Stars

The black hole V404 Cygni swings like a spinning top

0

An article published in the journal “Nature” reports the observation of a jet of materials emitted by the black hole V404 Cygni which changed orientation in no more than a few hours. A team led by James Miller-Jones of the Curtin University node of the International Center for Radio Astronomy Research (ICRAR), Australia, used the Very Long Baseline Array radio telescopes to study the area around the black hole during one of its periodic bursts of considerable intensity. This made it possible to observe for the first time jets of materials changing orientation in a few hours or even minutes.

The extent of the expansion of the universe is increasingly precise and stresses the discrepancy between the measurements

0

An article published in “The Astrophysical Journal” reports a new measurement of the expansion of the universe, which is approximately 9% faster than the estimates made by studying the early universe. A team of astronomers led by Nobel laureate Adam Riess combined observations made with the Hubble Space Telescope of 70 variable stars called Cepheid variables used for measurements with others conducted by the Araucaria project to obtain extremely precise measurements of their brightness. The discrepancy between the measurements of the expansion of the near universe and those of the early universe remains and it’s important to improve the measurements to obtain clues to the origin of the discrepancy.

Tides and proton flows for the planets of the TRAPPIST-1 system

0

Two articles published in “The Astrophysical Journal” describe as many researches on the possibility that at least some of the seven rocky planets of the ultra-cool dwarf star TRAPPIST-1’s system can be habitable. Two researchers from the University of Arizona’s Lunar and Planetary Laboratory examined the effects gravity of planets has on its neighbors. A team from the Center for Astrophysics (CfA) of Harvard University and Smithsonian Institution examined the effects that high-energy protons emitted by the star may have on its planets.

The first Earth-sized exoplanet identified thanks to the TESS space telescope

1

An article published in “The Astrophysical Journal Letters” reports the discovery of two exoplanets in the orange star HD 21749’s system, one of which is the first Earth-sized identified thanks to NASA’s TESS space telescope and the other a Mini-Neptune. A team of researchers led by Diana Dragomir already submitted a first version of the article on the exoplanet HD 21749b, the Mini-Neptune also referred to as TOI 186.01, mentioning as candidate TOI 186.02 the rocky exoplanet now referred to as HD 21749c in the new version of the article in which it’s considered confirmed.

Artist's concept of a planetesimal orbiting the white dwarf SDSS J122859.93+104032.9 (Image courtesy University of Warwick/Mark Garlick)

0

An article published in the journal “Science” reports the discovery of what’s probably a fragment of a planet that orbits a white dwarf. A team of researchers led by the British University of Warwick used the Gran Telescopio Canarias of La Palma to study the debris disk that surrounds the white dwarf cataloged as SDSS J122859.93+104032.9 detecting anomalies in the emission lines that have been interpreted as the result of the presence of what has been called a planetesimal orbiting the star in about two hours.