46P/Wirtanen Archives

Images of comet 7P/Pons–Winnecke taken during a period of quiescence (left, taken at 2021 July 28 10:25:23 UTC) and the 2021 July 10 outburst (right, taken at 2021 July 10 02:29:58 UTC). The outburst ejecta is apparent as distortions in the observed surface brightness as compared to the ambient coma image. The bottom row shows the logarithmically scaled data with contours spaced every 0.5 mag/arcsec2 . A color bar provides the surface brightness scale. Images are oriented with north up, and east to the left. -⊙ represents the anti-solar direction and V is the heliocentric velocity direction, and a linear scale bar is shown. The blue arrows highlight two linear features as a result of the ejecta distribution that are meeting at a near-right angle in front of the nucleus. -- astro-ph.EP

A Look At Eight Outbursts Of Comet 7P/Pons-Winnecke

by Keith CowingJune 26, 2026June 26, 2026

Cometary outbursts may be used as a means to infer the physical processes occurring on cometary nuclei. To that end, we studied eight outbursts of comet 7P/Pons-Winnecke identified between 2021 […]

This 120 second image of the comet was taken Dec. 2 by an iTelescope 50 mm refractor located at an observatory near Mayhill, New Mexico. The streak below the comet was produced by a rocket body (upper stage) passing through the telescope's field of view during the exposure. Credit: NASA

Astrochemistry, Biochemistry & Organic Chemistry, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Status Report

Evidence for Surprising Heavy Nitrogen Isotopic Enrichment in Comet 46P/Wirtanen’s Hydrogen Cyanide

by Keith CowingSeptember 10, 2024September 10, 2024

46P/Wirtanen is a Jupiter-family comet, probably originating from the Solar System’s Kuiper belt, that now resides on a 5.4 year elliptical orbit. During its 2018 apparition, comet 46P passed unusually […]

Monte Carlo icy grain model for grain sizes randomly sampled from the size frequency distribution governed by the α=-5.989 power law. All particles are subject to gravitational force from the comet nucleus, pressure from the expanding coma gas (assumed to be H2O), and solar radiation pressure at 1 au. The plot is 15000 km by 15000 km and shown in a logarithmic scale to match the top row of images shown in Figure 1. The model results have been rotated to match the Earth viewing geometry at the time of observation, a phase angle of 18 degrees and a orbital difference angle of -16 degrees. The general morphology of the model is in agreement with observations shown in in Figure 1. -- astro-ph.EP

Astrochemistry, Astrogeology, Comets and Asteroids, Status Report

Ice, Ice, Maybe? Investigating 46P/Wirtanen’s Inner Coma For Icy Grains

by Keith CowingMay 21, 2023May 21, 2023

The release of volatiles from comets is usually from direct sublimation of ices on the nucleus, but for very or hyper-active comets other sources have to be considered to account […]