Sub-Microarcsecond Astrometry with SIM-Lite: A Testbed-based Performance Assessment

TL;DR

This paper evaluates the performance of SIM-Lite, a high-precision astrometric interferometer, using a testbed to assess systematic errors and demonstrate a sub-0.035 microarcsecond noise floor for narrow-angle measurements.

Contribution

It provides the first detailed testbed-based assessment of SIM-Lite's systematic error limits and confirms its capability for ultra-precise astrometry.

Findings

End-of-mission noise floor below 0.035 microarcseconds for narrow-angle astrometry

Systematic errors are well-controlled in the testbed environment

Demonstrates potential for detecting Earth-like exoplanets and dark matter distribution

Abstract

SIM-Lite is an astrometric interferometer being designed for sub-microarcsecond astrometry, with a wide range of applications from searches for Earth-analogs to determining the distribution of dark matter. SIM-Lite measurements can be limited by random and systematic errors, as well as astrophysical noise. In this paper we focus on instrument systematic errors and report results from SIM-Lite's interferometer testbed. We find that, for narrow-angle astrometry such as used for planet finding, the end-of-mission noise floor for SIM-Lite is below 0.035 uas.