nebula tagged posts

When astronomers looked at a stellar pair at the heart of a stunning cloud of gas and dust, they were in for a surprise. Star pairs are typically very similar, like twins, but in HD 148937, one star appears younger and, unlike the other, is magnetic.

New data from the European Southern Observatory (ESO) suggest there were originally three stars in the system, until two of them clashed and merged. This violent event created the surrounding cloud and forever altered the system’s fate.

“When doing background reading, I was struck by how special this system seemed,” says Abigail Frost, an astronomer at ESO in Chile and lead author of the study, “A magnetic massive star has experienced a stellar merger,” published in Science.

The system, HD 148937, is located about 3800 light-year...

an artistic view of the accretion disc surrounding the black hole V404 Cygni, where the intense wind detected by GTC becomes evident. Credit: Gabriel Pérez, SMM (IAC)

An international team of astrophysicists have detected an intense wind from one of the closest known black holes to the Earth. During observations of V404 Cygni, which went into a bright and violent outburst in June 2015 after more than 25 years of quiescence, the team began taking optical measurements of the black hole’s accretion disc using the 10.4m Gran Telescopio CANARIAS (GTC) – the biggest optical-infrared telescope in the world in the Roque de los Muchachos Observatory (Garafía, La Palma) in the Canary Islands.

The results show a wind of neutral material (unionised H and He), formed in the outer layers of the accret...

Artist impression of a Fast Radio Burst (FRB) reaching Earth. The colors represent the burst arriving at different radio wavelengths, with long wavelengths (red) arriving several seconds after short wavelengths (blue). This delay is called dispersion and occurs when radio waves travel through cosmic plasma. Credit: Jingchuan Yu, Beijing Planetarium

Origin of a Fast Radio Burst has been tied to to a highly magnetized, gas-filled region of space, providing a new hint in the decade-long quest to explain the mysterious radio pulses. “We now know that the energy from this particular burst passed through a dense magnetized field shortly after it formed,” says Kiyoshi Masui...