Astronomy / Astrophysics

Blogs about Astronomy and Astrophysics

The galaxy NGC 1386

An article published in the journal “Monthly Notices of the Royal Astronomical Society” reports a study of the galaxy NGC 1386 that shows that star formation processes are taking place in its central regions despite the fact that it contains mostly old stars. A team of researchers led by astronomer Almudena Prieto of the Instituto de Astrofísica de Canarias in Spain combined observations conducted in visible light and near-infrared with ESO’s VST and in radio waves with the ALMA radio telescope to study those processes that are bringing about a sort of rejuvenation within NGC 1386.

The star cluster NGC 602 (Image ESA/Webb, NASA & CSA, P. Zeidler, E. Sabbi, A. Nota, M. Zamani (ESA/Webb))

An article published in “The Astrophysical Journal” reports the identification of 64 brown dwarf candidates in the star cluster NGC 602 in the Small Magellanic Cloud, one of the Milky Way’s satellite galaxies. A team of researchers used the James Webb Space Telescope to obtain the sensitivity and resolution needed to detect possible objects halfway between the planet and the star about 200,000 light-years away. Follow-up studies are needed to verify these candidates, the first brown dwarfs to be verified outside the Milky Way. NGC 602 is poor in elements heavier than hydrogen and helium, a condition that was normal when the universe was young, further reason for interest in studying the processes within the cluster.

Illustration of a black hole and the region surrounding it with the corona bright at X-rays (Image NASA/Caltech-IPAC/Robert Hurt)

An article published in “The Astrophysical Journal Letters” reports the results of a study on the region of very hot plasma that surrounds a black hole called the corona. A group of researchers used detections conducted with the IXPE space telescope to obtain precise information on the corona of 12 black holes ranging from stellar-mass ones to supermassive black holes. For the first time, it was possible to observe the geometry of the corona of black holes and its relationship with the accretion disk that surrounds them. The geometry seems very similar regardless of the size of the black holes but this is still a tentative result.

Artist's illustration of Gliese 229 Ba and Gliese 229 Bb with Gliese 229 A (Image courtesy K. Miller, R. Hurt (Caltech/IPAC))

Two articles, one published in the journal “Nature” and one in “The Astrophysical Journal Letters”, report the results of two independent studies on Gliese 229 B, the first brown dwarf whose existence was confirmed, which conclude that it’s actually a pair of close brown dwarfs. A team led by Caltech researcher Jerry Xuan used the GRAVITY and CRIRES+ instruments mounted on ESO’s VLT in Chile while a team led by Sam Whitebook, also from Caltech, and Tim Brandt of the Space Telescope Science Institute in Baltimore, used the NIRSPEC instrument installed at the Keck Observatory in Hawaii. There were already suspicions about the nature of Gliese 229 B due to some inconsistencies detected in its characteristics but only now was it possible to find the evidence.

R Aquarii (NASA, ESA, M. Stute, M. Karovska, D. de Martin & M. Zamani (ESA/Hubble))

An image captured by the Hubble Space Telescope depicts R Aquarii, a binary system consisting of a red giant and a white dwarf. Four different filters of the WFC3 (Wide Field Camera 3) instrument were used in visible light to create the most recent observation of R Aquarii conducted with Hubble. This allowed to examine the changes that have occurred in particular in the nebula surrounding the pair.

The R Aquarii system is in the cosmic neighborhood, being about 650 light-years from Earth. For this reason, it has been the subject of study with different instruments since the two stars that make up the pair, which are invisible to the naked eye, were discovered. For example, it was the subject of a test using a subsystem of the SPHERE instrument installed on ESO’s VLT in Chile.