GRAVITY Wide Science Verification

Published: 22 Feb 2022

GRAVITY dual-feed wide mode allows fringe tracking from a target that is up to 30” away from the science target by using the VLTI Star Separators to separate the beams. This mode augments GRAVITY sky coverage by enabling observations of objects which were too faint for fringe tracking, and without a close (<2") fringe tracker source. Two nights will be offered: one on VLTI-UTs and one on VLTI-ATs, both in mid-June 2022. The proposal submission deadline is 25 March 2022 (same as the Period 110 Call for Proposals) using the Phase 1 tool.

GRAVITY-wide can only deliver spectrally differential observables at the moment (visibilities, phases and closure phases). As no absolute calibration is currently possible, observations with GRAVITY-Wide are simply made of a single SCI Observation Block. More information is available.