Francisco Ocaña

The 2011 October Draconids outburst – I. Orbital elements, meteoroid fluxes and 21P/Giacobini–Zinner delivered mass to Earth

We are particularly grateful to all amateur observers that contributed to this study. We acknowledge support from the Spanish Ministry of Science and Innovation (projects AYA2009-13227, AYA2009-14000-C03-01 and AYA2011-26522), Junta de Andalucia (project P09-FQM-4555) and CSIC (grant #201050I043). We also thank the Draconid Recerca en Accio project (granted by Generalitat de Catalunya) in order to promote a cooperative amateur campaign in Catalonia. We also thank Dr Margaret Campell-Brown for many useful suggestions for improving this paper.

Orbits and emission spectra from the 2014 Camelopardalids

We have analysed the meteor activity associated with meteoroids of fresh dust trails of Comet 209P/LINEAR, which produced an outburst of the Camelopardalid meteor shower (IAU code #451, CAM) in 2014 May. With this aim, we have employed an array of high-sensitivity CCD video devices and spectrographs deployed at 10 meteor observing stations in Spain in the framework of the Spanish Meteor Network. Additional meteoroid flux data were obtained by means of two forward-scatter radio systems. The observed peak zenithal hourly rate was much lower than expected, of around 20 meteors h −1 . Despite of the small meteor flux in the optical range, we have obtained precise atmospheric trajectory, radiant and orbital information for 11 meteor and fireball events associated with this stream. The ablation behaviour and low tensile strength calculated for these particles reveal that Camelopardalid meteoroids are very fragile, mostly pristine aggregates with strength similar to that of the Orionids and the Leonids. The mineral grains seem to be glued together by a volatile phase. We also present and discuss two unique emission spectra produced by two Camelopardalid bright meteors. These suggest a non-chondritic nature for these particles, which exhibit Fe depletion in their composition.

Testing sky brightness models against radial dependency: A dense two dimensional survey around the city of Madrid, Spain

Abstract We present a study of the night sky brightness around the extended metropolitan area of Madrid using Sky Quality Meter (SQM) photometers. The map is the first to cover the spatial distribution of the sky brightness in the centre of the Iberian peninsula. These surveys are necessary to test the light pollution models that predict night sky brightness as a function of the location and brightness of the sources of light pollution and the scattering of light in the atmosphere. We describe the data-retrieval methodology, which includes an automated procedure to measure from a moving vehicle in order to speed up the data collection, providing a denser and wider survey than previous works with similar time frames. We compare the night sky brightness map to the nocturnal radiance measured from space by the DMSP satellite. We find that (i) a single source model is not enough to explain the radial evolution of the night sky brightness, despite the predominance of Madrid in size and population and (ii) that the orography of the region should be taken into account when deriving geo-specific models from general first-principles models. We show the tight relationship between these two luminance measures. This finding sets up an alternative roadmap to extended studies over the globe that will not require the local deployment of photometers or trained personnel.

Analysis of a superbolide from a damocloid observed over Spain on 2012 July 13

A superbolide with an estimated absolute magnitude of -20+-1 was seen on July 13, 2012 over the center and south of Spain. This extraordinary event, which was witnessed by numerous casual observers, was recorded in the framework of the continuous fireball monitoring and meteor spectroscopy campaign performed by the SPanish Meteor Network (SPMN). Thus, because of optimal weather conditions, the bolide was imaged from ten meteor observing stations. Here we present the analysis of this magnificent event, which is the brightest fireball ever recorded by our team. The atmospheric trajectory of the bolide and the orbit in the Solar System of the parent meteoroid were obtained. The emission spectrum produced during the ablation of this particle is also discussed. We found that the meteoroid, which was following a Halley Type Comet orbit, was depleted in Na and had a tensile strength one order of magnitude higher than that corresponding to typical cometary materials. By means of orbital analysis tools we have investigated the likely parent body of this particle and the results suggest that the progenitor is a damocloid. The impact area of the hypothetical remnants of the meteoroid is also given and a search for meteorites was performed, but none were found.

Trajectory, orbit, and spectroscopic analysis of a bright fireball observed over Spain on April 13, 2013

On April 13, 2013 a very bright fireball with an absolute magnitude of 13:0 0:5 was recorded over the center of Spain. This sporadic event, which was witnessed by numerous casual observers throughout the whole country, was imaged from seven meteorobserving stations operated by the Spanish Meteor Network (SPMN), and its emission spectrum was also obtained in the framework of our meteor spectroscopy campaign. The atmospheric trajectory of the bolide and the heliocentric orbit of the parent meteoroid are analyzed here. The spectrum reveals a chondritic nature for this particle, which was following a Jupiter family comet orbit before its encounter with the Earth. In addition, the emission spectrum of the meteoric afterglow was recorded during about 0.8 s. The main emission lines appearing in this signal were identified and their evolution with time is also discussed. Afterglow spectra are not abundant in the literature, and these can provide important clues about the physical proceses taking place in meteoric persistent trains.

First results of the Test-Bed Telescopes (TBT) project: Cebreros telescope commissioning

The TBT project is being developed under ESAs General Studies and Technology Programme (GSTP), and shall implement a test-bed for the validation of an autonomous optical observing system in a realistic scenario within the Space Situational Awareness (SSA) programme of the European Space Agency (ESA). The goal of the project is to provide two fully robotic telescopes, which will serve as prototypes for development of a future network. The system consists of two telescopes, one in Spain and the second one in the Southern Hemisphere. The telescope is a fast astrograph with a large Field of View (FoV) of 2.5 x 2.5 square-degrees and a plate scale of 2.2 arcsec/pixel. The tube is mounted on a fast direct-drive mount moving with speed up to 20 degrees per second. The focal plane hosts a 2-port 4K x 4K back-illuminated CCD with readout speeds up to 1MHz per port. All these characteristics ensure good survey performance for transients and fast moving objects. Detection software and hardware are optimised for the detection of NEOs and objects in high Earth orbits (objects moving from 0.1-40 arcsec/second). Nominal exposures are in the range from 2 to 30 seconds, depending on the observational strategy. Part of the validation scenario involves the scheduling concept integrated in the robotic operations for both sensors. Every night it takes all the input needed and prepares a schedule following predefined rules allocating tasks for the telescopes. Telescopes are managed by RTS2 control software, that performs the real-time scheduling of the observation and manages all the devices at the observatory.1 At the end of the night the observing systems report astrometric positions and photometry of the objects detected. The first telescope was installed in Cebreros Satellite Tracking Station in mid-2015. It is currently in the commissioning phase and we present here the first results of the telescope. We evaluate the site characteristics and the performance of the TBT Cebreros telescope in the different modes and strategies. Average residuals for asteroids are under 0.5 arcsecond, while they are around 1 arcsecond for upper-MEO* and GEO† satellites. The survey depth is dimmer than magnitude 18.5 for 30-second exposures with the usual seeing around 4 arcseconds.

Analysis of a superbolide from a Damocloid observed over Spain on July 13, 2012

A superbolide with an estimated absolute magnitude of -20+-1 was seen on July 13, 2012 over the center and south of Spain. This extraordinary event, which was witnessed by numerous casual observers, was recorded in the framework of the continuous fireball monitoring and meteor spectroscopy campaign performed by the SPanish Meteor Network (SPMN). Thus, because of optimal weather conditions, the bolide was imaged from ten meteor observing stations. Here we present the analysis of this magnificent event, which is the brightest fireball ever recorded by our team. The atmospheric trajectory of the bolide and the orbit in the Solar System of the parent meteoroid were obtained. The emission spectrum produced during the ablation of this particle is also discussed. We found that the meteoroid, which was following a Halley Type Comet orbit, was depleted in Na and had a tensile strength one order of magnitude higher than that corresponding to typical cometary materials. By means of orbital analysis tools we have investigated the likely parent body of this particle and the results suggest that the progenitor is a damocloid. The impact area of the hypothetical remnants of the meteoroid is also given and a search for meteorites was performed, but none were found.

Analysis of the September ε-Perseid outburst in 2013

We acknowledge support from the Spanish Ministry of Science and Innovation (projects AYA2015-68646-P and AYA 2015-67175-P).

Low cost multi-purpose balloon-borne platform for wide-field imaging and video observation

Atmosphere layers, especially the troposphere, hinder the astronomical observation. For more than 100 years astronomers have tried observing from balloons to avoid turbulence and extinction. New developments in cardsize computers, RF equipment and satellite navigation have democratised the access to the stratosphere. As a result of a ProAm collaboration with the Daedalus Team we have developed a low-cost multi-purpose platform with stratospheric balloons carrying up to 3 kg of scientific payload. The Daedalus Team is an amateur group that has been launching sounding probes since 2010. Since then the first two authors have provided scienti fic payloads for nighttime flights with the purpose of technology demonstration for astronomical observation. We have successfully observed meteor showers (Geminids 2012, Camelopardalis 2014, Quadrantids 2016 and Lyrids 2016) and city light pollution emission with image and video sensors covering the 400-1000nm range.

THE 2016 QUADRANTIDS BALLOON-BORNE MISSION OVER SPAIN: FULL HD AND COLOUR VIDEORECORDING.

VIDEORECORDING. A. Sanchez de Miguel 1 , F. Ocana 1 , C.E. Tapia Ayuga 1 , J.M. Madiedo 2,3 , J. Zamorano 1 , J. Izquierdo 1 , M. A. Gomez Sanchez-Tirado 4 , F. Ortuno 4 , D. Mayo 4 , R. Raya 4 , A. Conde 4 and P. Leon 4 . 1 Dpto. de Astrofisica y CC. de la Atmosfera, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, 28040 Madrid, Spain, alejasan@ucm.es, 2 Facultad de Ciencias Experimentales, Universidad de Huelva, 21071 Huelva, Spain, madiedo@uhu.es, 3 Dpto. de Fisica Atomica, Molecular y Nuclear, Facultad de Fisica, Universidad de Sevilla, 41012 Sevilla, Spain, 4 Proyecto Daedalus – Asociacion AstroINNOVA, C/Poeta Mohammed Iqbal, 6 1o4, 14010 Cordoba, Spain, astroinnova@astroinnova.org.