Six Outbursts of Comet 46P/Wirtanen

Abstract

Cometary activity is a manifestation of sublimation-driven processes at the surface of nuclei. However, cometary outbursts may arise from other processes that are not necessarily driven by volatiles. In order to fully understand nuclear surfaces and their evolution, we must identify the causes of cometary outbursts. In that context, we present a study of mini-outbursts of comet 46P/Wirtanen. Six events are found in our long-term lightcurve of the comet around its perihelion passage in 2018. The apparent strengths range from $-0.2$ to $-1.6$ mag in a 5" radius aperture, and correspond to dust masses between $\sim 10^4$ to $10^6$ kg, but with large uncertainties due to the unknown grain size distributions. However, the nominal mass estimates are the same order of magnitude as the mini-outbursts at comet 9P/Tempel 1 and 67P/Churyumov-Gerasimenko, events which were notably lacking at comet 103P/Hartley 2. We compare the frequency of outbursts at the four comets, and suggest that the surface of 46P has large-scale ($\sim$10-100 m) roughness that is intermediate to that of 67P and 103P, if not similar to the latter. The strength of the outbursts appear to be correlated with time since the last event, but a physical interpretation with respect to solar insolation is lacking. We also examine Hubble Space Telescope images taken about 2 days following a near-perihelion outburst. No evidence for macroscopic ejecta was found in the image, with a limiting radius of about 2-m.

arXiv commentAccepted for publication in The Planetary Science Journal. 33 pages, 11 figures, 3 tables

References in corpus (31)

• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• The Zwicky Transient Facility: System Overview, Performance, and First Results
• Cosmic-Ray Rejection by Laplacian Edge Detection
• The Zwicky Transient Facility: Data Processing, Products, and Archive
• ATLAS: A High-Cadence All-Sky Survey System
• The Zwicky Transient Facility: Science Objectives
• astroquery: An Astronomical Web-Querying Package in Python
• Nominal values for selected solar and planetary quantities: IAU 2015 Resolution B3
• The Absolute Magnitude of the Sun in Several Filters
• SkyMapper Southern Survey: First Data Release (DR1)
• The Zwicky Transient Facility: Surveys and Scheduler
• The ATLAS All-Sky Stellar Reference Catalog
• Summer fireworks on comet 67P
• The size distribution of Jupiter Family comet nuclei
• Comet 67P outbursts and quiescent coma at 1.3 AU from the Sun: dust properties from Rosetta/VIRTIS-H observations
• Evidence of sub-surface energy storage in comet 67P from the outburst of 2016 July 3
• The Discovery of Cometary Activity in Near-Earth Asteroid (3552) Don Quixote
• Water Production by Comet 103P/Hartley 2 Observed with the SWAN Instrument on the SOHO Spacecraft
• Constraints on cometary surface evolution derived from a statistical analysis of 67P's topography
• The Formation of Striae within Cometary Dust Tails by a Sublimation-Driven YORP-like Effect
• Outburst and Splitting of Interstellar Comet 2I/Borisov
• Mt. Wendelstein Imaging of the Post-Perihelion Dust Coma of 67P/Churyumov-Gerasimenko in 2015/2016
• Fragmentation Kinematics in Comet 332P/Ikeya-Murakami
• 2014-2015 Multiple Outbursts of 15P/Finlay
• 2006 Fragmentation of Comet 73P/Schwassmann-Wachmann 3B Observed with Subaru/Suprime-Cam
• Local manifestations of cometary activity
• First Results from TESS Observations of Comet 46P/Wirtanen
• Implications of the Small Spin Changes Measured for Large Jupiter-Family Comet Nuclei
• Monitoring polarization in comet 46P/Wirtanen
• Modeling of the outburst on July 29th, 2015 observed with OSIRIS cameras in the southern hemisphere of comet 67P/Churyumov-Gerasimenko
• Long-Term Monitoring of Comet 103P/Hartley 2

Cited by in corpus (4)

• Activity and composition of the hyperactive comet 46P/Wirtanen during its close approach in 2018
• Searching for Outbursts in the Ground-Based Photometry of 67P/Churyumov-Gerasimenko
• First Detection of Molecular Activity in the Largest Known Oort Cloud Comet: ALMA Imaging of C/2014 UN271 (Bernardinelli-Bernstein) at 16.6 au from the Sun
• Enlargement of depressions on comet 81P/Wild 2: Constraint based on 30-year cometary activity in the inner Solar System