AI Insight
This study demonstrates a novel method for measuring the angular sizes of stars by using artificial satellites and the Moon to create brief eclipses observable with high-speed photon detectors. The technique overcomes traditional optical diffraction limits by analyzing the time-domain information as satellites pass in front of stars, achieving resolutions better than 2 milliarcseconds. The researchers developed a Bayesian statistical framework to analyze simulated observations and estimate that approximately 10,000 stars could be measured annually, with 10-100 stars achieving diameter measurements accurate to better than 0.5 milliarcseconds.
Why it matters
This technique could revolutionize stellar angular size measurements, providing precise data for thousands of stars that are currently difficult to resolve with conventional telescopes. Such measurements are crucial for understanding stellar physics, testing stellar evolution models, and calibrating distance measurements in astronomy.
Understand the Science
⚠️ Preprint – Noch nicht peer-reviewed
Dieser Artikel wurde noch nicht von unabhängigen Experten begutachtet. Die Ergebnisse sind vorläufig und sollten mit Vorsicht interpretiert werden.
Abstract: Direct measurements of the angular sizes of stars (other than our Sun) are inherently limited by telescopes’ optical diffraction limit. The spatial diffraction limit can be overcome by using time-domain information when stars are `eclipsed’ by anything moving in the foreground: artificial satellites or the Moon (known as `lunar occultation imaging’). Here we analyse the angular resolution achievable by high-speed photon counting devices, when stars are eclipsed for several microseconds by one of the thousands of satellites now in low or mid-Earth orbit. We also build a full Bayesian statistical treatment for analysing simulated observations.
We show that eclipses by the moon and satellites deliver $<2$ milliarcsecond resolution for $sim$$10^4$ stars every year, with the diameters of $sim$$10^1 – 10^2$ stars constrained to better than $0.5$ milliarcseconds. The application of satellites requires an ultra-fast, photon-resolving detector, capable of continuous readout with inter-frame delay controlled within $lesssim 1$ $mu$s. Such a fast rate can easily be handled by the SPINA instrument, which has demonstrated $8$ ns inter-frame delay, and potentially by the Cherenkov Telescope Array.
Source: Eclipses by Artificial Satellites to Measure the Angular Sizes of Stars