(CNN) -- Thirty-two planets have been discovered outside
Earth's solar system through the use of a high-precision instrument
installed at a Chilean telescope, an international team announced
Monday.
This artist's rendering shows one of the so-called exoplanets, or planets outside our solar system.
The existence of the so-called exoplanets -- planets outside our solar
system -- was announced at the European Southern Observatory/Center for
Astrophysics, University of Porto conference in Porto, Portugal,
according to a statement issued by the observatory.
The
announcement was made by a consortium of international researchers,
headed by the Geneva Observatory, who built the High Accuracy Radial
Velocity Planet Searcher, or HARPS. The device can detect slight
wobbles of stars as they respond to tugs from exoplanets' gravity. That
tactic, known as the radial velocity method, "has been the most
prolific method in the search for exoplanets," according to the
European Southern Observatory statement.
The instrument detects movements as small as 3.5 km/hr (2.1 mph), a slow walking pace, the observatory said.
With the discovery, the tally of new exoplanets found by HARPS is now
at 75, out of about 400 known exoplanets, the organization said,
"cementing HARPS's position as the world's foremost exoplanet hunter."
The 75
planets are in 30 planetary systems, the European Southern Observatory said.
"HARPS is a unique, extremely high precision instrument that [is] ideal
for discovering alien worlds," Stephane Udry of Geneva University, who
made the announcement on behalf of the international consortium that
built the instrument, said in the observatory statement. "We have now
completed our initial five-year program, which has succeeded well
beyond our expectations."
"We are on the road," Udry told CNN in a phone call from Portugal. "The
end of the road is finding life and other planets like our own, but we
have to go step by step."
HARPS has also boosted the discovery
of so-called super-Earths -- planets with a mass a few times that of
Earth. Of the 28 super-Earths known, HARPS facilitated the discovery of
24, the European Southern Observatory statement said. Most reside in
multiplanet systems, with up to five planets per system.
Although only 32 were announced Monday, the team knows of many more
exoplanets, although more observation is needed before they are
formally announced and papers are written about them. "We have tons of
them," Udry said.
In return for building HARPS, the consortium
was provided 100 observing nights per year over five years to search
for exoplanets, one of the most ambitious searches ever implemented on
a global basis, the
European Southern Observatory said.
"These observations have given astronomers a great insight into the
diversity of planetary system and help us understand how they can
form," team member Nuno Santos said in the statement.
The HARPS
findings confirm the predictions of those who study planetary
formation, Udry said. "Moreover, those models are also predicting even
more ... Earth-type planets."
An important find for the study of
planet formation was that three exoplanets were around stars that are
metal-deficient, Udry said. Metal-deficient stars are thought to be
less favorable for planet formation; however, planets the size of
several Jupiters were found orbiting such deficient stars, the European
Southern Observatory said.
In addition, the discovery gives "a very strong push" to projects attempting to find and study such exoplanets, Udry said.
According to its Web site, the European Southern Observatory is the foremost intergovernmental
astronomy
organization in Europe and describes itself as the "world's most
productive astronomical observatory. " It is supported by 14 European
countries