Parker Solar Probe Observations of a Dust Trail in the Orbit of (3200) Phaethon

TL;DR

This paper reports the detection and analysis of a dust trail associated with asteroid (3200) Phaethon using Parker Solar Probe observations, providing insights into the Geminid meteor stream's composition and origin.

Contribution

First observation of Phaethon's dust trail by Parker Solar Probe, estimating its mass and linking it to the Geminid stream's natural clustering near perihelion.

Findings

Dust trail observed with surface brightness of 25.0 mag arcsec$^{-2}$.

Estimated trail mass of approximately 0.4-1.3×10^{12} kg.

Trail likely represents a natural clustering of Geminid stream material.

Abstract

We present the identification and preliminary analysis of a dust trail following the orbit of (3200) Phaethon as seen in white light images recorded by the Wide-field Imager for Parker Solar Probe (WISPR) instrument on the NASA Parker Solar Probe (PSP) mission. During PSP's first solar encounter in November 2018, a dust trail following Phaethon's orbit was visible for several days and crossing two fields of view. Preliminary analyses indicate this trail to have a visual magnitude of 15.8 $\pm$0.3 per pixel and a surface brightness of 25.0 mag arcsec$^{-2}$ as seen by PSP/WISPR from a distance of $\sim$0.2 au from the trail. We estimate the total mass of the stream to be $\sim(0.4-1.3){\times}10^{12}$ kg, which is consistent with, though slightly underestimates, the assumed mass of the Geminid stream but is far larger than the current dust production of Phaethon could support. Our results imply that we are observing a natural clustering of at least some portion of the Geminid meteor stream through its perihelion, as opposed to dust produced more recently from perihelion activity of Phaethon.