Cosmic Anisotropy Telescope

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{{Infobox telescope}}

The Cosmic Anisotropy Telescope (CAT) was a three-element interferometer for cosmic microwave background radiation (CMB/R) observations at 13 to 17 GHz, based at the Mullard Radio Astronomy Observatory.{{cite web |url=https://lambda.gsfc.nasa.gov/product/websites/AMI/mrao.cam.ac.uk/telescopes/cat/cat_intro.html |title=CAT - Introduction |work=MRAO |publisher=NASA |access-date=1 June 2025}} In 1995, it was the first instrument to measure small-scale structure in the cosmic microwave background.{{cite press release |url=https://lambda.gsfc.nasa.gov/product/websites/AMI/mrao.cam.ac.uk/telescopes/cat/press_release.html |title=First detailed picture of the early universe |work=MRAO |date=1996 |access-date=1 June 2025}}{{cite journal |last1=Scott |first1=P. F. |last2=Saunders |first2=Richard |last3=Pooley |first3=Guy |last4=O'Sullivan |first4=Créidhe |last5=Lasenby |first5=A. N. |last6=Jones |first6=Michael |last7=Hobson |first7=M. P. |last8=Duffett-Smith |first8=P. J. |last9=Baker |first9=Joanne |display-authors=1 |url=https://iopscience.iop.org/article/10.1086/310000 |title=Measurements of Structure in the Cosmic Background Radiation with the Cambridge Cosmic Anisotropy Telescope |journal=The Astrophysical Journal |volume=461 |issue=1 |pages=L1–L4 |date=April 1996 |doi=10.1086/310000}} When the more sensitive Very Small Array came online in 2000, the CAT was decommissioned and partly dismantled.{{cite web |url=https://lambda.gsfc.nasa.gov/product/websites/AMI/mrao.cam.ac.uk/telescopes/cat/index.html |title=The Cosmic Anisotropy Telescope |work=MRAO |publisher=NASA |access-date=1 June 2025}}