Hip 21152B, brunette in Hyades

Hip 21152B, brunette in Hyades


Images of the brown dwarf Hip 21152 B obtained through direct imaging with the Subaru and Keck II telescopes. The host star of the binary system, Hip 21152, is shown by the yellow star. The brown mate from the circle. Credits: M. Kuzuhara et al./WM Keck Observatory/Subaru Telescope

The Hyadi is a group of young stars located about 150 light years from us Taurus star. to createclear pole closest to Earth and one of the most studied constellations by astronomers. Among the hundreds of stars that are part of the group is Hip 21152, a Sun-like star about 750 million years old, discovered in satellite data. Gaia And Hipparchus.

Using tools Scexao (Subaru Coronagraphic Extreme Adaptive Optics) e Charis (Coronagraphic High Angular Resolution Imaging Spectrograph) is installed on the Japanese telescope. Subaru and the instrument Nirc2 (Near-Infrared Camera) is installed on the telescope Hawaiian Cake II, Masayuki Kuzuhara – researcher at Astronomy Center of National Institutions of natural science (Nins) – and his team has revealed a companion next to this star. His name is Kiboko 21152B and is the first confirmed minor star companion for the star main chain discovery through direct visualization inside the cluster.

Hip 21152 is one a brown dwarf, a celestial object too large to be considered a planet and too small to be a true star; their mass is actually insufficient to initiate nuclear fusion, which is why they are often called “failed stars”.

The team discovered it in four direct images obtained from October 2020 to October 2021 by the two telescopes. Combining these observations with data on radial velocity of the star found by the instrument hides placed on top 188 cm Okayama Reflecting Telescopeand data is enabled own pace obtained from the Gaia and Hipparcos satellites, the researchers determined the star’s orbit. From these orbital data, using Kepler’s laws, they then found the mass: between 22 and 36 of Jupiter.

The team also found a fascinating profile of Hip 21152B, which shows how the star’s sky is changing from a brown dwarf to a “type L” to one oftype T“, which means that the star is cooling. According to the researchers’ estimates, its temperature would be between 926 and 1026 degrees Celsius.

A group of researchers led by Masayuki Kuzuhara is not the only one who discovered this “failed star”. Far from Kyle Franson and his colleagues (OK, 2023), Hip 21152B has been discovered independently and led by a team Mariangela Bonavita of Inaf – Astronomical Observatory of Padua, which saw him in the photo acquired by the Spectro-Polarimetric High-contrast Exoplanet Survey instrument (sphere) of Very large telescope of ESO in the context of the Copains Pilot Study (Mr2022)

“These results may provide an important clue to understanding the atmospheres of giant planets and brown dwarfs in terms of how and when they exhibit atmospheric properties similar to those seen in the systems Hip 21152B and HR 8799” he says Masayuki Kuzuhara, a researcher at the Astronomy Center and lead author of the study. “We expect Hip 21152B to play an important role as a benchmark for future advances in astronomy and planetary science.”

To know more:

  • Read on Astrophysical Journal Letters article”Live Imaging and Variable Mass Detection of a Companion Star Orbiting the Sun-like Accelerating Hyades by SCExAO/CHARIS*by Masayuki Kuzuhara, Thayne Currie, Takuya Takarada, Timothy D. Brandt, Bun’ei Sato, Taichi Uyama, Markus Janson, Jeffrey Chilcote, Taylor Tobin, Kellen Lawson, Yasunori Hori, Olivier Guyon, Tyler D. Groff, Julien Lozi, Sebastien , Sebastien Vievard, Ananya Sahoo, Vincent Deo, Nemanja Jovanovic, Kyohoon Ahn, Frantz Martinache, Nour Skaf, Eiji Akiyama, Barnaby R. Norris, Mickaël Bonnefoy, Krzysztof G. Hełminiak, Tomoyuki Kudo, Michael W. McElwain, Matthias Samland, Kevin Samland, Matthias Samland John Wisniewski, Gillian R. Knapp, Jungmi Kwon, Jun Nishikawa, Eugene Serabyn, Masahiko Hayashi and Motohide Tamura