黑洞很难被发现
Black holes are hard to find. They have such strong gravity that light can’t escape them, so scientists must rely on clues from their surroundings to find them.
When a star weighing more than 20 times the Sun runs out of fuel, it collapses into a black hole. Scientists estimate that there are tens of millions of these black holes dotted around the Milky Way, but so far we’ve only identified a few dozen.
This image from 2001 is an artist’s impression of a black hole accretion disk. Around many black holes is an accretion disk of material emitting energy as it falls into the black hole.
Image Credit: XMM-Newton, ESA, NASA
黑洞很难被发现。它们有很强的引力，光线无法逃脱，所以科学家必须依靠它们周围环境的线索来找到它们。
当一颗重量超过太阳20倍的恒星耗尽燃料时，它就会坍缩成黑洞。科学家们估计，银河系周围分布着数千万个这样的黑洞，但到目前为止，我们只发现了几十个。
这张2001年的照片是一位艺术家对黑洞吸积盘的印象。许多黑洞周围都有一个吸积盘，当物质落入黑洞时，它会释放能量。
图片来源：XMM-Newton, ESA, NASA