Impressive haul for HARPS
15 Sep 2011 by Evoluted New Media
Exoplanet hunter HARPS has discovered an impressive haul of more than 50 new exoplanets orbiting nearby stars, including 16 super-Earths – one orbiting at the edge of the habitable zone of its star.
This is the largest number of such planets ever announced at one time, and makes HARPS – a spectrograph on the 3.6m telescope at ESO’s La Silla Observatory in Chile – the world’s most successful planet finder.
“The harvest of discoveries from HARPS has exceeded all expectations and includes an exceptionally rich population of super-Earths and Neptune-type planets hosted by stars very similar to our Sun,” said HARPS team leader Michel Mayor. “And even better – new results show that the pace of discovery is accelerating.”
Using the radial velocity technique, HARPS has observed 376 Sun-like stars and discovered more than 150 planets. It has discovered about two-thirds of all known exoplanets with masses less than that of Neptune, and that 40% of stars have at least one planet lighter than Saturn.
One of the planets – HB 85512 b – is estimated to be about 3.6 times the mass of Earth and is located at the edge of a habitable zone, where liquid water, and perhaps even life, could potentially exist.
“This is the lowest-mass confirmed planet discovered by the radial velocity method that potentially lies in the habitable zone of its star, and the second low-mass planet discovered by HARPS inside the habitable zone,” said Lisa Kaltenegge, an expert on the habitability of exoplanets.
With upgrades to both its hardware and software HARPS is being pushed to the next level of stability and sensitivity to search for rocky planets that could support life. Ten nearby stars similar to the Sun were selected for a new survey – and are already known to be suitable for extremely precise radial velocity measurements.
“These planets will be among the best targets for future space telescopes to look for signs of life in the planet’s atmosphere by looking for chemical signatures such as evidence of oxygen,” said Francesco Pepe.
