Lunar occultations with Aqueye+ and Iqueye

Abstract

We report the first-time use of the Aqueye+ and Iqueye instruments to record lunar occultation events. High-time resolution recordings in different filters have been acquired for several occultations taken from January 2016 through January 2018 with Aqueye+ at the Copernicus telescope and Iqueye at the Galileo telescope in Asiago, Italy. Light curves with different time bins were calculated in post-processing and analyzed using a least-square model-dependent method. A total of nine occultation light curves were recorded, including one star for which we could measure for the first time the size of the chromosphere ($\mu$ Psc) and one binary star for which discrepant previous determinations existed in the literature (SAO 92922). A disappearance of Alf Tau shows an angular diameter in good agreement with literature values. The other stars were found to be unresolved, at the milliarcsecond level. We discuss the unique properties of Aqueye+ and Iqueye for this kind of observations, namely the simultaneous measurement in up to four different filters thanks to pupil splitting, and the unprecedented time resolution well exceeding the microsecond level. This latter makes Aqueye+ and Iqueye suitable to observe not just occultations by the Moon, but also much faster events such as e.g. occultations by artificial screens in low orbits. We provide an outlook of future possible observations in this context.

arXiv comment10 pages, 5 figures, accepted for publication in The Astronomical Journal

References in corpus (14)

• Gaia Data Release 2. Summary of the contents and survey properties
• The SIMBAD astronomical database
• The EMCCD-Based Speckle Interferometer of the BTA 6-m Telescope: Description and First Results
• Modelling Chromospheric Line Profiles in NGC2808: Evidence of Mass Loss from RGB Stars
• Aldebaran's angular diameter: how well do we know it?
• Direct measurement of stellar angular diameters by the VERITAS Cherenkov Telescopes
• Intensity Interferometry with Aqueye+ and Iqueye in Asiago
• Modelling chromospheric line profiles as diagnostics of velocity fields in ω Centauri red giant stars
• Aqueye+: a new ultrafast single photon counter for optical high time resolution astrophysics
• Evidence of asymmetries in the Aldebaran photosphere from multi-wavelength lunar occultations
• Final Binary Stars Results From The VLT Lunar Occultations Program
• The future of stellar occultations by distant solar system bodies: perspectives from the Gaia astrometry and the deep sky surveys
• High Angular Resolution Stellar Imaging with Occultations from the Cassini Spacecraft I: Observational Technique
• High Angular Resolution Stellar Imaging with Occultations from the Cassini Spacecraft II: Kronocyclic Tomography