Veloce Rosso: Australia's new precision radial velocity spectrograph

TL;DR

Veloce Rosso is a highly stable, cost-effective spectrograph designed for precise radial velocity measurements of Sun-like and M-dwarf stars, achieving sub-meter per second accuracy for exoplanet detection.

Contribution

It introduces innovative low-cost design features and advanced calibration methods to enhance precision in a compact, stable spectrograph for the AAT.

Findings

Achieves <1 m/s radial velocity precision.

Maintains thermal stability of +/-0.01 K.

Operates effectively over 580-950 nm wavelength range.

Abstract

Veloce is an ultra-stable fibre-fed R4 echelle spectrograph for the 3.9 m Anglo-Australian Telescope. The first channel to be commissioned, Veloce 'Rosso', utilises multiple low-cost design innovations to obtain Doppler velocities for Sun-like and M-dwarf stars at <1 m/s precision. The spectrograph has an asymmetric white-pupil format with a 100-mm beam diameter, delivering R>75,000 spectra over a 580-950 nm range for the Rosso channel. Simultaneous calibration is provided by a single-mode pulsed laser frequency comb in tandem with a traditional arc lamp. A bundle of 19 object fibres provides a 2.4" field of view for full sampling of stellar targets from the AAT site. Veloce is housed in dual environmental enclosures that maintain positive air pressure at a stability of +/-0.3 mbar, with a thermal stability of +/-0.01 K on the optical bench. We present a technical overview and early performance data from Australia's next major spectroscopic machine.