Astronomers have detected eight new objects orbiting stars beyond our sun, it was announced Monday. The objects are believed to be six planets and two brown dwarfs (objects that weigh somewhere between a star and a planet).

The discoveries mark a significant increase in the number of "low-mass objects" (planets or brown dwarfs) detected beyond our solar system, bringing the count of such extrasolar objects to more than 40. One of the six planets has the shortest year (time it takes to orbit its star), as well as distance to its star of any known extrasolar planet.

This diagram depicts the size and shapes of the orbits of the eight new objects. The colors indicate the deduced minimum masses of the objects: about one Saturn mass or less (red); between one and three Jupiter masses (green); above 10 Jupiter masses (blue). (Source: ESO)

The eight objects vary widely in mass and other characteristics. The smallest, a planet orbiting star HD 168746, has a deduced a minimum mass only 80 percent that of Saturn. It is only the third extrasolar planet ever detected that may be less massive than Saturn.

The most massive of the eight objects is a brown dwarf around star HD 162060. Its minimum mass is deduced to be 13.7 times that of Jupiter.

A planet orbiting star HD 83443 has the shortest known orbital period, or year, of any extrasolar planet at a mere 2.986 Earth days. Its distance to its star is also the shortest of any known planet: 3.5 million miles (5.7 million kilometers) -- 26 times less than the distance between Earth and the sun.

Furthermore, a small drift in the velocity of star HD 83443 was detected, indicating the star may have an additional low-mass companion.

The team making the observations consisted of Michel Mayor, Francesco Pepe, Didier Queloz, Nuno Santos, Stephane Urdy and Michel Burnet, all of Geneve Observatory in Sauverny, Switzerland.