* Astronomy

Title: Meteoroid Orbits from Video Meteors. The Case of the Geminid Stream
Author: Maria Hajdukova Jr., Pavel Koten, Leonard Kornos, Juraj Toth

We use the Slovak and Czech video meteor observations, as well as video meteoroid orbits collected in the CAMS, SonotaCo, EDMOND and DMS catalogues, for an analysis of the distribution of meteoroid orbits within the stream of the Geminids and of the dispersion of their radiants. We concentrate on the influence of the measurement errors on the precision of the orbits obtained from the video networks that are based on various meteor-detection software packages and various meteor orbital element softwares. The observed orbital dispersions in the Geminid stream described by the median absolute deviation range from 0.029 to 0.042 1/AU for the video catalogues. The distribution of the semi-major axes of video meteors in all the databases, except for the Ondrejov (Czech) data, seem to be systematically biased in comparison with the photographic and radio meteors. The determined velocities of the video data are underestimated, probably as a consequence of the methods used for the positional and velocity measurements. The largest shift is observed in the EDMOND and SonotaCo catalogues. Except for the measurement errors which influence the analyses and their interpretations, we also point out the problem of the uncertainties of the numerical integration procedures that influence the simulations' results. Several experimental integrations of the Geminids parent asteroid, which we performed from the present to the past and then back to the year 2015, showed that a complete reproduction, including also the mean anomaly, is only possible for a time span of about 2700 years.

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Star Gazing: Geminid Meteor shower awes spectators in China

Spoiler

A Good Year To View The Geminid Meteor Shower

This year's Geminid meteor display, the best of the annual meteor showers, will be visible from approximately the 7th to 17th December, peaking on the evening of the 14th. The meteors, or 'shooting stars', which are best seen any time from late evening onwards, emanate from an area of the sky known as the 'radiant', which lies in the winter constellation Gemini (the 'twins'). This rises after sunset and remains above the horizon all night. For those who have never seen a meteor, this year provides one of the best opportunities, as there will no interfering moonlight.
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