HiPERCAM: a quintuple-beam, high-speed optical imager on the 10.4-m Gran Telescopio Canarias

TL;DR

HiPERCAM is a high-speed, multi-band optical imager designed for the 10.4-m GTC, enabling deep and rapid imaging of faint and fast-varying astronomical sources across five spectral bands simultaneously.

Contribution

This paper introduces HiPERCAM, a novel quintuple-beam optical imager with high-speed capabilities and enhanced field of view, optimized for the 10.4-m GTC, including its design, performance, and future plans.

Findings

Achieves over 1000 frames per second in high-speed mode

Detects sources down to g_s ~ 23 in 1 second

Provides simultaneous imaging in five optical bands

Abstract

HiPERCAM is a portable, quintuple-beam optical imager that saw first light on the 10.4-m Gran Telescopio Canarias (GTC) in 2018. The instrument uses re-imaging optics and 4 dichroic beamsplitters to record $u_s g_s r_s i_s z_s$ ($320-1060$ nm) images simultaneously on its five CCD cameras, each of 3.1 arcmin (diagonal) field of view. The detectors in HiPERCAM are frame-transfer devices cooled thermo-electrically to 183 K, thereby allowing both long-exposure, deep imaging of faint targets, as well as high-speed (over 1000 windowed frames per second) imaging of rapidly varying targets. A comparison-star pick-off system in the telescope focal plane increases the effective field of view to 6.7 arcmin for differential photometry. Combining HiPERCAM with the world's largest optical telescope enables the detection of astronomical sources to $g_s \sim 23$ in 1 s and $g_s \sim 28$ in 1 h. In this paper we describe the scientific motivation behind HiPERCAM, present its design, report on its measured performance, and outline some planned enhancements.