[P-EM11] Frontiers in solar physics

[PEM11-01] NASA's Polarimeter to Unify the Corona and Heliosphere (PUNCH) mission

★Invited Papers

*Craig Edward DeForest¹, Sarah Gibson², Ronnie Killough¹, Will Wells¹, Matt Beasley¹, Robin Colaninno³, Glenn Laurent¹, Group the PUNCH Team (1.Southwest Research Institute, 2.High Altitude Observatory, 3.U.S. Naval Research Laboratory)

The Polarimeter to Unify the Corona and Heliosphere is a wide-field imaging constellation to view the outer solar corona and the solar wind as a single, unified system in three dimensions. The space assets are four small satellites, each well under 100kg, in Sun-synchronous 6am/6pm low Earth orbit. Each satellite carries a single instrument: one Narrow Field Imager (NFI) and three Wide Field Imagers (WFIs) that work together as a single "virtual coronagraph" with a field of view extending between 1.5° and 45° from the Sun in all directions. The constellation collects one polarized image set of the inner heliosphere, every four minutes throughout the mission. The data are merged and background-subtracted on the ground, and published as (B,pB) polarized image pairs. The main data product is 4k x 4k mosaic images, 90° across, in azimuthal-equidistant projection with 3 arcmin spatial resolution. Photometric sensitivity is as low as a few x 10^-18 solar brightness units, when averaged over one square degree of sky for a single image set. Polarimetry is used to locate features in three dimensions. The mission was scheduled to launch at the end of February, 2025 and be in late commissioning during the jpGU spring meeting. We will present the science objectives; additional science enabled by PUNCH; and a technical overview of the mission, including "first light" images from the calibration sequences taken earlier in commissioning.