A decadal survey of the Daytime Arietid meteor shower using the Canadian Meteor Orbit Radar

• Published in: Monthly notices of the Royal Astronomical Society 2015-01, Vol.446 (2), p.1625-1640
• Main Authors: Bruzzone, J. S., Brown, P., Weryk, R. J., Campbell-Brown, M. D.
• Format: Article
• Language: English
• Subjects: Astronomy; Meteors & meteorites; Orbits; Radar
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/stu2200

We present results from a 12 year survey of the Daytime Arietid meteor shower using the Canadian Meteor Orbit Radar, a VHF backscattering orbital meteor radar, covering the interval 2002-2013. This survey recorded more than 2 x 10... Daytime Arietid orbits having representative masses of 8 x 10... kg and sizes of ...0.4 mm. The core activity for the Arietids is found in the range 73 ...5 ≤ ... ≤ 84 ...5 and shows a broad 4-d maximum centred near ... = 80 ...5 of 0.04 meteoroids km... h... producing meteors of equivalent radio magnitude of +6.5 from a mean radiant at α... = 44 ...9 ± 1 ...1, ... = 25 ...5 ± 1 ...0. During the plateau of shower peak activity, the mass index of the stream reaches a minimum with s = 1.6-1.7. Contamination from another nearby shower (likely the Daytime Zeta Perseids) and/or sub-streams showing different orbits compared to the core of the stream is evident in the interval 60 ...5 ≤ ... ≤ 71 ...5. Similar contamination beyond ... = 84 ...5 may be due to the Helion sporadic source. We also characterized the deceleration profiles for Daytime Arietid meteor echoes using several independent speed techniques including Fresnel pre-t..., Fresnel amplitude oscillation and time-of-flight speeds which together with modelling produced a best estimate for the stream's out-of-atmosphere speed of v... = 40.5 ± 0.7 km s... The mean radar orbit from our study is noticeably smaller in semi-major axis and eccentricity than is found for larger Arietids measured with optical systems, a difference which if real indicates a particle-size sorting of the stream orbit. The broad activity maximum, long duration of activity and particle-size dependence of the orbital elements suggest the stream is too old to have been solely formed during the breakup of the parent comet of the Marsden sunskirters about a millennium ago as proposed by Sekanina & Chodas. (ProQuest: ... denotes formulae/symbols omitted.)