Annual Report 2011 Max Planck Institute for Astronomy

IV. Instrumental Developments and Projects
Here we report on further activities mainly belonging
to our instrumentation projects and related technical
developments. Since the number of ongoing projects is
rather large, we are only presenting a selection of our
current activities. Since this selection varies over the
years, we encourage the reader to have also a look into
other Annual Reports of MPIA.
IV.1 The Pan-StarrS1 surveys and
some early results
The Pan-StarrS1 project is the first of a new generation
of imaging survey telescopes of “extremely
large” figure of merit and powerful data processing
pipeline. Pan-StarrS stands for the PANoramic Survey
Telescope And Rapid Response System, and its first
unit out of four planned is called Pan-StarrS1 (or
PS1 for short) and is located on Haleakala in Hawaii.
MPIA and its other partner institutes of the MPG and
elsewhere founded in 2006 the PS1 Science Consortium
to support the telescope operations and conduct the PS1
surveys; and to organise the scientific work. As a major
contributor, MPIA enjoys full access rights and leads
several scientific areas called “key projects”. In addition,
the institute may offer access rights to six German
scientists. We used this opportunity to strengthen our
scientific ties to university colleagues. During the commissioning
phase, MPIA contributed to the characterisation
of the telescope performances. After almost a
year of further system optimisation and partial scientific
operations, the telescope and camera were deemed
ready for regular survey operations, which started in
April 2010.
An extremely large camera
The PS1 project features a fast, 1.8-m telescope, with
an average overhead of 13 seconds between two exposures;
the largest-ever built camera with 1.4-Gigapixel,
7-square degrees field of view, and sensitivity between
0.35 and 1.02 μm; and a dedicated pipeline capable of
reducing the night’s observations and delivering catalogues
before tea time. The pipeline also produces advanced
data products such as stacked images, which are
the sum of all the images observed over a given sky area,
and differential imaging, which in contrast one subtracts
the most recent image to a template of the field, in order
to easily detect variable sources, or new astronomical objects
such as supernovae.
The large field of view of the camera, six times the
Full Moon in diameter, and 35 times in solid angle, allows
to cover the whole sky visible from Haleakala with
about 4300 telescope pointings. After 1.5 years of regular
survey operations, PS1 has covered a few times the
sky North of DEC –30 (3π-steradian survey) in five
optical bands. This is twice the area covered by the Sloan
Digital Sky Survey (SDSS), a PS1 precursor and one of
most successful astronomical projects ever, over its decade
of imaging operations.
The photometric calibration is on-going, either against
SDSS photometry or using PS1 overlapping observations
with “übercalibration”. Proper motions calculated
using 2MASS as the first epoch have a typical accuracy
of 10 mas/yr.
In addition, shallower imaging is obtained in parallel
to the CPG1 observations, at low spatial resolution.
Fig. IV.1.1: NGC 894 in gri colours, in the Medium Deep Field 01.
Credit: N. Metcalfe et al.
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