A SONG for New Mexico: Observing the interiors of stars

A detailed understanding of stars underpins much of astrophysics. Stars are the most fundamental astrophysical objects, they are the basic constituents of galaxies, and, to a large extent, the overall properties of the universe are controlled by their evolution. Stars are huge balls of gas, and turbulent motions within them generate sound waves that cause the majority of them to wobble and ring like bells. The measurement and analysis of these acoustic oscillations is the only way to peer into the interior of a star. We are in the beginning stages of an NSF project to acquire and assemble a telescope and spectrograph instrument that will be part of a world-wide network dedicated to ‘listening’ to stars 24 hours per day. Constant monitoring is the only way to directly observe the workings of their interiors. The Stellar Observations Network Group, or SONG, is a planned network of 1-meter, robotic telescopes that will perform continuous, high-precision radial-velocity measurements of bright stars for asteroseismology and studies of exoplanet host stars. The network has three sites that are either operating (SONG-Tenerife) or will soon be operating (SONG-Australia and SONG-China). This presentation describes the planning and the research activities to be enabled by a fourth node - SONG in New Mexico - led by NMSU Astronomy and located at its Apache Point Observatory.