Because a neutron star's solid crust is locked to its intense magnetic field, a disruption of one immediately affects the other. A fracture in the crust will lead to a reshuffling of the magnetic field, or a sudden reorganization of the magnetic field may instead crack the surface. Either way, the changes trigger a sudden release of stored energy via powerful bursts that vibrate the crust, a motion that becomes imprinted on the burst’s gamma-ray and X-ray signals.
It takes an incredible amount of energy to convulse a neutron star. The closest comparison on Earth is the 9.5-magnitude Chilean earthquake of 1960, which ranks as the most powerful ever recorded on the standard scale used by seismologists. On that scale, said Watts, a starquake associated with a magnetar giant flare would reach magnitude 23.
Massive black holes spewing out radio-frequency-emitting particles at near-light speed can block formation of new stars in aging galaxies, a study has found.
The research provides crucial new evidence that it is these jets of “radio-frequency feedback” streaming from mature galaxies’ central black holes that prevent hot free gas from cooling and collapsing into baby stars.
“When you look into the past history of the universe, you see these galaxies building stars,” said Tobias Marriage, assistant professor of physics and astronomy at Johns Hopkins and co-lead author of the study. “At some point, they stop forming stars and the question is: Why? Basically, these active black holes give a reason for why stars stop forming in the universe.”
A group of researchers led by Melina Bersten of Kavli IPMU recently presented a model that provides the first characterization of the progenitor for a hydrogen-deficient supernova. Their model predicts that a bright hot star, which is the binary companion to an exploding object, remains after the explosion. To verify their theory, the group secured observation time with the Hubble Space Telescope (HST) to search for such a remaining star. Their findings, which are reported in the October 2014 issue of The Astronomical Journal, have important implications for the evolution of massive stars.
During the last years, many observational studies have revealed that binaries play an active role in the shaping of non spherical planetary nebulae. We review the different works that lead to the direct or indirect evidence for the presence of binary companions during the Asymptotic Giant Branch, proto-Planetary Nebula and Planetary Nebula phases. We also discuss how these binaries can influence the stellar evolution and possible future directions in the field.