PanSTARRS Archives

Left panels: C/2024 G3 ATLAS observed by the SOHO spacecraft on 2025 Jan 13.446-13.487 UT in four LASCO C3 passbands (Sun at bottom, images 1.2 107 km wide). The horizontal trail is visible in the orange passband only (540-640 nm). Right panel: SOHO image taken on 2025 Jan 14.454 UT in the clear passband. The curved continuous lines are the predicted atomic neutral tails, from left to right: LiI tail (syndyne of β = 440); NaI tail (syndyne of β = 71); KI tail (syndyne of β = 53); FeI tail (syndyne of β = 6). Dotted line: Comet orbit fitting the trail. -- astro-ph.EP

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Status Report

Alkali Phenoxides In Comets

by Keith CowingJune 7, 2025June 7, 2025

Potassium was first detected in spectra of the sungrazer comet Ikeya-Seki at the heliocentric distance rh = 0.15 au and, 48 years later, in comets PanSTARRS and ISON at rh […]

ZTF zr-band intensity image of K2 (upper row) and its enhanced version divided by azimuthal median (lower row) taken at or near the time of VLT polarimetric observations: on UT 2022 May 11.4 for Epoch ♯1, UT 2022 June 26.4 for Epoch ♯2, and UT 2022 July 19.3 for Epoch ♯3. All images were normalized on the same brightness scale and aligned with the North on top and the East on the left. Anti-sunward (⃗r⊙) and negative velocity (−⃗v) vectors at each epoch are given. Green circles in the center encircle the outer boundary of the polarimetric aperture. -- astro-ph.EP

Astrochemistry, Astrogeology, Comets and Asteroids, Status Report

The Pre-perihelion Evolution of the Activity of Comet C/2017 K2 (PANSTARRS) During the Water Ice-line Crossover

by Keith CowingAugust 11, 2024August 10, 2024

Comets, relics from the early solar system, consist of dust and ice. The ice sublimates as comets approach the Sun, ejecting dust from their nuclei seen as activity. Different volatiles […]

Water production rate in comet C/2021 A1 (Leonard) as a function of time from perihelion. The points give the water production rate in s-1 from single images. The error bars give the 1-s formal random fitting errors for each value. There is a ~30% uncertainty from the model parameters and calibration. -- astro-ph.EP

Astrochemistry, Comets and Asteroids, Status Report

Water Production Rates from SOHO/SWAN Observations of Comets C/2020 S3 (Erasmus), C/2021 A1 (Leonard) and C/2021 O3 (PanSTARRS)

by Keith CowingApril 11, 2023April 11, 2023

In 2021 and 2022 the hydrogen comae of three long period comets, C/2020 S3 (Erasmus), C/2021 A1 (Leonard) and C/2021 O3 (PanSTARRS) were observed with the Solar Wind ANisotropies (SWAN) […]