Meteor shower modeling: Past and future Draconid outbursts

Abstract

This work presents numerical simulations of meteoroid streams released by comet 21P/Giacobini-Zinner over the period 1850-2030. The initial methodology, based on Vaubaillon et al. (2005), has been updated and modified to account for the evolution of the comet's dust production along its orbit. The peak time, intensity, and duration of the shower were assessed using simulated activity profiles that are calibrated to match observations of historic Draconid outbursts. The characteristics of all the main apparitions of the shower are reproduced, with a peak time accuracy of half an hour and an intensity estimate correct to within a factor of 2 (visual showers) or 3 (radio outbursts). Our model also revealed the existence of a previously unreported strong radio outburst on October 9 1999, that has since been confirmed by archival radar measurements. The first results of the model, presented in Egal et al. (2018), provided one of the best predictions of the recent 2018 outburst. Three future radio outbursts are predicted in the next decade, in 2019, 2025 and 2029. The strongest activity is expected in 2025 when the Earth encounters the young 2012 trail. Because of the dynamical uncertainties associated with comet 21P's orbital evolution between the 1959 and 1965 apparitions, observations of the 2019 radio outburst would be particularly helpful to improve the confidence of subsequent forecasts.

Realistic gravitational focusing of meteoroid streams

“…Second, the gravitational influence of planets in a solar system is limited to their Hill sphere. In the case of the Earth, the Hill sphere is generally smaller than a meteoroid stream (although there can be exceptions; for instance Egal et al 2019, predict Draconid filaments narrower than 0.01 au). The Earth's Hill radius corresponds to a "smoothing speed" of 48 m s −1 .…”

Modeling the past and future activity of the Halleyid meteor showers

“…Meteoroid stream simulations performed in this work follow the methodology described in Egal et al (2019). Using an A120, page 7 of 28 A&A 642, A120 (2020) ephemeris of the comet's past orbital behavior as its basis, millions of test particles are ejected from the comet nucleus and numerically integrated forward in time.…”

“…The purpose of the present work is to apply the new numerical model of meteoroid stream evolution developed in Egal et al (2019) to the Halleyids. In particular, the long-term evolution of these streams can now be constrained by the 35 yr of observations reported in Egal et al (2020).…”

“…In particular, the long-term evolution of these streams can now be constrained by the 35 yr of observations reported in Egal et al (2020). Through extensive numerical simulations and the application of an adapted weighting solution to the ejected particles (see, e.g., Egal et al 2019), we constrained the model parameters using the η-Aquariid and Orionid intensity profiles and interannual variability since 1985. The simulation parameters are calibrated on the tens of annual apparitions of each shower to increase the model's robustness.…”

Estimating trajectories of meteors: an observational Monte Carlo approach – II. Results

“…In Paper 1 we examined the most commonly used meteor trajectory estimation methods in detail, including: the geometrical intersecting planes (Ceplecha 1987) and lines of sight (Borovička 1990) approaches, and the multi-parameter fit (MPF) method by Gural (2012). As pointed out by Egal et al (2017), the true measurement accuracy of these methods for various meteor observation systems and showers is unknown, and the most advanced of them, the MPF method with the exponential deceleration velocity model, is numerically problematic to fit to observations.…”