Astronomers found that every 23.1 minutes, one of 65 orbiting space rocks passed in front of a white dwarf star. This precise pattern suggests that a planet may be corralling these rocks
Illustration of the white dwarf star WD 1054-226 orbited by clouds of planetary debris and a major planet in the habitable zoneA distant white dwarf is surrounded by space rocks marching in perfect time. This observation offers hints of what may be the first planet we have detected in the habitable zone of one of, suggesting that they might be just as good for life as bigger, younger stars.
“A lot of people think of a white dwarf as a dead system or a dead end, but this tells us that there is a lot of stuff going on around white dwarfs,” saysHe and his colleagues spotted these hints while observing a star called WD 1054-226, which lies about 118 light years away, using several powerful telescopes. They found that something appeared to be regularly passing in front of the star, causing dips in its light. The biggest dip happened every 23.
The researchers calculated that the orbiting objects are about 2.6 million kilometres from the star – about 4 per cent of the distance between Mercury and the sun – putting their temperatures at around 50°C, which is right in the middle of the range for liquid water. This means that if there is a planet there, it could have the right temperature for oceans and maybe even life.