Astrophysics Group

Cavendish Laboratory

COAST Current Status


COAST was designed in 1986 and construction had begun by 1988. The first stellar fringes were obtained in June 1991. Tentative closure phase was obtained at the start of 1993, and by later that year results were convincing. The first images were made in September 1995.

The first infrared stellar fringes were observed on 1 January 1995, when measurements were taken of alpha Tauri at 1.3 microns. The first convincing non-zero closure phases were measured on 25 October 1997, on the binary star Capella. We obtained sufficient data to reconstruct the first infrared image from an aperture synthesis array.

More recent developments are as follows:

The University of Cambridge and New Mexico Tech signed a Memorandum of Understanding formalising their collaboration to build the Magdalena Ridge Observatory Interferometer.
COAST was operated remotely for the first time (from a building 100m from the beam-combining laboratory).
The COAST team announced a new partnership with the Magdalena Ridge Observatory Consortium, to design and build a $40M optical/IR interferometer, sited at the Magdalena Ridge Observatory in New Mexico.
The North telescope of the COAST array was moved to a new foundation, further to the North, making the longest baseline 67 metres.
A fifth telescope was sited on the Southwest arm of the COAST array.

The current status

COAST is no longer operated, but the beam combining building is used as a stable laboratory for testing of precision opto-mechanical systems, for example the delay line trolleys for MROI.

The COAST array has five telescopes, and the longest baseline is 67 metres (foundations are in place for a 100m baseline, which was never commissioned).