MINERVA-Australis

Lore & Background

MINERVA-Australis was designed as a southern hemisphere counterpart to the northern MINERVA array, with the primary mission of supporting observations by NASA's Transiting Exoplanet Survey Satellite (TESS), launched in April 2018. The facility provides dedicated follow-up and characterisation of newly discovered exoplanets, and also pursues targets of opportunity, extends the baseline of the Anglo-Australian Planet Search program, and collects time-series data on request from partner institutions. The project's principal investigator is USQ astronomer Rob Wittenmyer, leading a consortium including UNSW Australia, Nanjing University, University of California Riverside, MIT, George Mason University, University of Louisville, University of Texas at Austin, and University of Florida.

The facility currently uses four PlaneWave 0.7 meter telescopes with corrected Dall-Kirkham optics and one ASA 0.8 meter telescope with all-reflecting Ritchie-Chretien optics. The CDK telescopes have two ports, allowing simultaneous spectroscopic or photometric observations on the same target. The telescopes are connected by optical fibre to a stabilised echelle spectrograph (R = 75,000, covering 480–630 nm) designed by KiwiStar Optics. Prior to 2020, simultaneous calibration used a Thorium-Argon lamp; after 2020, the source is a Tungsten slit-flat lamp backlighting an iodine cell. Photometric work uses back-illuminated CMOS sensors such as the ASI6200, offering an effective field of view greater than 20 arcminutes.

Reader's Guide

MINERVA-Australis obtains radial velocity observations with precision approaching 1 meter/second, enabling direct determination of the masses of planet candidates discovered by TESS. Its fast-cadence multispectral photometric observations achieve precision of 1 part per thousand for stars as faint as 12th magnitude, allowing detection of transiting Earth-size planets around stars with stable flux. Transit light curve analysis yields orbital period, orbit size, and planet radius relative to the host star; combined with radial velocity and spectroscopy during transit, the data reveal planet mass and orbital inclination. By 2026, observations from the array contributed to the discovery of more than 40 exoplanets through global collaboration. The facility's design, with multiple telescopes and a stabilised spectrograph, provides dedicated ground-based follow-up critical for confirming and characterising TESS planet candidates in the southern hemisphere.

Did You Know?

• MINERVA-Australis saw first light in quarter two 2018 and was officially launched on 23 July 2019.
• The facility uses four 0.7-meter CDK telescopes and one 0.8-meter Ritchie-Chretien telescope.
• Its spectrograph covers wavelengths 480–630 nm with a resolving power of R = 75,000.