Stars

Artist's concept of WD1054-226's system (Image courtesy Mark A. Garlick / markgarlick.com)

An article published in the journal “Monthly Notice of the Royal Astronomical Society” reports the observation of debris orbiting the white dwarf cataloged as WD1054-226 in a formation that suggests a gravitational bond such as the one which can be generated by a planet. A team of researchers used the ULTRACAM camera mounted on ESO’s NTT telescope at La Silla Observatory in Chile to examine objects that regularly pass in front of those star remnants. Data obtained from NASA’s TESS space telescope helped identify what appears to be a disk of debris that hasn’t dispersed, perhaps thanks to a planet acting as a sort of shepherd that keeps them bound. The planet would be in ​​that system’s habitable area, a special case since it has a white dwarf at its center.

Artist’s impression of Proxima d and Proxima Centauri (Image ESO/L. Calçada)

An article published in the journal “Astronomy & Astrophysics” reports the discovery of another rocky planet in the Proxima Centauri system. A team of researchers led by João Faria of the Instituto de Astrofísica e Ciências do Espaço, Portugal, used detections conducted with the ESPRESSO spectrograph mounted on ESO’s VLT in Chile to find the traces of the planet that was cataloged as Proxima d. This is the exoplanet with the smallest mass identified with the radial velocity method since the estimated minimum mass is about a quarter of the Earth’s, twice Mars’s. Its distance from Proxima Centauri is around 4 million kilometers, so it’s more similar to Venus or Mercury.

The globular cluster M14 (Image NOIRLab/NSF/AURA)

An article published in “The Astrophysical Journal” reports the results of observations of the globular cluster M14. A team of astronomers led by Francesca D’Antona of the Italian National Institute of Astrophysics, Rome, used the Hubble Space Telescope to study M14, discovering that over a third of the stars in M14 contains an amount of helium never observed outside globular clusters, as it has peaks higher than 30% of their mass. According to the researchers, the most likely explanation is that these are second-generation stars that swallowed the helium ejected by first-generation stars during their agony.

Artist's concept of the exoplanet TOI 560.01 with its star (Image Adam Makarenko (Keck Observatory))

Two articles published in “The Astronomical Journal” report studies on as many exoplanets of the mini-Neptune type that are losing their atmosphere. Two teams led by Michael Zhang with other members in common used the Hubble Space Telescope to study the exoplanet HD 63433c and the Keck Observatory in Hawaii to study the exoplanet TOI 560.01, also known as HD 73583b. In both cases, the XMM-Newton space telescope was used to study the high-energy emissions from their stars and from the outflow of gas from their atmospheres. Observations of gas leaking into space is a confirmation of the theory that mini-Neptunes can transform into super-Earths at the end of that loss.

The Andromeda galaxy (M31) with the cluster B023-G078

An article published in “The Astrophysical Journal” reports the discovery of a rare intermediate-mass black hole in the Andromeda galaxy at the center of what could be a stripped nucleus, what remains of a galaxy swallowed by Andromeda. A team of researchers observed the star cluster cataloged as B023-G078 at the Gemini Observatory and with the Hubble Space Telescope to calculate the mass distribution within it, a crucial step to understand its nature as a stripped nucleus and identify the intermediate-mass black hole. This could be a way to discover this rare type of black hole, which some models claim merges with others to form supermassive black holes following galaxy mergers.