根据输入的新闻报道，使用自然语言生成一段总结该报道内容的简短摘要。
以下是从BBC新闻网站上获取的新闻报道： 

Astronomers detect signal from closest star to our solar system.
New observations suggest Proxima Centauri, the star closest to our Sun, may have a second planet.
Researchers detected signs of a possible "Super Earth" orbiting around Proxima Centauri, which is just 4.2 light-years away.
Proxima Centauri is already known to host one planet, Proxima b, but the latest discovery raises the possibility of a second, larger planet.
A possible "Super Earth" planet may exist in our closest star system, Proxima Centauri, according to new observations made by astronomers. This adds to the already known planet, Proxima b, orbiting around the star just 4.2 light-years away from our solar system.