New App Counts Visible Stars in the Sky


New App Counts Visible Stars in the Sky

30 April 2013

Looking up at the night sky, most of us often wonder how many stars can be seen. An answer to this question will be established with a new app developed by researchers from Germany, which counts the number of all stars visible in the sky, the phys.org website reports.

The app, which can be installed on an Android-powered device, was developed by scientists who are part of the "Loss of the Night" project. The app will be used to measure sky brightness, or skyglow, across the globe and the data gathered will be analysed to better understand light pollution. The data will be also used to track the distribution and changes in sky brightness and help scientists establish potential links to health, biodiversity and energy waste.

In areas still unaffected by human activity the naked eye can see several thousand stars, but there are places, particularly large cities, where just a few stars twinkle in the night sky, commented Dr Christopher Kyba, physicist at the Freie Universit├Ąt.

The "Loss of The Night" project complements the "Globe at Night" citizen science project, which was launched in 2006. It has been financed by the German Ministry of Education and Research.

The app will collect data by asking users to say whether they can see individual stars, and by finding which is the least luminous star the scientists will be able to count the number of visible stars in a particular area and say how bright the sky is as a result. Users can also compare sky brightness in various locations and learn the names of stars and constellations.

Natural light levels are altered by the artificial light going up into the atmosphere, which is changing ecosystems and could even be affecting people's health. However, information about light levels in different parts of the world is scarce, said Dr Annette Krop-Benesch of the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB).