It's possible that most stars have far more time than previously thought to produce planets.

A new study contends that planet-forming gas and dust discs live millions of years longer around orange and red dwarf stars than previously thought.

According to a study published on October 6 at arXiv.org, planet-making discs around young stars typically last for 5 million to 10 million years. Based on a survey of surrounding young star clusters, that disc lifetime is far longer than the earlier estimate of 1 million to 3 million years.

The formation of planets must occur within one to three megayears, according to astrophysicist Susanne Pfalzner. The percentage of young stars of various ages that still have discs has been used in previous research to estimate disc lifetimes; this has been done, in instance, by monitoring star clusters with known ages. However, Pfalzner and her associates made a strange discovery: The estimated disc lifetime of a star cluster decreases with increasing distance from Earth.

Pfalzner and her colleagues found that the proportion of stars with planet-making discs was significantly higher than that suggested by earlier studies. They limited their analysis to the nearest young star clusters, those that are within 650 light-years of Earth. According to her, this research revealed that low-mass stars have disc lifetimes that are between 5 and 10 megayears longer than what astronomers had previously thought. It is known that discs surrounding greater mass stars scatter more quickly than this, maybe because the stronger light from their suns accelerates the ejection of gas and dust.

Lvaro Ribas, an astronomer at the University of Cambridge who was not involved with the investigation, says 'I wouldn't claim that this is solid proof' for such lengthy disc lifetimes around orange and red dwarfs. However, it's quite convincing.

He hopes to conduct investigations of farther-off star clusters, maybe with the James Webb Space Telescope, to ascertain the proportion of the weakest stars that have maintained their planet-forming discs for between 5 million and 20 million years in order to support the findings. 

According to Pfalzner, there may be a distinction between our solar system and that of the majority of red dwarfs if the discs surrounding the lowest mass stars do indeed have extended lifetimes. Gas giants like Jupiter and Saturn, which have diameters roughly equal to that of Earth, are frequently absent from the latter. Instead, such stars usually host a large number of four times the size of Earth ice giants like Uranus and Neptune.