Since astronomers captured the bright explosion of a star on February 24, 1987, researchers have been searching for the squashed stellar core that should have been left behind. A group of astronomers using data from NASA space missions and ground-based telescopes may have finally found it.
To come into being, galaxies need a steady diet of cold gases to undergo gravitational collapse. The larger the galaxy, the more cold gas it needs to coalesce and to grow.
Massive galaxies found in the early universe needed a lot of cold gas--a store totaling as much as 100 billion times the mass of our sun.
But where did these early, super-sized galaxies get that much cold gas when they were hemmed in by hotter surroundings?
A new theoretical study has proposed a novel mechanism for the creation of supermassive black holes from dark matter. The international team find that rather than the conventional formation scenarios involving 'normal' matter, supermassive black holes could instead form directly from dark matter in high density regions in the centres of galaxies. The result has key implications for cosmology in the early Universe, and is published in Monthly Notices of the Royal Astronomical Society.
For only the second time, astronomers have linked an elusive particle called a high-energy neutrino to an object outside our galaxy. Using ground- and space-based facilities, including NASA's Neil Gehrels Swift Observatory, they traced the neutrino to a black hole tearing apart a star, a rare cataclysmic occurrence called a tidal disruption event.
Large galaxies are known to strip the gas that occupies the space between the stars of smaller satellite galaxies.
In research published today, astronomers have discovered that these small satellite galaxies also contain less 'molecular' gas at their centres.
Molecular gas is found in giant clouds in the centres of galaxies and is the building material for new stars. Large galaxies are therefore stealing the material that their smaller counterparts need to form new stars.
EUGENE, Ore. -- Feb. 19, 2021 -- Friction caused by dry Martian dust particles making contact with each other may produce electrical discharge at the surface and in the planet's atmosphere, according University of Oregon researchers.
However, such sparks are likely to be small and pose little danger to future robotic or human missions to the red planet, they report in a paper published online and scheduled to appear in the March 15 print issue of the journal Icarus.
Cooperative operations between a solar observation satellite and a sounding-rocket telescope have measured the magnetic field strength in the photosphere and chromosphere above an active solar plage region. This is the first time that the magnetic field in the chromosphere has been charted all the way up to its top. This finding brings us closer to understanding how energy is transferred between layers of the Sun.
The latest observations from Insight-HXMT were published online in Nature Astronomy on Feb. 18. Insight-HXMT has discovered the very first X-ray burst associated with a fast radio burst (FRB) and has identified that it originated from soft-gamma repeater (SGR) J1935+2154, which is a magnetar in our Milky Way.
Every day space telescopes provide spectacular images of the solar activity. However, their instruments are blind to its main driver: the magnetic field in the outer layers of the solar atmosphere, where the explosive events that occasionally affect the Earth occur. The extraordinary observations of the polarization of the Sun's ultraviolet light achieved by the CLASP2 mission have made it possible to map the magnetic field throughout the entire solar atmosphere, from the photosphere until the base of the extremely hot corona.
Cygnus X-1, a binary star system first discovered in 1964, comprises one of the closest black holes to Earth. New observations of this black hole, the first ever detected, have led astronomers to question what they know about the Universe's most mysterious objects.
An international team, including researchers from the National Astronomical Observatories of the Chinese Academy of Sciences (NAOC), recently found that the stellar-mass black hole in the Cygnus X-1 binary system has a mass 21 times the mass of the Sun and rotates at a speed close to the speed of light.
In the search for planets capable of sustaining life, an international research team with members from ETH has taken a significant step forward. As the researchers reported recently in the journal Nature Communications, they found signs of a Neptune-sized planet in the Alpha Centauri star system, a mere 4.4 light years away from Earth. This exoplanet is located in a zone that may offer suitable conditions for life. The team was able to collect data with unprecedented sensitivity, thus registering even very weak signals.
Earth is a disruptive factor
Gravity might play a bigger role in the formation of elementary particles than scientists used to believe. A team of physicists from RUDN University obtained some solutions of semi-classical models that describe particle-like waves. They also calculated the ratio between the gravitational interaction of particles and the interaction of their charges. The results of the study were published in the Universe journal.
Astronomers have tested a method for reconstructing the state of the early Universe by applying it to 4000 simulated universes using the ATERUI II supercomputer at the National Astronomical Observatory of Japan (NAOJ). They found that together with new observations the method can set better constraints on inflation, one of the most enigmatic events in the history of the Universe. The method can shorten the observation time required to distinguish between various inflation theories.
Both Earth and Mars currently have oxidising atmospheres, which is why iron-rich materials in daily life develop rust (a common name for iron oxide) during the oxidation reaction of iron and oxygen. The Earth has had an oxidising atmosphere for approximately two and a half billion years, but before that, the atmosphere of this planet was reducing - there was no rust.
Astronomers found something they weren't expecting at the heart of the globular cluster NGC 6397: a concentration of smaller black holes lurking there instead of one massive black hole.