The Colorado Ultraviolet Transit Experiment (CUTE): a dedicated cubesat mission for the study of exoplanetary mass loss and magnetic fields

Abstract

The Colorado Ultraviolet Transit Experiment (CUTE) is a near-UV (2550 - 3300 angstrom) 6U cubesat mission designed to monitor transiting hot Jupiters to quantify their atmospheric mass loss and magnetic fields. CUTE will probe both atomic (Mg and Fe) and molecular (OH) lines for evidence of enhanced transit absorption, and to search for evidence of early ingress due to bow shocks ahead of the planet's orbital motion. As a dedicated mission, CUTE will observe greater than or similar to 60 spectroscopic transits of hot Jupiters over a nominal seven month mission. This represents the equivalent of > 700 orbits of the only other instrument capable of these measurements, the Hubble Space Telescope. CUTE efficiently utilizes the available cubesat volume by means of an innovative optical design to achieve a projected effective area of similar to 22 cm(2), low instrumental background, and a spectral resolving power of R similar to 3000 over the entire science bandpass. These performance characteristics enable CUTE to discern a transit depth of less than or similar to 1% in individual spectral absorption lines. We present the CUTE optical and mechanical design, a summary of the science motivation and expected results, and an overview of the projected fabrication, calibration and launch timeline.