20–27 Mar 2026
Wild View Resorts
Africa/Gaborone timezone

Stellar Occultation Measurements of Asteroids Using the 1.88-m Kottamia Telescope for Diameter and Shape Refinement

25 Mar 2026, 11:15
15m
Wild View Resorts

Wild View Resorts

Plot 80 President Avenue, Kasane, Botswana
In-person - Talk 5 Transients, Compact Objects Science & Engineering

Speaker

Ahmed Moursi (National Research Institute of Astronomy and Geophysics(NRIAG))

Description

Stellar occultations, in which an asteroid transits across the line of sight to a background star, provide one of the most accurate ground-based methods for determining asteroid diameters, shapes, and possible companions. This study reports on a series of predicted asteroid occultation events monitored using the 1.88-m Kottamia Telescope in Egypt. High-cadence CCD imaging and photometric time-series acquisition were employed to capture the flux drop associated with each transit event. Standard calibration and differential photometry techniques were applied to extract precise light curves. The disappearance and reappearance times of the occulted star were measured with sub-second timing accuracy using GPS-synchronized recording. These chord measurements were compared with occultation prediction models and existing shape profiles from Gaia DR3 and previous occultation campaigns. The results yielded updated estimates of asteroid effective diameters, limb profiles, and, in one case, evidence of a possible non-spherical (elongated) body shape. The study demonstrates the capability of the 1.88-m Kottamia Telescope to contribute high-quality transit-based asteroid characterization and supports coordinated planetary defense and Solar System small-body research efforts.

Stream Science or Engineering

Primary author

Ahmed Moursi (National Research Institute of Astronomy and Geophysics(NRIAG))

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