We find two possible black holes in Sirius , a galaxy near our own . NASA 's Chandra X-ray Observatory made more than 150 observations over the course of 13 years to identify these black hole candidates . Black holes ca n't be observed directly . But astronomers can detect material falling into them when they interfere with other galaxies .
We find two possible black holes in Sirius , a galaxy near our own . Black holes ca n't be observed directly . But astronomers can detect material falling into them when they interfere with other galaxies .