Andy Sheinis

MSE is a massively multiplexed spectroscopic survey facility that will replace the Canada-France-Hawaii-Telescope in the coming decade. This 12-meter telescope, with its 1.5 square degree field-of-view, will observe 18,000 – 20,000 astronomical targets in every pointing from 360 nm through H-band at low/moderate resolution (R=3,000/7,000) and and 360-1000nm at high (R=30,000). A Piezo actuated fiber positioner enables simultaneous full field coverage for both resolution modes.  MSE will unveil the composition and dynamics of the faint Universe and impact nearly every field of astrophysics across all spatial scales, from individual stars to the largest scale structures in the Universe, including (i) the ultimate Gaia follow-up facility for understanding the chemistry and dynamics of the distant Milky Way, including the outer disk and faint stellar halo at high spectral resolution (ii) galaxy formation and evolution at cosmic noon, (iii) derivation of the mass of the neutrino and insights into inflationary physics through a cosmological redshift survey that probes a large volume of the Universe with a high galaxy density. The instrument suite, dedicated to large scale surveys, will enable MSE to collect a massive amount of data: equivalent to a full SDSS Legacy Survey every several weeks. We present an overview of  the MSE science case and an update to MSE. In addition, we present the plan to develop in the near future a Pathfinder instrument at CFHT to fast-track development of the MSE technology as well as provide a dedicated transient followup capability featuring IFU spectroscopy in the visible  mated to high-resolution single object spectroscopy with continuous coverage from 370nm-2.3um.