Searching for main-belt comets using the Canada–France–Hawaii Telescope Legacy Survey

Gilbert, A. M.; Wiegert, Paul

doi:10.1016/j.icarus.2009.01.011

Cited by 27 publications

(30 citation statements)

References 19 publications

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“…For example, we expect the spatial distribution of collisionally produced or triggered objects to be correlated with the regions of the asteroid belt in which the collision probability per unit time is highest. Unfortunately, the published surveys for active asteroids so far either are biased (Hsieh 2009) or, if unbiased, detected no objects and so provide insufficient information (Gilbert & Wiegert 2009, 2010Sonnett et al 2011). All but one of the known active asteroids were discovered serendipitously by a variety of surveys and methods, most too poorly quantified in terms of reported areal coverage and limiting magnitude to be used to interpret the spatial distribution.…”

Section: Discussionmentioning

confidence: 99%

The Active Asteroids

Jewitt

2012

The Astronomical Journal

287

244

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Some asteroids eject dust, unexpectedly producing transient, comet-like comae and tails. First ascribed to the sublimation of near-surface water ice, mass-losing asteroids (also called "main-belt comets") can in fact be driven by a surprising diversity of mechanisms. In this paper, we consider 11 dynamical asteroids losing mass, in nine of which the ejected material is spatially resolved. We address mechanisms for producing mass loss including rotational instability, impact ejection, electrostatic repulsion, radiation pressure sweeping, dehydration stresses, and thermal fracture, in addition to the sublimation of ice. In two objects (133P and 238P) the repetitive nature of the observed activity leaves ice sublimation as the only reasonable explanation, while in a third ((596) Scheila), a recent impact is the cause. Another impact may account for activity in P/2010 A2, but this tiny object can also be explained as having shed mass after reaching rotational instability. Mass loss from (3200) Phaethon is probably due to cracking or dehydration at extreme (∼1000 K) perihelion temperatures, perhaps aided by radiation pressure sweeping. For the other bodies, the mass-loss mechanisms remain unidentified, pending the acquisition of more and better data. While the active asteroid sample size remains small, the evidence for an astonishing diversity of mass-loss processes in these bodies is clear.

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Section: Discussionmentioning

confidence: 99%

The Active Asteroids

Jewitt

2012

The Astronomical Journal

287

244

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“…The images were searched for moving objects using a pipeline previously used successfully to search for main-belt comets and asteroids (Wiegert et al 2007;Gilbert & Wiegert 2009, 2010August & Wiegert 2013). The pipeline extracts image sources using the Source Extractor package (Bertin & Arnouts 1996), and examines the source list and reports on pairs or triplets of sources consistent with a solar system body moving within some user-defined parameter range.…”

Section: Archival Data Searchmentioning

confidence: 99%

Constraints on Comet 332p/Ikeya-Murakami

Hui

Wiegert

2016

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Encke-type comet 332P/Ikeya-Murakami is experiencing cascading fragmentation events during its 2016 apparition. It is likely the first splitting Encke-type comet ever being observed. A nongravitational solution to the astrometry reveals a statistical detection of the radial and transverse nongravitational parameters, A 1 = (1.54 ± 0.39) × 10 −8 AU day −2 , and A 2 = (7.19 ± 1.92) × 10 −9 AU day −2 , respectively, which implies a nucleus erosion rate of (9.1 ± 1.7) per orbital revolution. The mass-loss rate likely has to be supported by a much larger fraction of an active surface area than known cases of short-period comets; it may be relevant to the ongoing fragmentation. We failed to detect any serendipitous pre-discovery observations of the comet in archival data from major sky surveys, whereby we infer that 332P used to be largely inactive, and is perhaps among the few short-period comets which have been reactivated from weakly active or dormant states. We therefore constrain an upper limit to the nucleus size as 2.0±0.2 km in radius. A search for small bodies in similar orbits to that of 332P reveals comet P/2010 B2 (WISE) as the best candidate. From an empirical generalised Jupiter-family (Encke-type included) comet population model, we estimate the likelihood of chance alignment of the 332P-P/2010 B2 pair to be 1 in 33, a small number indicative of a genetic linkage between the two comets on a statistical basis. The pair possibly originated from a common progenitor which underwent a disintegration event well before the twentieth century.

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“…The observations were taken at opposition and had a particular cadence (three images taken 45 min apart the first night, with an additional image taken either 24 h before or after, weather permitting) that allowed for a reasonable determination of orbital parameters. For more details on the observations and data reduction methods, see Gilbert and Wiegert (2009).…”

Section: Observations and Analysismentioning

confidence: 99%

“…In this paper, the results of a search for MBCs using the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) are updated (Gilbert and Wiegert, 2009). In the initial study, approximately half of the Very Wide segment of data was visually inspected for cometary activity (see Section 3.2 of Gilbert and Wiegert (2009) for more details).…”

Section: Introductionmentioning

confidence: 99%