Figure: Comparison between the solar and 2M1207 systems

This picture shows for illustration a comparison between the solar system and the brown dwarf object 2M1207 system with its possible planet at 55 AU distance. The sizes of the objects are drawn to the same scale, but the distances have been strongly compressed.

Taking into account the infrared colours and the spectral data available for the Giant Planet Candidate Companion (GPCC), evolutionary model calculations point to a 5 jupiter-mass planet, about 55 times more distant from 2M1207 than the Earth is from the Sun (55 AU). The surface temperature appears to be about 10 times hotter than Jupiter, about 1000 ^oC; this is easily explained by the amount of energy that must be liberated during the current rate of contraction of this young object (indeed, the much older giant planet Jupiter is still producing energy in its interior).

The astronomers will now continue their research to confirm or deny whether they have in fact discovered an exoplanet. Over the next few years, they expect to establish beyond doubt whether the object is indeed a planet in orbit around the brown dwarf 2M1207 by watching how the two objects move through space and to learn whether or not they move together. They will also measure the brightness of the GPCC at multiple wavelengths and more spectral observations may be attempted.

There is no doubt that future programmes to image exoplanets around nearby stars, either from the ground with extremely large telescopes equipped with specially designed adaptive optics, or from space with special planet-finder telescopes, will greatly profit from current technological achievements.

Credit: European Southern Observatory (ESO)

http://www.eso.org/outreach/press-rel/pr-2004/pr-23-04.html