ACAM was designed to exploit better the wide field of view
available at the WHT Cassegrain focus.
ACAM's predecessor, the
aux-port camera, was simply a CCD with a
filter wheel in front of it (no optics) offering
a field of view 1.8 arcmin across.
The filter wheel (6 slots) accommodated only 50-mm filters,
and changing the filters in the wheel meant removing the
cryostat and filter-wheel box from the telescope.
Nevertheless, the aux-port camera scored several scientific firsts,
including: the first detection of gravitational lensing;
identification of the companion star to Tycho Brahe's 1572 supernova;
and first detection of the progenitor star of normal type-II-P supernovae
(see above link for details).
ACAM was designed
to provide a much wider field of view, without compromising
significantly the throughput, image quality and wavelength coverage
provided by the aux-port camera.
At the same time,
the opportunity was taken to allow use of a wider range of
filter size and types, to make filter changes much more
straightforward, and to provide low-resolution spectroscopy.
It's expected that ACAM will be used for a broad range of high-impact
science programmes requiring rapid response (e.g. supernovae,
gamma-ray bursts), or awkward scheduling (e.g.
exoplanet transits), or the use of specialised filters
(e.g. narrow-band Hα imaging of low-redshift galaxies).
- 2006 March - project formally initiated
- 2006 November - conceptual design review (formally passed
- 2007 November - final design review
- 2007 December - contract for optics placed with ICOS
- 2008 November - two lenses damaged during coating in the UK,
commissioning delayed 3 months
- 2009 March - another lens damaged during coating, commissioning
delayed 2 months
- 2009 June - first light for imaging and spectroscopy, and first
scheduled science runs
The names of the people involved in the project
are given on the