Telescopes

Artistic concept of a red dwarf in a phase of flares that strip the atmosphere from one of its planets (Image NASA, ESA, and D. Player (STScI))

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An article accepted for publication in “The Astrophysical Journal” reports the results of spectroscopic observations of the activity of the star TRAPPIST-1 conducted with the James Webb Space Telescope. A team of researchers observed four flares of this ultra-cool dwarf, which occurred over the course of about 27 hours. By adding data obtained with other instruments, it was possible to develop a mathematical method to separate the light of those flares from normal stellar radiation. In the study of a very small but also active star, this is very useful to improve the quality of observations of the seven rocky planets of the TRAPPIST-1 system.

AT2023fhn as seen by Hubble

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An article being published in the journal “Monthly Notices of the Royal Astronomical Society” reports the observation of a Luminous Fast Blue Optical Transient (LFBOT), a rare type of cosmic explosion of still uncertain nature which was cataloged as AT2023fhn. A team of researchers used various telescopes to try to study one of the few phenomena of this type known so far but this brought more questions than answers because its origin was found far from any galaxy.

The G35.2-0.7N region (Image ESA/Hubble & NASA, R. Fedriani, J. Tan)

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An image captured by the Hubble Space Telescope depicts the star-forming region cataloged as G35.2-0.7N, in which massive stars form. Protostars are surrounded by cocoons of gas and dust which in turn are inside larger clouds, and that usually makes them invisible. However, one of those protostars near the center of the image is emitting jets of materials that illuminate the region and dig into the gas, allowing some of the protostellar light to escape.

About 7,200 light-years away from Earth, the G35.2-0.7N region is of interest to astronomers who are studying the processes that lead to the birth of stars. The Hubble Space Telescope’s Wide Field Camera 3 (WFC3) instrument is one of many that have been used over time in various studies taking photos that have now been assembled into a single image.

An image of the Pinwheel Galaxy with the location of supernova 2023ixf captured on June 27, 2023, using various optical and infrared frequency filters

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Two articles published in “The Astrophysical Journal Letters” report as many studies on the supernova cataloged as SN 2023ixf. Two teams of researchers with members in common examined the evolution of this supernova discovered in the so-called Pinwheel Galaxy. To do this, they used various instruments including some from the Center for Astrophysics (CFA) Harvard & Smithsonian which allowed observations in different electromagnetic bands. The results were different from what was expected from the explosion of a massive star with a delay in the time of the peak of the light pulse just before the explosion. The conclusion is that this was due to the presence of dense materials ejected from the star in the year preceding the supernova.

Artist's illustration of the exoplanet Tahay / GJ 367 b (Image NASA)

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An article published in “The Astrophysical Journal Letters” reports a study on the exoplanet GJ 367 b, or Gliese 367 b, formally known by the name Tahay, which concludes that its core is composed almost entirely of iron for a density that is almost twice the Earth’s. The researchers also announced the discovery of two more planets in the system of the star GJ 367, formally known as Añañuca, which may be super-Earths.

Just over 30 light-years from Earth, Añañuca is a red dwarf with a mass and size just under half of the Sun’s. Observations began in 2019 with NASA’s TESS space telescope and in 2021 the data collected led to the exploration of the possibility that a planet orbited very close to this star, subsequently confirmed with other instruments. Tahay’s roughly 7.7-hour year is the shortest in the cosmic neighborhood, one reason for interest and worthy of its own name.