White dwarfs - dead stars - may actually have planets around them that can support life, according to prof. Dan Maoz of Tel Aviv University's School of Physics and Astronomy.

Technology available in the next few decades can help us find evidence of life-supporting systems on these planets, especially the presence of certain biomarkers such as oxygen and methane, says a report published by prof. Maoz and prof. Avi Loeb, Director of Harvard University's Institute for Theory and Computation.

NASA is set to launch the James Webb Space Telescope (JWST) in 2018 and researchers say that this program will provide technology to get information about conditions on the planets around the dwarfs.

Previous research has already found that white dwarfs have significant levels of heavy elements and have planets that are rocky. At least one of the 500 of the closest white dwarfs could have a planet that can support life, researchers estimate.

"In the quest for extraterrestrial biological signatures, the first stars we study should be white dwarfs," said prof. Loeb. Also, Maoz added that these planets may have "signs of life".

According to researchers, searching for planets with life around white dwarfs is easier than looking for planets around other stars, because white dwarfs don't blind the observer with light.

"The novelty of our idea is that, if the parent star is a white dwarf, whose size is comparable to that of an Earth-sized planet, that glare is greatly reduced, and we can now realistically contemplate seeing the oxygen biomarker," Maoz said in a news release.

The detection of oxygen and other biomarkers would be crucial for the mission, as these elements show whether or not the planet can support life. NASA's JWST is designed to look into the infra-red region of the light spectrum that has these biomarkers.

The researchers' work is published in the journal Monthly Notices of the Royal Astronomical Society.