Stars

Blogs about stars

An artistic representation of a tidal disruption event: a star is destroyed by the intense tidal forces of a supermassive black hole, while some of its material forms an accretion disk around it. (Image generated by Google Gemini)

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An article published in the journal “Nature Astronomy” reports the results of a study on the formation of jets of materials by black holes, identifying a rule that appears to be independent of their mass. Adelle Goodwin of the Curtin University’s International Centre for Radio Astronomy Research, Australia, and Andrew Mummery of Princeton’s Institute for Advanced Study, USA, studied a series of tidal disruption events in which black holes destroyed a star. By analyzing the collected data, the researchers concluded that all black holes emit powerful jets of material at the same stage of their accretion cycle, a stage linked solely to the rate at which the black hole feeds, rather than its mass.

Betelgeuse as seen by the ALMA radio telescope (Image ALMA(ESO/NAOJ/NRAO)/W. Dent et al.)

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An article accepted for publication in the journal “Astronomy & Astrophysics” reports the results of observations of structures that are lasting longer than predicted in the atmosphere of the star Betelgeuse. A team of researchers used the ALMA radio telescope to obtain some of the most detailed views of Betelgeuse’s surface ever obtained. This allowed them to study its really uneven surface and the structures within its atmosphere.

Some of the galaxies included in the DESI Legacy Imaging Surveys map (Image: DESI Legacy Imaging Surveys/LBNL/DOE & KPNO/CTIO/NOIRLab/NSF/AURA)

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The DESI Legacy Imaging Surveys team has released the largest 2D map of the universe. Consisting of 5.6 trillion pixels, this map includes nearly 4 billion celestial objects, ranging from asteroids to galaxies, as well as other objects such as stars, black holes, and more. It’s a vast archive spanning approximately three-quarters of the sky, useful for astronomical studies requiring information at optical and near-infrared frequencies. This result isn’t the final one, as the map will be used to determine the distances to objects such as quasars to construct a new map, this time 3D.

From right: Orion, Betelgeuse, and a detail of the star candidate Betelgeuse B (Image ESO/M. Montargès et al. Background: N. Rissinger (skysurvey.org))

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An article published in the journal “Astronomy & Astrophysics” offers the best evidence yet for the existence of a companion to the star Betelgeuse. A team of researchers led by Miguel Montargès of the Paris Observatory – PSL used the SPHERE instrument, and specifically its ZIMPOL polarimeter, mounted on the VLT in Chile to capture a direct image of what appears to be a star close to Betelgeuse. Independent observations will be needed to confirm the existence of the candidate Betelgeuse B. This study suggests it’s a star with a mass between 2.6 and 3.1 times the Sun’s.

The Sextans A galaxy. In the inset, in green, polycyclic aromatic hydrocarbons (Image NASA, ESA, CSA, Elizabeth Tarantino (STScI), Martha Boyer (STScI), Julia Roman-Duval (STScI); Image Processing: Alyssa Pagan (STScI))

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An article published in “The Astrophysical Journal” reports the results of a study of dust generated by red giant stars towards the end of their lives under conditions similar to those existing in the first galaxies of the universe. A team of researchers led by Claudio Gavetti of the Italian National Institute for Astrophysics and the University of Roma Tre used observations conducted with the James Webb Space Telescope to study the Sextans A dwarf galaxy, where the environment is very metal-poor. Observations of a quality unimaginable in the past allowed to understand how these stars produce cosmic dust in environments similar to those of the early universe.