Feasibility of observing Hanbury Brown and Twiss phase

TL;DR

This paper explores the potential of using three-point intensity correlation measurements with existing technology to recover phase information of bright stars, enabling detailed stellar surface imaging and diameter measurements.

Contribution

It demonstrates the feasibility of three-point intensity interferometry with off-the-shelf detectors for bright stars, advancing observational capabilities beyond traditional methods.

Findings

Three-point correlations can recover phase information for bright stars.

Single photon counters with 100m2 collection areas are sufficient.

Potential for detailed stellar surface mapping and amateur diameter measurements.

Abstract

The interferometers of Hanbury Brown and collaborators in the 1950s and 60s, and their modern descendants now being developed (intensity interferometers) measure the spatial power spectrum of the source from intensity correlations at two points. The quantum optical theory of the Hanbury Brown and Twiss (HBT) effect shows that more is possible, in particular the phase information can be recovered by correlating intensities at three points (bispectrum). In this paper we argue that such 3 point measurements are possible for bright stars such as Sirius and Betelgeuse using off the shelf single photon counters with collecting areas of the order of 100m2. It seems possible to map individual features on the stellar surface. Simple diameter measurements would be possible with amateur class telescopes.