A potential new method for determining the temperature of cool stars

TL;DR

This paper proposes a new method for determining the effective temperatures of cool stars, specifically M dwarfs, using high-resolution mid-infrared spectra that contain water vapor transitions sensitive to temperature changes.

Contribution

The study identifies specific water vapor transitions in mid-infrared spectra that can serve as reliable indicators for measuring the temperatures of low-mass stars.

Findings

At least 10 water transitions are sensitive to 25 K temperature changes.

High-resolution spectra can reveal pure rotational water lines useful for temperature estimation.

36 water transitions were confirmed and assigned in the spectra.

Abstract

We present high resolution (R = 90,000) mid-infrared spectra of M dwarfs. The mid infrared region of the spectra of cool low mass stars contain pure rotational water vapour transitions that may provide us with a new methodology in the determination of the effective temperatures for low mass stars. We identify and assign water transitions in these spectra and determine how sensitive each pure rotational water transition is to small (25 K) changes in effective temperature. We find that, of the 36 confirmed and assigned pure rotational water transitions, at least 10 should be sensitive enough to be used as temperature indicators.