Searching for Fast Optical Transients using VERITAS Cherenkov Telescopes

TL;DR

This paper explores using VERITAS Cherenkov telescopes, traditionally for gamma-ray astronomy, to detect fast optical transients on microsecond timescales, leveraging their large collecting area and dedicated instrumentation.

Contribution

It introduces the VERITAS Transient Detector (TRenDy), a novel multi-channel photometer designed for fast optical transient detection with Cherenkov telescopes.

Findings

Demonstrated detection of a star passing through the field of view

Captured the optical light curve of a pulsar

Showed feasibility of using Cherenkov telescopes for fast optical transient detection

Abstract

Astronomical transients are intrinsically interesting things to study. Fast optical transients (microsecond timescale) are a largely unexplored field of optical astronomy mainly due to the fact that large optical telescopes are oversubscribed. Furthermore, most optical observations use instruments with integration times on the order of seconds and are thus unable to resolve fast transients. Current-generation atmospheric Cherenkov gamma-ray telescopes, however, have huge collecting areas (e.g., VERITAS, which consists of four 12-m telescopes), larger than any existing optical telescopes, and time is typically available for such studies without interfering with gamma-ray observations. The following outlines the benefits of using a Cherenkov telescope to detect optical transients and the implementation of the VERITAS Transient Detector (TRenDy), a dedicated multi-channel photometer based on field-programmable gate arrays. Data are presented demonstrating the ability of TRenDy to detect transient events such as a star passing through its field of view and the optical light curve of a pulsar.