Physical Characterization of Active Asteroid (6478) Gault

Juan A. Sanchez, Vishnu Reddy, Audrey Thirouin, Edward L. Wright, Tyler R. Linder, Theodore Kareta, Benjamin Sharkey

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

Main belt asteroid (6478) Gault has been dynamically linked with two overlapping asteroid families: Phocaea, dominated by S-type asteroids, and Tamara, dominated by low-albedo C-types. This object has recently become an interesting case for study after images obtained in late 2018 revealed that it was active and displaying a comet-like tail. Previous authors have proposed that the most likely scenarios to explain the observed activity on Gault were rotational excitation or merger of near-contact binaries. Here we use new photometric and spectroscopic data of Gault to determine its physical and compositional properties. Lightcurves derived from the photometric data showed little variation over three nights of observations, which prevented us from determining the rotation period of the asteroid. Using WISE observations of Gault and the near-Earth Asteroid Thermal Model (NEATM) we determined that this asteroid has a diameter <6 km. Near-infrared spectroscopic data obtained with the Infrared Telescope Facility showed a spectrum similar to that of S-complex asteroids, and a surface composition consistent with H chondrite meteorites. These results favor a compositional affinity between Gault and asteroid (25) Phocaea, and rules out a compositional link with the Tamara family. From the spectroscopic data we found no evidence of fresh material that could have been exposed during the outburst episodes.

Original languageEnglish (US)
Article numberL6
JournalAstrophysical Journal Letters
Volume881
Issue number1
DOIs
StatePublished - Aug 10 2019

Keywords

  • minor planets, asteroids: general
  • techniques: spectroscopic

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint

Dive into the research topics of 'Physical Characterization of Active Asteroid (6478) Gault'. Together they form a unique fingerprint.

Cite this