The VERITAS-Stellar Intensity Interferometry (VSII) survey of Stellar Diameters

TL;DR

The VSII survey used the VERITAS IACT array with enhanced electronics to measure stellar diameters with high precision, covering 39 bright stars and binary systems over 250 hours since 2019.

Contribution

This work demonstrates the application of IACT technology for stellar interferometry, providing high-resolution diameter measurements of bright stars.

Findings

Measured stellar diameters with better than 5% resolution.

Recorded over 250 hours of observations on 39 stars.

Successfully adapted VERITAS for stellar intensity interferometry.

Abstract

The VERITAS Imaging Air Cherenkov Telescope (IACT) array was augmented in 2019 with high-speed focal plane electronics to allow its use for Stellar Intensity Interferometry (SII) observations. Since January 2019, the VERITAS Stellar Interferometer (VSII) recorded more than 250 hours of moonlit observations on 39 different bright stars and binary systems ($m_V < 3.74$) at an effective optical wavelength of 416 nm. These observations resulted in the measurement of the diameters of several stars with better than 5% resolution. This talk will describe the status of the VSII survey and analysis.