黑洞 (hēidòng) is a noun meaning 'black hole,' the astronomical phenomenon where gravity is so strong that nothing can escape. It is a compound of 黑 (black) and 洞 (hole) and is used in scientific and general contexts alike.
科学家拍到了第一张黑洞的照片。
kēxuéjiā pāi dào le dì yī zhāng hēidòng de zhàopiàn.
Scientists captured the first photo of a black hole.
黑洞的引力大到连光都逃不出去。
hēidòng de yǐnlì dà dào lián guāng dōu táo bù chūqù.
A black hole's gravity is so strong that not even light can escape.
他对黑洞的研究非常感兴趣。
tā duì hēidòng de yánjiū fēicháng gǎn xìngqù.
He is very interested in the study of black holes.