title: Large impacts around a solar-analog star in the era of terrestrial planet formation.
abstract: The final assembly of terrestrial planets occurs via massive collisions, which can launch copious clouds of dust that are warmed by the star and glow in the infrared. We report the real-time detection of a debris-producing impact in the terrestrial planet zone around a 35-million-year-old solar-analog star. We observed a substantial brightening of the debris disk at a wavelength of 3 to 5 micrometers, followed by a decay over a year, with quasi-periodic modulations of the disk flux. The behavior is consistent with the occurrence of a violent impact that produced vapor out of which a thick cloud of silicate spherules condensed that were then ground into dust by collisions. These results demonstrate how the time domain can become a new dimension for the study of terrestrial planet formation.
authors.affiliation: Lunar and Planetary Laboratory and Department of Planetary Sciences, University of Arizona, 1629 East University Boulevard, Tucson, AZ 85721, USA.
authors.forename: Huan Y A
authors.initials: HY
authors.lastname: Meng
authors.affiliation: Steward Observatory and Department of Astronomy, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA.
authors.forename: Kate Y L
authors.initials: KY
authors.lastname: Su
authors.affiliation: Lunar and Planetary Laboratory and Department of Planetary Sciences, University of Arizona, 1629 East University Boulevard, Tucson, AZ 85721, USA. Steward Observatory and Department of Astronomy, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA.
authors.forename: George H
authors.initials: GH
authors.lastname: Rieke
authors.affiliation: Division of Geological and Planetary Sciences, California Institute of Technology, MC 170-25, 1200 East California Boulevard, Pasadena, CA 91125, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Stevenson
authors.affiliation: NASA Exoplanet Science Institute, California Institute of Technology, MC 100-22, 770 South Wilson Avenue, Pasadena, CA 91125, USA. Missouri State University, 901 South National Avenue, Springfield, MO 65897, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Plavchan
authors.affiliation: Steward Observatory and Department of Astronomy, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA. Department of Physics, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330, Thailand. Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institute for Advanced Study, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, 277-8583, Japan.
authors.forename: Wiphu
authors.initials: W
authors.lastname: Rujopakarn
authors.affiliation: Space Department, Applied Physics Laboratory, Johns Hopkins University, 11100 Johns Hopkins Road, Laurel, MD 20723, USA.
authors.forename: Carey M
authors.initials: CM
authors.lastname: Lisse
authors.affiliation: National Astronomical Research Institute of Thailand (Public Organization), Ministry of Science and Technology, 191 Siriphanich Building, Huay Kaew Road, Muang District, Chiang Mai 50200, Thailand.
authors.forename: Saran
authors.initials: S
authors.lastname: Poshyachinda
authors.affiliation: Department of Physics and Astronomy, Campus Box 3255, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Reichart