Tonight's Sky
Sun
Sun
Moon
Moon
Mercury
Mercury
Venus
Venus
Mars
Mars
Jupiter
Jupiter
Saturn
Saturn

Tonight's Sky — Change location

OR

Searching...

Tonight's Sky — Select location

Tonight's Sky — Enter coordinates

° '
° '

When scientists talk about the rotation of a black hole, what are they referring to? If we can’t see a black hole, how can we tell if it rotates?

Mike Rhodes, San Juan Capistrano, California
black-hole
This artist's concept depicts a supermassive black hole at the center of a galaxy. Illustration: NASA/JPL-Caltech
A spinning black hole has a different gravitational field than a non-spinning one. Spin is an intrinsic aspect of the black hole. A spinning black hole will radiate more energy than a non-spinning one. The accretion disk’s temperature also increases the faster the black hole spins. We can observe these differences in the X-ray spectra of accreting black holes.

Another method involves measuring the speed that matter rotates around the black hole.

Already a subscriber? Register now!

Registration is FREE and takes only a few seconds to complete. If you are already registered on Astronomy.com, please log in below.
ADVERTISEMENT

FREE EMAIL NEWSLETTER

Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter.

ADVERTISEMENT
ADVERTISEMENT
BoxProductcovernov

Click here to receive a FREE e-Guide exclusively from Astronomy magazine.

Find us on Facebook

Loading...