Extreme debris disk variability : exploring the diverse outcomes of large asteroid impacts during the era of terrestrial planet formation
| Autor: | Johan Olofsson, Renu Malhotra, Keivan G. Stassun, D. E. Reichart, Kate Y. L. Su, Ruobing Dong, Wiphu Rujopakarn, Joseph E. Rodriguez, Alan Jackson, George H. Rieke, Joshua Pepper, David James, Zoë M. Leinhardt, Grant M. Kennedy, Huan Meng, Michael Hammer, Andras Gaspar |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
dynamical evolution and stability [planets and satellites]
Planetesimal 010504 meteorology & atmospheric sciences FOS: Physical sciences circumstellar matter 01 natural sciences Astrobiology Planet 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics planetary systems [infrared] 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics 0105 earth and related environmental sciences Cosmic dust QB Earth and Planetary Astrophysics (astro-ph.EP) Physics individual (2MASS J08090250-4858172 2MASS J07354269-1450422) [stars] Debris disk Astronomy and Astrophysics Debris Space and Planetary Science Asteroid Physics::Space Physics Terrestrial planet Astrophysics::Earth and Planetary Astrophysics Protoplanet Astrophysics - Earth and Planetary Astrophysics |
| Zdroj: | Su, K Y L, Jackson, A P, Gáspár, A, Rieke, G H, Dong, R, Olofsson, J, Kennedy, G M, Leinhardt, Z M, Malhotra, R, Hammer, M, Meng, H Y A, Rujopakarn, W, Rodriguez, J E, Pepper, J, Reichart, D E, James, D & Stassun, K G 2019, ' Extreme Debris Disk Variability : Exploring the Diverse Outcomes of Large Asteroid Impacts during the Era of Terrestrial Planet Formation ', Astronomical Journal, vol. 157, no. 5 . https://doi.org/10.3847/1538-3881/ab1260 |
| ISSN: | 0004-6256 |
| DOI: | 10.3847/1538-3881/ab1260 |
| Popis: | The most dramatic phases of terrestrial planet formation are thought to be oligarchic and chaotic growth, on timescales of up to 100-200 Myr, when violent impacts occur between large planetesimals of sizes up to proto-planets. Such events are marked by the production of large amounts of debris as has been observed in some exceptionally bright and young debris disks (termed extreme debris disks). Here we report five years of Spitzer measurements of such systems around two young solar-type stars: ID8 and P1121. The short-term (weekly to monthly) and long-term (yearly) disk variability is consistent with the aftermaths of large impacts involving large asteroid-size bodies. We demonstrate that an impact-produced clump of optically thick dust, under the influence of the dynamical and viewing geometry effects, can produce short-term modulation in the disk light curves. The long-term disk flux variation is related to the collisional evolution within the impact-produced fragments once released into a circumstellar orbit. The time-variable behavior observed in the P1121 system is consistent with a hypervelocity impact prior to 2012 that produced vapor condensates as the dominant impact product. Two distinct short-term modulations in the ID8 system argue for two violent impacts at different times and locations. Its long-term variation is consistent with the collisional evolution of two different populations of impact-produced debris dominated by either vapor condensates or escaping boulders. The bright, variable emission from the dust produced in large impacts from extreme debris disks provides a unique opportunity to study violent events during the era of terrestrial planet formation. accepted for publication in AJ. typos and latex referencing fixed |
| Databáze: | OpenAIRE |
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