Astronomers using NASA’s Hubble Space Telescope and ESO’s Very Large Telescope in Chile have discovered never-before-seen moving features within the dusty disc surrounding the young, nearby star AU Microscopii. The fast-moving, wave-like structures are moving at 22,000 miles per hour — fast enough to escape the star’s gravitational pull.
On 6 October 1995, astronomers started a revolution with the discovery of 51 Pegasi b — the first planet found orbiting a Sun-like star beyond our solar system. As we celebrate the 20th anniversary of that momentous discovery, the current total of known exoplanets stands at 5,596. More than 1,000 of these were discovered by NASA’s Kepler mission.
Astronomers have long turned their telescopes to the wide swaths of interstellar medium to get a look at the formation and birth of stars. A team of international researchers has just released the most comprehensive images anyone has ever seen of the Milky Way’s cold interstellar gas clouds where new stars and solar systems are being born.
Until now, scientists have determined the mass of stars, planets and moons by studying their motion in relation to others nearby, using the gravitational pull between the two as the basis for their calculations. However, in the case of young pulsars, mathematicians at the University of Southampton have now found a new way to measure their mass — even if a star exists on its own in space.
Since its arrival at comet 67P/Churyumov-Gerasimenko in August 2014, ESA’s Rosetta spacecraft has been surveying the surface and the environment of this curiously shaped body. Now that the comet is experiencing a brief, hot southern hemisphere summer, its south polar regions have emerged from almost five years of total darkness and it has been possible to observe them with other Rosetta instruments.
When a massive star ends its life in a spectacular supernova explosion, it can leave behind a rapidly spinning neutron star with a period of 1-10 milliseconds. Such objects that emit electromagnetic radiation in a lighthouse-like beam sweeping past the Earth are known as millisecond pulsars. CfA astronomers have identified white dwarf companions of two more millisecond pulsars in the spectacular globular cluster 47 Tucanae.
Water reserves found on the Moon are the result of asteroids acting as “delivery vehicles” and not of falling comets as was previously thought. Using computer simulation, scientists from the Moscow Institute of Physics and Technology and the RAS Geosphere Dynamics Institute have discovered that a large asteroid can deliver more water to the lunar surface than the cumulative fall of comets over a billion year period.
When a star collapses forming a black hole, a space-time singularity is created wherein the laws of physics no longer work. In 1965, Sir Roger Penrose presented a theorem where he associated that singularity with so-called ”trapped surfaces” that shrink over time. That hypothesis — one of the results of the general theory of relativity — is now celebrating its 50th anniversary.
At half the diameter of Pluto, Charon is the largest satellite relative to its planet in the solar system. NASA’s New Horizons spacecraft has returned the best colour and the highest resolution images yet of Charon, showing a landscape covered with mountains, canyons, landslides, surface-colour variations and more — all evidence of a surprisingly complex and violent history.
Galaxy clusters are often described by superlatives. After all, they are huge conglomerations of galaxies, hot gas, and dark matter, representing the largest structures in the universe held together by gravity. New observations of the galaxy cluster SPT-CLJ2344-4243 (or Phoenix Cluster) at X-ray, ultraviolet, and optical wavelengths are helping astronomers better understand this extraordinary system.
© 2019 Pole Star Publications Limited