Quasi-Periodic Oscillation

Black Holes

Seeing a Black Hole’s Gravitational Vortex

New observations solve a 30-year-old puzzle of mysterious signals from around black holes.

Quasi-Periodic Oscillation (QPO)

Star-Shredders in Action

In the cover story of the June 2013 issue, Suvi Gezari takes us into the den of hibernating black holes, showing us what happens when a star tickles the nose of a powerful beast: the black hole rips the unlucky star apart, lighting a flare that can be seen from…

Milky Way

Black Hole Shoots Bullets

Observations of a black hole that spat out twin blobs of superhot material may help astronomers understand how the mysterious beasts create powerful jets that shoot out from their poles. The blobs appeared just as the system went quiet in X-rays.


Heartbeat Suggests Smallest Black Hole

Strange, regular pulses from a black hole-star binary system suggest that the smallest black hole yet discovered lies behind the signals. Similarities between it and another known mystery object may mean the black holes are hiccuping as they eat.