Current Status of the WASP Project

1
WASP0 A wide field CCD search for extra solar
planets. Instrumentation, data analysis and
preliminary results D. Mislis1, S. Pyrzas1, E.
Harlaftis2,, R. A. Street3, K. Horne4, D.
Pollacco3, J. H. Seiradakis1, S. R. Kane4, T.
Lister4, A. Collier Cameron4, W.I. Clarkson4 1
University of Thessaloniki, Department of
Physics, Section of Astrophysics, Astronomy and
Mechanics, GR-541 24 Thessaloniki, Greece 2
National Observatory of Athens, Institute of
Space Applications and Remote Sensing, P.O. Box
20048, GR-11810 Athens, Greece 3 Queen's
University of Belfast, School of Physics, APS
Division, Belfast, BT7 1NN, UK 4 University of St
Andrews, School of Physics Astronomy, North
Haugh, St Andrews, Fife, KY16 9SS, UK Passed
away, 13 February 2005
To the memory of Emilios
ABSTRACT
PLANET HUNTING
We present the observing strategy, the method of
analysis and first results from the
WASP0-project, with data taken at the Kryonerion
Astronomical Station of the National Observatory
of Athens, in 2002. WASP0 (Wide Angle Search for
Planets) is a project aiming to discover
extrasolar planets using the transit method.
Besides extrasolar planets, the project is
suitable for detecting new variable stars, novae,
asteroids, etc. For the reduction we used the
'SuperWASP pipeline' developed for this specific
purpose by the University of St. Andrews and
Queens University, UK, with in situ modifications
for our computing facilities.
We search for planets using the Hunter3 code
developed for this project. The code fits a
number of models to the data., searching a four
dimensional space, parametrized by (a) the
position of the event, the duration, the depth of
the transit and the slope of the transit curve.
We fit all possible theoretical transit models in
the light curves of all 25 000 stars in the field
and compare the standard deviation of the data
before and after subtracting the fitted curve. If
the standard deviation is below a certain
threshold, we call it a suspect-transit. Then we
fit the same model to the light curves from the
same star in other nights. If in one more night
we find a suspect-transit with the same model, we
call it real transit. In this way, we perform 7.1
trillion different combinations in the light
curves of the stars in our field. In order to
test our technique and the Hunter3 code, we
observed and detected the well known planet,
HD209458, under full moon conditions.
OBSERVATIONS AND
The observations were undertaken at Kryonerion
Astronomical Station, Greece, with the WASP0
Instrument. WASP0 is a wide-field (9), 6.3cm
aperture F/2.8 Nikon camera lens, equipped with
an Apogee-10 CCD detector. The detector is a
2K2K chip with 16? pixels, built by Don Pollacco
at Queen's University, Belfast. The Hyades Open
Cluster was observed for 20 nights over a period
of three months in winter 2002. The observed
field contained about 25 000 stars to the
limiting magnitude of our equipment. Between 80
and 120 photographs were taken every night,
depending on the weather conditions.
HD209458
FIRST STAGE ANALYSIS
We used the Super Wasp pipeline to reduce the
data. The pipeline estimates the fluxes,
coordinates, standard deviation, RMS errors and
air-mass of each star in the field.
Apogee 10 CCD from Kryonerion Observatory (Greece)
VARIABLE STARS IN THE HYADES FIELD
The variable stars exhibit the highest standard
deviation among all stars. Therefore, they are
easily detected by studying the stars with the
highest standard deviation. We have discovered
about 10 new variable stars up to now, none of
which appear in the SIMBAD database. We have
studied both the light curves and the
periodograms of the new stars, some of which are
shown below. The analysis is still underway.
A new extra solar planet?
A NEW EXTRA SOLAR PLANET?
Data for the suspected new extra solar planet in
the Hyades open cluster This graphs above show
the first suspect planets discovered by the
transit method from observations with the WASP0
camera from Greece. The transit was found in two
nights. The time between the two transits define
the period (or multiples of the period). It was
not detected in the data of other nights. This
sets rigid constraints to the period of the
transit. If it is a real extra solar planetary
system, we can derive some useful information
about the system.
Name lc1110-0049570 RA 04h
14m 05.09s Dec 21 02
37.15 Radius 3.21 RJ

Period 4.956 days Depth of
transit 0.021 mag Duration of Transit
32 min Radius of orbit 0.0826
AU Inclination of orbit, i
82.35 Possibility of transit detection
6.7 Velocity 181.93 km/s
RMS vs Mean Magnitude from Hyades field. The
variable stars are those with the highest
distance from average linear plot
We present the light-curves of 3 new variable
stars in the Hyades open cluster and the
periodogramms of 2 of them. In the graph to the
left, the light curve of a new Algol-type
(binary) system is presented. In the bottom
graphs the light curves and the periodograms of
two d-Scuti type stars is depicted.
FUTURE WORK
We plan to investigate the suspect extra solar
planet, using small or medium size telescopes,
equipped with more sensitive detectors and, in
particular, with spectroscopic capabilities. Foll
owing these first results from the WASP0
prototype, we plan to continue working towards
the detection of new variable stars and extra
solar planets. We shall try to make the Hunter3
code more intelligent to fit planet transits with
higher probability to detect physical planetary
systems. We shall apply it in data that we
already have from the SUPER WASP and WASP0
archive.
ACKNOWLEDGMENTS
The authors would like to thanks D.J. Christian
(Belfast (Open University), N.A. Evans (Keele),
A. Fitzsimmons (Belfast), C.A. Haswell (Open
University), C. Hellier (Keele), S.T. Hodgkin
(Cambridge), F.P. Keenan (Belfast), A.J. Norton
(Open University), R. Ryans (Belfast), I. Skillen
(ING) , R.G. West (Leicester), P.J. Wheatley
(Leicester), V. Manimanis and K. Gazeas
(University of Athens), K. Stathoulis (Financial
Technologies SA , Athens), G. Dimou (National
Observatory of Athens), E. H. Haralabidi
(Thessaloniki)