
IAC and ING. We are indebted and grateful to the staff of both the IAC and
ING for their enthusiasm and support for this project, and look forward to
a fruitful collaboration in the months and years ahead.
¤
*Email contact: Don Pollacco (
D.Pollacco@qub.ac.uk)