Stellar Spectroscopy in the Near-infrared with a Laser Frequency Comb

TL;DR

This paper presents a new infrared radial velocity spectroscopy method using a laser frequency comb, achieving high precision to detect potentially habitable exoplanets around M-dwarfs.

Contribution

It introduces a laser frequency comb calibration technique for infrared spectrographs, enabling sub-10 cm/s precision in stellar RV measurements.

Findings

Achieved <10 cm/s instrument precision.

Stellar RVs approaching 1 m/s.

Potential to discover habitable zone exoplanets.

Abstract

The discovery and characterization of exoplanets around nearby stars is driven by profound scientific questions about the uniqueness of Earth and our Solar System, and the conditions under which life could exist elsewhere in our Galaxy. Doppler spectroscopy, or the radial velocity (RV) technique, has been used extensively to identify hundreds of exoplanets, but with notable challenges in detecting terrestrial mass planets orbiting within habitable zones. We describe infrared RV spectroscopy at the 10 m Hobby-Eberly telescope that leverages a 30 GHz electro-optic laser frequency comb with nanophotonic supercontinuum to calibrate the Habitable Zone Planet Finder spectrograph. Demonstrated instrument precision <10 cm/s and stellar RVs approaching 1 m/s open the path to discovery and confirmation of habitable zone planets around M-dwarfs, the most ubiquitous type of stars in our Galaxy.