Observations of the new Camelopardalids meteor shower using a 38.9 MHz radar at Mohe, China

摘要

The Camelopardalids meteor shower was predicted to occur for the first time on 24 May 2014, based on optical observations of the comet 209P/LINEAR. Using a 38.9 MHz meteor radar located at Mohe, China, we were able to detect approximately 590 shower meteors originating from an average pre-infall radiant of R.A. = 129.1 degrees +/- 9.8 degrees, declination = 79.4 degrees +/- 1.6 degrees (J2000) with a geocentric velocity of 16.0 +/- 1.6 km s(-1). Measurements of the shower duration, direction, velocity, and individual meteor detection heights facilitated a detailed analysis of the parent debris stream. Orbital parameters were calculated including a semi-major axis of 2.86 AU, eccentricity of 0.659, and inclination of 21.1 degrees. Combining orbital parameters with the shower activity duration FWHM of 5.09 h, it was found that the stream has a FWHM of at least 211,000 km at 1 AU, as measured perpendicular to the direction of orbital motion. A comparison of shower meteor detection heights and diffusion coefficient estimates with the sporadic background is consistent the prediction of Ye and Wiegert (Ye, (2, Wiegert, P. [2014]. Mon. Not. R. Astron. Soc. 437, 3283-3287) that Camelopardalid meteoroids are biased towards larger sizes or that Cameloppardalid meteoroids are less fragile than sporadic background meteoroids. (C) 2015 Elsevier Inc. All rights reserved.