A group of astronomers led by Pierre-Olivier Lagage have discovered a planetary disk around the large and young star HD 97048. Their results was published yesterday in the online science journal Science Express. The star, located in the dark cloud of newly born stars, Chameleon I, 600 light-years away, is 2.5 times as massive as our sun and shines 40 times as brightly.

Planetary disks are the humongous rings of dust and gas from which planets are believed to form, as individual lumps of dust gathers mass enough to scoop up the material in their orbits. Disks have been observed before, but never around a star as massive and young as HD 97048. The star is just a few million years old, which is almost nothing compared to the 4.5 billion years of the sun.

The astronomers observed the star through ESO's (the European Organisation for Astronomical Research of the Southern Hemisphere) aptly titled 'Very Large Telescope'. By using the telescopes VISIR instrument, an infrared spectrometer and imager specially designed with the study of hot dust and gaseous components in mind, they were able to map out the disc of gas and dust around the star.

The disc stretches out to an immense distance of around 360 astronomical units (1 AU is the distance from earth to the sun), and it contains an enormous amount of gas and dust: enough gas for 10 gas giants the size of Jupiter and dust enough to form 50 Earths.

Pierre-Olivier Lagage believes that so-called planetary embryos may be present within the inner parts of the disc, and he is planning to follow up the discovery with more observations at higher resolutions. But due to the immense distances of the universe, and the challenges of picking up an object the size of a planet next to a giant, luminous star, it will most likely be impossible to observe any of the proto-planets that might be starting their life inside the disc.

More than 200 exo-planets have been found so far, but our knowledge of planetary formation is still very limited. The newly found disc might finally give astronomers an opportunity to witness the conditions prevailing prior to (or during) planet formation.