Neutron Star Powers Ultraluminous X-rays
It turns out that neutron stars — not black holes — power at least some ultraluminous X-ray sources.
No Big Black Hole for Two ULXs
Two new studies suggest that ultraluminous X-ray sources are not all created by beefy black holes.
X-ray Outburst in Spiral Galaxy M83
Astronomers have spotted an unusual "ultraluminous" burst of X-rays coming from the otherwise barren region between the grand spiral arms of Messier 83.