Authors: Josep Martí (University of Jaén, Spain), Pedro L. Luque-Escamilla (University of Jaén, Spain), and José Martínez Aroza (University of Granada, Spain)

Purpose

Nowadays, people living in urban areas are often unaware of the beautiful spectacle that the night sky offers to them even if surrounded by strong city lights. The purpose of our Project is to bring real time views of the sky to the general public of any age in order to enhance their interest about Science in general and Astronomy in particular. While doing so, we are also contributing to rise their social concern about the light pollution problem and its environmental consequences.

In order to achieve this goal, we have set up a web-based interface which simultaneously displays a real time view of the whole sky together with a matching, computer-generated sky map (see http://aljayani.ujaen.es). These comparative views are updated every minute 24 hours a day, thus allowing any user to identify the main celestial objects visible at any time. Moreover, the videos of the previous day are automatically available together with a gallery of relevant events previously recorded by the camera. Among the most interesting phenomena so far detected, we can quote: satellite tacking (e.g. the International Space Sation), bright meteors (e.g. Geminids), eclipses, storms and other meteorological episodes, bird watching, and so on.

The system is fully autonomous and runs continuously almost without human assistance. The real images are taken using an All-Sky camera located at the Astronomical Observatory of the University of Jaén, in the outskirts of the Jaen city. An interesting feature of our system is the implementation of an image-processing algorithm to suppress most of the background light pollution. The procedure works in a similar way as infrared astronomers estimate and remove the natural background sky emission by median-filtering a set of consecutive images. In this way we are able to reveal features as faint as the Milky Way, that otherwise would remain hidden in the unprocessed images. Bringing up these enhanced celestial views of an urban sky contributes to the awareness about the light pollution problem among the on-line users.

Our project provides an excellent tool for teaching of astronomical concepts at very different levels. In fact, we use it for both degree courses and outreach talks to a broad range of audiences from children to older adults. Moreover, the project has also been useful to professional astronomers involved the study of meteors and fireballs. In particular, we have been requested to provide images of fireball detections to the Spanish Meteor and Fireball Network, such as the event of 28th April 2011 shown in our Gallery whose atmospheric ingress took place just above Jaén. Astronomy students at our university are also participating in this kind of research by carefully inspecting the processed videos recorded in every clear night searching for possible meteor and fireball detections.

Impact

The web traffic of the aljayani.ujaen.es server since its opening in 2010 October is currently exceeding 50,000 visits from all over the world, with an average of 100 visits daily. This is a significant figure considering that we are located in a relatively small institution and that most of the outreach connected with this project was at a local level. The name of our computer server was chosen to honour the 11th century arab astronomer Ibn-Muadh Al-Jayyani who lived and worked in Jaén. When typing this name in the Google search engine, our Project remarkably appears from first to third position thus reflecting the impact of our initiative.

The authors have also undertaken a wide effort to ensure outreach to the media (tv, radio, and newspapers) in the Spanish province of Jaén and the Andalusian region (see additional file). The '3rd Scientific Outreach Plan of the University of Jaén' has also used images taken from our web page for illustrative purposes of the 2011 booklet (available at http://www.ujaen.es/serv/viccom/ucc/IIIplanDivulgacionCientifica.pdf ). Even a publication in a professional conference should also be mentioned here where the background removal algorithm is described (Luque-Escamilla, P. L., Martí, J., Martínez-Aroza, J., 2011, Fighting light pollution with an urban all-sky astronomical camera, MAMERN11: 4th International Conference on Approximation Methods and Numerical Modelling in Environment and Natural Resources Saidia (Morocco), May 23-26, 2011).

Originality

Although on-line sky cameras are available through the world wide web, the originality of our Project is based on:

i) All images and videos are immediately public and accessible to any one.

ii) A comparison sky-map is simultaneously provided with the real view. It can also be downloaded for printing with high-resolution. The option also exists to generate it for any place in the world and any time past or future.

iii) Our All-sky camera is located in an urban area under the same observing conditions to the common people, while most similar projects are placed in professional observatories with extremely good skies.

iv) We also make available the results of our light-pollution removal algorithm as a ‘light pollution-free' video for every nigh.

Sustainability

The web-based system to bring the Jaén night skies to any one has been operative since two years and a half, and will remain on-line in the future. As the cost of the project is relatively low (circa 3000 euro), and almost no human assistance is required for maintenance, plans exist to set up similar systems in other locations. These would include a professional astronomical observatory for real time comparison of different light-pollution environments, and even a Southern hemisphere twin to provide users with a real time view of the whole celestial sphere.

Our project is not complicated in terms of hardware and so it is easily reproducible by any other institution. Moreover we are willing to provide all necessary advice and software to any one interested.

Acknowledgements

This project was sponsored by the “Vicerrectorado de Tecnologías de la Información y Comunicación” at the University of Jaén (Spain).