3 years ago

A binary main-belt comet

A binary main-belt comet
Harold Weaver, Max Mutchler, David Jewitt, Jessica Agarwal, Stephen Larson

Asteroids are primitive Solar System bodies that evolve both collisionally and through disruptions arising from rapid rotation1. These processes can lead to the formation of binary asteroids2, 3, 4 and to the release of dust5, both directly and, in some cases, through uncovering frozen volatiles. In a subset of the asteroids called main-belt comets, the sublimation of excavated volatiles causes transient comet-like activity6, 7, 8. Torques exerted by sublimation measurably influence the spin rates of active comets9 and might lead to the splitting of bilobate comet nuclei10. The kilometre-sized main-belt asteroid 288P (300163) showed activity for several months around its perihelion 2011 (ref. 11), suspected to be sustained by the sublimation of water ice12 and supported by rapid rotation13, while at least one component rotates slowly with a period of 16 hours (ref. 14). The object 288P is part of a young family of at least 11 asteroids that formed from a precursor about 10 kilometres in diameter during a shattering collision 7.5 million years ago15. Here we report that 288P is a binary main-belt comet. It is different from the known asteroid binaries in its combination of wide separation, near-equal component size, high eccentricity and comet-like activity. The observations also provide strong support for sublimation as the driver of activity in 288P and show that sublimation torques may play an important part in binary orbit evolution.

Publisher URL: http://dx.doi.org/10.1038/nature23892

DOI: 10.1038/nature23892

You might also like
Never Miss Important Research

Researcher is an app designed by academics, for academics. Create a personalised feed in two minutes.
Choose from over 15,000 academics journals covering ten research areas then let Researcher deliver you papers tailored to your interests each day.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.