Journal Article

Rapid formation of large dust grains in the luminous supernova 2010jl

Gall, Christa, Day-Jones, Avril C., Fox, Ori, Dwek, Eli, Leloudas, Giorgos, Hjorth, Jens, Maund, Justyn R., Watson, Darach, Malesani, Daniele

2014

Overview

The formation of dust in the dense circumstellar medium of the bright supernova 2010jl is at first rapid and produces very large grains, which resist destruction, whereas later the dust production rate increases, meaning its source is ejecta; this links early and late dust mass evolution in supernovae with dense circumstellar media. A supernova source for large dust grains Dust grains are found practically throughout the Universe and are crucial to galactic evolution, planet formation and much else. Yet it is still not clear where all this dust comes from and how it survives in the harsh environments of star-forming galaxies. Recent work suggested that dust might form in supernova remnants, although subsequent observations of the bright supernova SN 2010jl proved inconclusive. Christa Gall et al . now report spectrographic observations of SN 2010jl consistent with the rapid (40–240 days) formation of dust in its dense circumstellar medium. The wavelength-dependent extinction of this dust points to the presence of very large grains, greater than a micrometre in diameter, that resist destruction. At later times (around 500–900 days), near-infrared thermal emissions suggest an accelerated growth in dust mass. The origin of dust in galaxies is still a mystery 1 , 2 , 3 , 4 . The majority of the refractory elements are produced in supernova explosions, but it is unclear how and where dust grains condense and grow, and how they avoid destruction in the harsh environments of star-forming galaxies. The recent detection of 0.1 to 0.5 solar masses of dust in nearby supernova remnants 5 , 6 , 7 suggests in situ dust formation, while other observations reveal very little dust in supernovae in the first few years after explosion 1 , 8 , 9 , 10 . Observations of the spectral evolution of the bright SN 2010jl have been interpreted as pre-existing dust 11 , dust formation 12 , 13 or no dust at all 14 . Here we report the rapid (40 to 240 days) formation of dust in its dense circumstellar medium. The wavelength-dependent extinction of this dust reveals the presence of very large (exceeding one micrometre) grains, which resist destruction 15 . At later times (500 to 900 days), the near-infrared thermal emission shows an accelerated growth in dust mass, marking the transition of the dust source from the circumstellar medium to the ejecta. This provides the link between the early and late dust mass evolution in supernovae with dense circumstellar media.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 639/33/34/867 / Astronomical spectroscopy / Carbon / Confidence intervals / Cosmic dust / Dust / Explosions / Grain size / Humanities and Social Sciences / letter / Methods / multidisciplinary / Natural history / Observations / Properties / Science / Supernovae / Temperature