Caltech Logo

Dix Planetary Science Seminar

Tuesday, April 9, 2019
4:00pm to 5:00pm
Add to Cal
South Mudd 365
The trajectory of interstellar visitor 'Oumuamua
Davide Farnocchia, Navigation Engineer, JPL,

The object now known as 1I/'Oumuamua was discovered on 2017 October 19 by the Pan-STARRS1 survey. Within a few days of discovery, additional observations collected with ESA's Optical Ground Station telescope and other observatories, together with pre-discovery data from Pan-STARRS1, showed that the orbit of 'Oumuamua was hyperbolic with an eccentricity of 1.2, identifying the object as originating from outside the Solar System and approaching from the direction of the constellation Lyra, with an asymptotic inbound velocity of about 26 km/s. A variety of physical observations collected during the visit of 'Oumuamua to the Solar System show that the object has an unusually elongated shape and a tumbling rotation state, while its surface physical properties resemble those of cometary nuclei, even though 'Oumuamua showed no evidence of cometary activity. With the goal of further constraining the trajectory of 'Oumuamua, we collected high-quality astrometry with the Canada-France-Hawaii Telescope, the ESO Very Large Telescope, and the Hubble Space Telescope. The resulting dataset provides dense coverage from discovery to 2018 January 2, when 'Oumuamua became fainter than V = 27 at a heliocentric distance of 2.9 au. We present the results of our trajectory analysis and discuss the implications on the nature and origin of this interstellar visitor.

For more information, please contact Nicole Wallack by email at [email protected].