Previously, black holes were the undisputed kings of forming powerful jets. Even when only nibbling on a small amount of material, the radio emission that traces the jet outflow from the black hole was relatively bright. In comparison, neutron stars seemed to make relatively puny jets -- the radio emission from their jets was only bright enough to see when they were gobbling material from their companion at a very high rate. A neutron star sedately consuming material was therefore predicted to form only very weak jets, which would be too faint to observe.
Recently, however, combined radio and X-ray observations of the neutron star PSR J1023+0038 completely contradicted this picture.
We describe the evolution of the carbon dust shells around Very Late Thermal Pulse (VLTP) objects as seen at infrared wavelengths. This includes a 20-year overview of the evolution of the dust around Sakurai’s object (to which Olivier made a seminal contribution) and FG Sge. VLTPs may occur during the endpoint of as many as 25% of solar mass stars, and may therefore provide a glimpse of the possible fate of the Sun.
Authors: A. Evans, R. D. Gehrz, L. A. Helton and C. E. Woodward
Astronomers using the Karl G. Jansky Very Large Array (VLA) have discovered jets of material ejected by still-forming young brown dwarfs. The discovery is the first direct evidence that brown dwarfs, intermediate in mass between stars and planets, are produced by a scaled-down version of the same process that produces stars.
The astronomers studied a sample of still-forming brown dwarfs in a star-forming region some 450 light-years from Earth in the constellation Taurus, and found that four of them have the type of jets emitted by more-massive stars during their formation.
"This is the first time that such jets have been found coming from brown dwarfs at such an early stage of their formation, and shows that they form in a way similar to that of stars," said Oscar Morata, of the Institute of Astronomy and Astrophysics of the Academia Sinica in Taiwan.
Gaia14aae contains large amounts of helium, but no hydrogen, which is highly unusual as hydrogen is the most common element in the Universe. The lack of hydrogen allowed them to classify Gaia14aae as a very rare type of system known as an AM Canum Venaticorum (AM CVn), a type of Cataclysmic Variable system where both stars have lost all of their hydrogen. This is the first known AM CVn system where one star totally eclipses the other.
“It’s really cool that the first time that one of these systems was discovered to have one star completely eclipsing the other, that it was amateur astronomers who made the discovery and alerted us,” said Campbell. “This really highlights the vital contribution that amateur astronomers make to cutting edge scientific research.”