MAS January Meeting

Searching for Exoplanets Born Outside the Milky Way

MAS January 2024 Meeting - Bob Aloisi

Over 5500 exoplanets have been found orbiting stars in the Milky Way, with projections that most stars host planets. This poses the question of whether planets also exist orbiting the remnant stars of smaller dwarf galaxies that merged with the Milky Way, and if so, how do they differ from their Milky Way counterparts? VOYAGERS Views of Yore – Ancient Gaia-Enceladus Exoplanet Revealing Survey is a radial velocity search using precision spectrographs to find exoplanets orbiting low metallicity ([Fe/H] from -2.8 to -0.x, Vmag 8 to 10 stars born in the dwarf galaxy Enceladus, which merged with the Milky Way galaxy about 10 Gyr ago. A pool of 22 candidates from Enceladus F, G, and K class stars have been screened using reconnaissance observations from the TRES spectrograph. Precision RV measurements are ongoing over 3 years using the NEID, HARPS-N and CARMENES spectrographs. Ultimately, we hope the survey will lead to a better understanding of when and where in our universe’s history planets – and life – can form.

Bob Aloisi is a 4th year Ph.D. student at the UW Madison. His return to graduate school follows a nearly 30 year career working in consumer products development. Bob’s work on exoplanets makes use of local telescopes such as the Bell Burnell Observatory at Promega, formerly the MAS Oscar Mayer Observatory, formerly the UW Madison Student Observatory.