News by Subject Space & Planetary

Among the methods astronomers have found to measure the expansion rate of the local universe, the Hubble constant, surface brightness fluctuations is potentially one of the most precise. Scientists have now published the first good SBF estimate of the Hubble constant, pegging it at 73.3 km/s/Mpc: in the ballpark of other measurements of the local expansion, including the gold standard using Type Ia supernovae. The new estimate highlights the mismatch with estimates from the early universe.

A rocky planet discovered in the Virgo constellation could change how we look for life in the universe.

During the past 25 years astronomers have discovered a wide variety of exoplanets, made of rock, ice and gas, thanks to the construction of astronomical instruments designed specifically for planet searches. Also, using a combination of different observing techniques they have been able to determine a large numher of masses, sizes, and hence densities of the planets, which helps them to estimate their internal composition and raising the number of planets which have been discovered outside the Solar System.

In the new study, published in Science Advances, researchers analysed the composition of solar energetic particles heading towards Earth, and found they had the same "fingerprint" as plasma located low in the Sun's corona, close to the middle region of the Sun's atmosphere, the chromosphere.

About 17 years ago, J. Martin Laming, an astrophysicist at the US Naval Research Laboratory, theorized why the chemical composition of the Sun's tenuous outermost layer differs from that lower down. His theory has recently been validated by combined observations of the Sun's magnetic waves from the Earth and from space.

An international team led by Prof. dr habil. Andrzej Niedzielski, an astronomer from the Nicolaus Copernicus University in Torun (Poland), has discovered yet another three extrasolar planets. These planets revolve around the stars that can be called elder sisters of our Sun.

Red supergiants are a class of star that end their lives in supernova explosions. Their lifecycles are not fully understood, partly due to difficulties in measuring their temperatures. For the first time, astronomers develop an accurate method to determine the surface temperatures of red supergiants.

A team of international researchers went back to the formation of the solar system 4.6 billion years ago to gain new insights into the cosmic origin of the heaviest elements on the periodic table.