On the Rotation Period and Shape of the Hyperbolic Asteroid 1I/‘Oumuamua (2017 U1) from Its Lightcurve
Abstract
We observed the newly discovered hyperbolic minor planet 1I/‘Oumuamua (2017 U1) on 2017 October 30 with Lowell Observatory’s 4.3 m Discovery Channel Telescope. From these observations, we derived a partial lightcurve with a peak-to-trough amplitude of at least 1.2 mag. This lightcurve segment rules out rotation periods less than 3 hr and suggests that the period is at least 5 hr. On the assumption that the variability is due to a changing cross-section, the axial ratio is at least 3:1. We saw no evidence for a coma or tail in either individual images or in a stacked image having an equivalent exposure time of 9000 s.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 2017
- DOI:
- 10.3847/2041-8213/aa9d81
- arXiv:
- arXiv:1711.01402
- Bibcode:
- 2017ApJ...851L..31K
- Keywords:
-
- comets: general;
- ISM: individual objects: 1I&‘Oumuamua (2017 U1;
- methods: observational;
- minor planets;
- asteroids: individual: 1I&‘Oumuamua (2017 U1;
- techniques: photometric;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- Updated in response to referee's comments. Accepted by ApJL