CASTOR (spacecraft)


The Cosmological Advanced Survey Telescope for Optical and UV Research is a proposed space telescope mission led by the Canadian Space Agency. With its 1-meter diameter primary mirror, CASTOR would provide imaging capabilities in the ultraviolet and blue-optical regions at a spatial resolution similar to that of the Hubble Space Telescope, but over an instantaneous field of view about 100 times larger. CASTOR was selected as Canada's highest priority for space astronomy in the 2020s in the 2020 Long Range Plan for Canadian Astronomy.

Description

CASTOR will complement the upcoming Nancy Grace Roman Space Telescope, Euclid space telescope, and Vera C. Rubin Observatory. These three major wide-field imaging facilities will not have access to the UV portion of the electromagnetic spectrum. CASTOR has been specifically designed to provide this missing capability, with high sensitivity and observing efficiency at UV and blue-optical wavelengths.
Using dichroics, CASTOR would enable simultaneous imaging of three bandpasses over an instantaneous field of view of 0.25 square degrees. In addition to its imaging capabilities, CASTOR will also be equipped with additional instruments enabling high-precision photometry for the monitoring of bright targets, as well as two spectroscopic modes: low-spectral-resolution slitless spectroscopy over the entire imaging field and configurable DMD spectroscopy to provide intermediate resolution spectra in the UV in a parallel field.

Objectives

Specific science drivers of CASTOR include: