The SOLIS Vector-Spectromagnetograph (VSM)


SOLIS (Synoptic Optical Long-term Investigations of the Sun) is a suite of three innovative instruments that will greatly improve ground-based synoptic solar observations. The main instrument, the Vector Spectro-Magnetograph (VSM), is a compact, high- throughput vector-polarimeter with an active secondary mirror, an actively controlled grating spectrograph, and two high-speed cameras based on silicon-on-CMOS-multiplexer hybrid focal plane arrays. It measures the photospheric magnetic field strength and direction over the full solar disk within 15 minutes using two iron lines at 630 nm. It can also record the longitudinal magnetic flux in the chromosphere and coronal proxies derived from the HeI 1083 nm spectral line.

The VSM has just been assembled and is expected to see first light at a temporary site in Tucson before the end of May. We will present an overview of the instrument, describe its performance, and discuss first results.

SOLIS has been supported by a specific grant from NSF, NSO base funding, NASA/GSFC, and the ONR. The project has also received significant technical assistance from HAO and the Solar and Astrophysics Lab of Lockheed-Martin.

AAS/Solar Physics Division Meeting #34