NEO Characterization Science Case For a Low Resolution Spectrograph

TL;DR

This paper advocates for a low-resolution spectrograph on small telescopes to enhance the characterization of Near Earth Objects, enabling better data collection on their physical properties.

Contribution

It proposes a specific instrument design for low-resolution spectroscopy and imaging to improve NEO data acquisition on small telescopes.

Findings

Design of a low-resolution spectrograph with R~30 for NEO studies.

Potential upgrade to include near-IR channel extending to 2.5 μm.

Optimized optical throughput for faint object observation.

Abstract

Near Earth Asteroids (NEAs) and dead comets comprise the vast majority of the population of Near Earth Objects (NEOs) detected to date. Less is known of their physical properties than of the much larger population of main-belt asteroids. Due to the faintness and short duration of visibility of NEOs, many characterization studies use broadband filters in 3 to 8 colors for taxonomic classification and to study surface chemical composition. A spectrograph with low spectral resolution R~30 used in a campaign or a continuing program on a small telescope (1-2m class) would vastly improve the quantity and quality of data on NEOs. The proposed baseline instrument would work in the visible using a CCD detector, with a possible upgrade to include a second, near-IR (NIR) channel extending coverage to 2.5 \mum or beyond. The optical design needs to optimize overall optical throughput to permit observation of the faintest possible objects on small telescopes at acceptable signal-to-noise (S/N) ratios. An imaging mode to obtain accurate same-night broadband photometry would be highly desirable.