Physical characterization of two kilometer-sized binary main-belt asteroids: (1967) Menzel and (20325) Julianoey

Résumé fourni par la source

Abstract Light curve observations of two main-belt asteroids, (1967) Menzel and (20325) Julianoey, were carried out at OASI and BMO between 2016 and 2021. Menzel was observed from August to November 2018, while Julianoey was observed from April 2016 to October 2021. These observations revealed that both objects may be binary systems, with two additive periods and fast rotation of the primary component. Julianoey’s data show pronounced V-shaped minima due to eclipse events in the secondary light curve, while Menzel’s data reveal a well-defined secondary rotational light curve. For Julianoey, we derived an orbital period of about 23.53 h, while for Menzel we obtained a secondary period of approximately 63 h, associated with the rotational period of a suspected satellite. By applying the light curve inversion method, we derived the pole directions in ecliptic coordinates, although not uniquely constrained, along with an irregular oblate shape for the primary components. Multicolor photometry with SDSS g, r, i, z filters enabled taxonomic classification. Asteroid Menzel was identified as a Q-type, while asteroid Julianoey was classified as an S-type. Furthermore, phase curves and absolute magnitudes were obtained in the V-band, allowing the derivation of their effective diameters. Julianoey’s binary nature was previously reported, and our study expands its characterization. Menzel remains a candidate binary system, with confirmation dependent on the future detection of mutual events. Finally, our findings on Julianoey and Menzel indicate that both binary systems may have formed through rotational fission.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.