MYSTIC: Michigan Young STar Imager at CHARA

TL;DR

MYSTIC is a new K-band, cryogenic, 6-beam interferometric instrument at CHARA designed to image disks around young stars, utilizing advanced fiber optics and a near-photon-counting detector to study planet formation.

Contribution

The paper introduces the design of MYSTIC, a novel interferometric instrument with enhanced capabilities for imaging young star disks and supporting multiple telescope modes.

Findings

Design of a cryogenic, 6-beam combiner for CHARA

Implementation of a near-photon-counting detector (SAPHIRA)

Support for 4-telescope mode with VLTI-GRAVITY optics

Abstract

We present the design for MYSTIC, the Michigan Young STar Imager at CHARA. MYSTIC will be a K-band, cryogenic, 6-beam combiner for the Georgia State University CHARA telescope array. The design follows the image-plane combination scheme of the MIRC instrument where single-mode fibers bring starlight into a non-redundant fringe pattern to feed a spectrograph. Beams will be injected in polarization-maintaining fibers outside the cryogenic dewar and then be transported through a vacuum feedthrough into the ~220K cold volume where combination is achieved and the light is dispersed. We will use a C-RED One camera (First Light Imaging) based on the eAPD SAPHIRA detector to allow for near-photon-counting performance. We also intend to support a 4-telescope mode using a leftover integrated optics component designed for the VLTI-GRAVITY experiment, allowing better sensitivity for the faintest targets. Our primary science driver motivation is to image disks around young stars in order to better understand planet formation and how forming planets might influence disk structures.