Category Astronomy/Space

The star HD 65907 is not what it appears to be. It’s a star that looks young, but on closer inspection, it is actually much, much older. What’s going on? Research suggests that it is a resurrected star.

Astronomers employ different methods to measure a star’s age. One is based on its brightness and temperature. All stars follow a particular path in life, known as the main sequence. The moment they begin fusing hydrogen in their cores, they maintain a strict relationship between their brightness and temperature. By measuring these two properties, astronomers can roughly pin down the age of a star.

But there are other techniques, like measuring the amount of heavy elements in a stellar atmosphere...

An international team of astronomers, led by researchers from the Astronomical Observatory of the University of Warsaw, have identified a new class of cosmic X-ray sources. The findings have been published in The Astrophysical Journal Letters.

Most people encounter X-rays during medical visits where they are used to create images of bones or diagnose lung conditions. These X-rays are generated using artificial sources.

However, not everyone knows that celestial objects can also emit X-ray radiation. “Some cosmic phenomena produce X-rays naturally,” explains Dr. Przemek Mróz, the lead author of the study. “For example, X-rays may be produced by a hot gas falling onto compact objects like white dwarfs, neutron stars, or black holes...

An international team of researchers has detected a binary star orbiting close to Sagittarius A*, the supermassive black hole at the center of our galaxy. It is the first time a stellar pair has been found in the vicinity of a supermassive black hole.

The discovery, based on data collected by the European Southern Observatory’s Very Large Telescope (ESO’s VLT), helps us understand how stars survive in environments with extreme gravity, and could pave the way for the detection of planets close to Sagittarius A*.

“Black holes are not as destructive as we thought,” says Florian Peißker, a researcher at the University of Cologne, Germany, and lead author of the study published in Nature Communications.

Binary stars, pairs of stars orbiting each other, are very common in the univ...

New observations reveal the challenges of detecting planetary atmospheres

Recent measurements with the James Webb Space Telescope (JWST) cast doubt on the current understanding of the exoplanet Trappist-1 b’s nature. Until now, it was assumed to be a dark rocky planet without an atmosphere, shaped by a billion-year-long cosmic impact of radiation and meteorites. The opposite appears to be true. The surface shows no signs of weathering, which could indicate geological activity such as volcanism and plate tectonics. Alternatively, a planet with a hazy atmosphere composed of carbon dioxide is also viable. The results demonstrate the challenges of determining the properties of exoplanets with thin atmospheres.

Trappist-1 b is one of seven rocky planets orbiting the star Trappist-1, ...