Planetary Collisions outside the Solar System: Time Domain Characterization of Extreme Debris Disks

Abstract

Luminous debris disks of warm dust in the terrestrial planet zones around solar-like stars are recently found to vary, indicative of ongoing large-scale collisions of rocky objects. We use Spitzer 3.6 and 4.5 μm time-series observations in 2012 and 2013 (extended to 2014 in one case) to monitor 5 more debris disks with unusually high fractional luminosities ("extreme debris disk"), including P1121 in the open cluster M47 (80 Myr), HD 15407A in the AB Dor moving group (80 Myr), HD 23514 in the Pleiades (120 Myr), HD 145263 in the Upper Sco Association (10 Myr), and the field star BD+20 307 (>1 Gyr). Together with the published results for ID8 in NGC 2547 (35 Myr), this makes the first systematic time-domain investigation of planetary impacts outside the solar system. Significant variations with timescales shorter than a year are detected in five out of the six extreme debris disks we have monitored. However, different systems show diverse sets of characteristics in the time domain, including long-term decay or growth, disk temperature variations, and possible periodicity.

50 pages, 14 figures, 9 tables; Accepted for publication in the Astrophysical Journal

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Cited by in corpus (16)

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• The transiting dust clumps in the evolved disk of the Sun-like UXor RZ Psc
• A new sample of warm extreme debris disks from the ALLWISE catalog
• Extinction and the Dimming of KIC 8462852
• Mid-infrared Studies of HD 113766 and HD 172555: Assessing Variability in the Terrestrial Zone of Young Exoplanetary Systems
• Extreme Variability of the V488 Persei Debris Disk
• Studying the Evolution of Warm Dust Encircling BD +20 307 Using SOFIA
• Collisions of Terrestrial Worlds: The Occurrence of Extreme Mid-Infrared Excesses around Low-Mass Field Stars
• Variable warm dust around the Herbig Ae star HD~169142: Birth of a ring?
• Sudden extreme obscuration of a Sun-like main-sequence star: evolution of the circumstellar dust around ASASSN-21qj
• Mid-infrared time-domain study of recent dust production events in the extreme debris disc of TYC 4209-1322-1
• Catastrophic events in protoplanetary disks and their observational manifestations
• Abundant sub-micron grains revealed in newly discovered extreme debris discs
• Isolating the extreme debris disc signature -- explorations of eccentric extreme debris discs formed by giant impacts
• On The Unusual Variability of 2MASS J06195260-2903592: A Long-Lived Disk around a Young Ultracool Dwarf