Octal is a light pollution initiative part of the Stars4All program funded by the European Union H2020 Programme 688135. STARS4ALL aims at creating conscience in the public about the negative effects of artificial light in human beings, biodiversity, stars visibility, security, and energy wastage. Following this aim, Octal is born with the objective of developing citizen data science experiences in which people from around the world could participate in workshops to receive training on collecting, analysing and visualising light pollution data.


These workshops have different training strategies, such as creating night sky observations where communities collect data in situ to measure light pollution using an Octal designed device; or workshops where people analyse their own data, and other publicly available information on light pollution to create data visualisations.


Octal develops night sky observation experiences by using an open source spectrometer. This device takes qualitative and quantitative measures of light pollution in situ. Originally created by Public Lab, this spectrometer was modified to measure light pollution using a mobile phone in two ways; counting starts, and measuring the light spectrum. The data collected through the device is then analysed in the Octal workshops to determine and compare levels of light pollution in different urban areas.

Who support us

Octal is funded by European Union’s Horizon 2020 through Stars4All initiative. Also, is supported by Common Action Forum and Asociación de Consumidores Responsables.

Team and Collaborators

Our team and collaborators is composed by a group of volunteers experts in different fields.