The Near Ultraviolet Transient Surveyor (NUTS): An ultraviolet telescope to observe variable sources

TL;DR

NUTS is a small, wide-field UV telescope designed for space-based observation of transient phenomena like supernovae and flare stars, enabling exploration of brighter UV sky regions inaccessible to larger missions.

Contribution

This paper introduces the design, fabrication, and calibration of NUTS, a novel small satellite UV telescope with wide-field imaging for transient source observation.

Findings

Successful design and assembly of the NUTS instrument.

Calibration and environmental testing underway.

Potential to observe bright UV transients previously inaccessible.

Abstract

Observing the ultraviolet (UV) sky for time-variable phenomena is one of the many exciting science goals that can be achieved by a relatively small aperture telescope in space. The Near Ultraviolet Transient Surveyor (NUTS) is a wide-field ($3^\circ$) imager with a photon-counting detector in the near-UV (NUV, 200-300 nm), to be flown on an upcoming small satellite mission. It has a Ritchey-Chretien (RC) telescope design with correction optics to enable wide-field observations while minimizing optical aberrations. We have used an intensified CMOS detector with a solar blind photocathode, to be operated in photon-counting mode. The main science goal of the instrument is the observation of transient sources in the UV, including flare stars, supernovae, and active galactic nuclei. NUTS's aperture size and effective area enable observation of relatively unexplored, brighter parts of the UV sky which are usually not accessible to larger missions. We have designed, fabricated, and assembled the instrument, and the final calibrations and environmental tests are being carried out. In this paper, we provide the scientific motivation and technical overview of the instrument and describe the assembly and calibration steps.