Eur. Phys. J. Plus (2017) 132: 347
https://doi.org/10.1140/epjp/i2017-11620-8

Regular Article

Physical characterization of NEA Large Super-Fast Rotator (436724) 2011 UW158

¹ Astronomical Observatory of the Autonomous Region of Aosta Valley (OAVdA), Aosta, Italy
² Hereford Arizona Observatory, Hereford (Cochise), USA
³ Blue Mountains Observatory, Leura (Sydney), Australia
⁴ Astronomical Station of Monteviasco, Monteviasco (Varese), Italy
⁵ Astronomical Observatory of San Marcello Pistoiese, San Marcello Pistoiese (Pistoia), Italy

^* e-mail: albino.carbognani@gmail.com

Received: 22 June 2017
Accepted: 3 July 2017
Published online: 11 August 2017

Abstract

Asteroids of size larger than 0.15km generally do not have periods smaller than 2.2 hours, a limit known as cohesionless spin barrier. This barrier can be explained by the cohesionless rubble-pile structure model. There are few exceptions to this “rule”, called LSFRs (Large Super-Fast Rotators), as (455213) 2001 OE84, (335433) 2005 UW163 and 2011 XA3. The near-Earth asteroid (436724) 2011 UW158 was followed by an international team of optical and radar observers in 2015 during the flyby with Earth. It was discovered that this NEA is a new candidate LSFR. With the collected lightcurves from optical observations we are able to obtain the amplitude-phase relationship, sideral rotation period ( h), a unique spin axis solution with ecliptic coordinates , and the asteroid 3D model. This model is in qualitative agreement with the results from radar observations.