On the activity of the γ-Ursae Minorids meteoroid stream in 2010 and 2011

Accurate orbital data obtained for the recently discovered γ -Ursae Minorids meteoroid stream during the 2010 and 2011 Spanish Meteor Network and Finnish Fireball Network observing campaigns are presented. In particular, we focus on an outburst detected in 2010 and on the analysis of the first emission spectrum recorded for a member of this meteoroid stream. An array of high-sensitivity CCD video devices operating from different locations in Spain and Finland was used to perform this study. We have obtained precise trajectory, radiant and orbital information for seven members of this stream. Considerations about its likely parent body based on orbital dissimilarity criteria are made. We also present an estimation of the tensile strength for these meteoroids and a unique emission spectrum of a γ -Ursae Minorid fireball that reveals that the main rocky components have chondritic abundances.We acknowledge Timo Kantola, Mika Jarvinen, Ari Jokinen and Ilkka Yrjola for the images recorded from Finland during the 2010 GUM outburst. Besides, we thank Fundacion AstroHita for its support in the establishment and operation of the automated meteor observing station located at La Hita Astronomical Observatory (La Puebla de Almoradiel, Toledo, Spain). We also acknowledge support from the Spanish Ministry of Science and Innovation (projects AYA2009-13227, AYA2009-14000-C03-01, AYA2011-26522 and AYA2011-30106-C02-01), CSIC (grant #201050I043) and Junta de Andalucia (project P09-FQM-4555)