Orbit, emission spectrum, and photometric analysis of two flickering sporadic fireballs

¹ Facultad de Ciencias Experimentales, Universidad de Huelva, 21071 Huelva, Spain
e-mail: jmmadiedo@gmail.com
² Departamento de Física Atómica, Molecular y Nuclear, Facultad de Física, Universidad de Sevilla, 41012 Sevilla, Spain
³ Institut de Ciències de l’Espai (CSIC-IEEC), Campus UAB, Facultat de Ciències, Torre C5-parell-2 a, 08193 Bellaterra, Barcelona, Spain
⁴ Institute of Astrophysics of the Academy of Sciences of the Republic of Tajikistan, Bukhoro, str. 22, 734042 Dushanbe, Tajikistan
⁵ Instituto de Astrofísica de Andalucá, CSIC, Apt. 3004, 18080 Granada, Spain
⁶ Universidad de Castilla-La Mancha, 45071 Toledo, Spain
⁷ La Cañada Observatory (MPC J87), Ávila, Spain

Received: 22 April 2013
Accepted: 4 June 2013

Abstract

We present the observations of two fireballs that exhibit fast and quasi-periodic brightness variations along their atmospheric path. This phenomenon, which is known as “flickering”, is associated to the entry of spinning non-spherical meteoroids into the atmosphere. Both bolides were imaged in the framework of the continuous fireball monitoring and meteor spectroscopy campaigns organized by the SPanish Meteor Network (SPMN) in 2012. Their atmospheric trajectory, radiant, and orbit were calculated. The preatmospheric mass and tensile strength of the parent meteoroids were also estimated, and the rotation of these bodies analyzed on the basis of the photometric behavior of the bolides. Although small (less than 80 grams), a non-zero terminal mass was determined for both events. The emission spectra produced during the ablation of the meteoroids in the atmosphere are also discussed.