Radar Observations of the 2011 October Draconid Outburst

TL;DR

This paper reports radar observations of the 2011 October Draconid meteor outburst, detailing radiant position, velocity, and mass distribution, and compares findings with model predictions to improve understanding of meteoroid behavior.

Contribution

It provides the first detailed radar-based analysis of the 2011 Draconid outburst, including radiant, velocity, and mass index measurements, and discusses discrepancies with models.

Findings

Radiant position matches model predictions within 1 degree.

Measured geocentric velocity was 10-15% lower than models.

Mass index during outburst was approximately 1.75.

Abstract

A strong outburst of the October Draconid meteor shower was predicted for October 8, 2011. Here we present the observations obtained by the Canadian Meteor Orbit Radar (CMOR) during the 2011 outburst. CMOR recorded 61 multi-station Draconid echoes and 179 single-station overdense Draconid echoes (covering the magnitude range of +3 <= MV <= +7) between 16-20h UT on October 8, 2011. The mean radiant for the outburst was determined to be a_g = 261.9o +/- 0.3o, d_g = +55.3o +/- 0.3o (J2000) from observations of the underdense multi-station echoes. This radiant location agrees with model predictions to ~1o . The determined geocentric velocity was found to be ~10-15% lower than the model value (17.0 - 19.1 km s^-1 versus 20.4 km s^-1), a discrepancy we attribute to undercorrection for atmospheric deceleration of low density Draconid meteoroids as well as to poor radar radiant geometry during the outburst peak. The mass index at the time of the outburst was determined to be ~ 1.75 using the amplitude distribution of underdense echoes...