"Worlds of the Sky": the first live webcast from a professional telescope of an exoplanet's transit

3 February 2010

On Saturday, February 13, 2010 the exoplanet XO-3b will transit its parent star. Although the phenomenon itself is not spectacular, as this planet orbits its star in less than four days, it will be accompanied by an extraordinary event on Earth: for the first time ever, a professional telescope will observe the transit and the light curve will be webcast live.

The project is called "Worlds of the Sky", quoting the title of a famous book by Camille Flammarion, and is organised by the Brera and Palermo Observatories of the Italian National Institute of Astrophysics, in cooperation with several associations of amateur astronomers.

The unprecedented event will be broadcast live on the website www.crabnebula.it on February 13, from 7 p.m. on. The webcast will allow users around the world to watch the evolution of the light curve of the star XO-3 as the planet passes in front of it, monitored by the 1.34-metre Ruths Telescope of the Brera Observatory in Merate, Italy. The real-time data will be accompanied by comments of astronomers in English, Italian and Chinese.

The organisers intend to involve as many enthusiasts, students and teachers as possible in this novel outreach project, and wish that amateurs around the globe will monitor the event with their own instrumentation, joining efforts in this planetary "guided" observation of an otherworldly event.

The transit of an exoplanet is one of the main techniques used by astronomers to detect planets orbiting stars other than our Sun, monitoring the variations of a star's brightness.

The planet "featured" in this event, XO-3b, was discovered in 2007. It is an extremely massive one, about 13 times as massive as Jupiter, and orbits very closely the star XO-3, also known as GSC 03727-01064, in the constellation Camelopardis. The transit will last about 170 minutes.

A promotional trailer of the event, in English, Italian and Chinese, can be found on YouTube: http://www.youtube.com/watch?v=wsbW5TRo9g0