3841 Dicicco

Lore & Background

3841 Dicicco is a member of the Flora family, one of the largest groups of stony asteroids in the inner main-belt. It orbits the Sun at a distance of 1.9–2.6 AU once every 3 years and 5 months (1,252 days), with an eccentricity of 0.16 and an inclination of 5° with respect to the ecliptic. It was first identified as 1973 YM2 at Crimea–Nauchnij in 1973, extending the body's observation arc by 10 years prior to its official discovery observation at Anderson Mesa. Physically, Dicicco is a stony S-type asteroid in the SMASS classification. In December 2014, two rotational lightcurves were obtained from photometric observations by an international collaboration of American and European astronomers, giving a rotation period of 3.5949 and 3.5950 hours with a brightness amplitude of 0.18 and 0.19 magnitude, respectively. According to the NEOWISE survey, Dicicco measures between 4.74 and 6.45 kilometers in diameter with an albedo between 0.294 and 0.38; the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 and derives a diameter of 5.10 kilometers. During the photometric observations in December 2014, it was revealed that Dicicco is a synchronous binary asteroid. Its minor-planet moon measures at least 1.67 kilometers in diameter based on a diameter-ratio of larger than 0.28. The moon's orbit has an estimated semi-major axis of 12 kilometers, and a derived period of 21.63 and 21.641 hours, respectively. The asteroid was named after American amateur astronomer and astrophotographer Dennis di Cicco, with the naming citation published by the Minor Planet Center on 10 April 1990.

Reader's Guide

3841 Dicicco holds significance as a synchronous binary asteroid, a relatively rare configuration where the primary and its moon are tidally locked. Its discovery as a binary system in 2014, through photometric observations by an international collaboration, adds to the understanding of asteroid satellite formation and dynamics within the Flora family. The asteroid's stony S-type composition and membership in the Flora family, one of the largest asteroid groups in the inner main-belt, provide context for studying the collisional history and evolution of small bodies. The naming after Dennis di Cicco, an American amateur astronomer and astrophotographer, honors contributions to the field. The range of diameter estimates from NEOWISE (4.74–6.45 km) and the Collaborative Asteroid Lightcurve Link (5.10 km) reflects typical uncertainties in asteroid physical characterization. The moon's estimated orbit (semi-major axis 12 km, period ~21.6 hours) and minimum diameter (1.67 km) offer constraints for binary asteroid models. The asteroid's observation arc extends back to 1973, aiding orbital refinement. Its discovery at Lowell's Anderson Mesa Station by Brian Skiff continues the tradition of asteroid surveys from that site.

Did You Know?

• 3841 Dicicco is a synchronous binary asteroid with a moon at least 1.67 km in diameter.
• Its minor-planet moon was discovered in 2014 during photometric observations.