Astronomers have detected what may be the most-rapidly-rotating, ultra-cool, brown-dwarf star ever seen. The super-fast rotation period of less than an hour was measured by using the 305-metre Arecibo radio telescope — the same telescope that was used to discover the first planets ever found outside our solar system.
A computer simulation of the powerful jets generated by supermassive black holes at the centres of the largest galaxies explains why some burst forth as bright beacons visible across the universe, while others fall apart and never pierce the halo of the galaxy. A jet’s hot ionised gas is propelled by the twisting magnetic fields of the central rotating black hole.
Like sending sensors up into a hurricane, NASA has flown four spacecraft through an invisible maelstrom in space, called magnetic reconnection. Magnetic reconnection is one of the prime drivers of space radiation and so it is a key factor in the quest to learn more about our space environment and protect our spacecraft and astronauts as we explore farther and farther from our home planet.
A detailed study of young stars and their surroundings has produced dramatic new evidence about how multiple-star systems form and how the dusty discs that are the raw material for planets grow around young stars. Scientists used the Very Large Array (VLA) radio telescope to study nearly 100 newborn stars in a cloud of gas and dust about 750 light-years from Earth.
New information about the way mature stars spin indicates that one recently developed method for determining a star’s age needs to be recalibrated for stars that are older than our Sun, as spin rate is one of the few windows into stellar ages. This has implications for our own solar system, as our own Sun might be on the cusp of a transition in its magnetic field.
Supermassive black holes at the centres of galaxies can spawn tremendous bipolar jets extending over hundreds of thousands of light-years. A CfA study of the bright radio jet galaxy Pictoris suggests that bright X-ray emission from the jets is produced by rapidly moving charged particles in magnetic fields.
Astronomers have for the first time probed the magnetic fields in the mysterious inner regions of stars, finding they are strongly magnetised. Using a technique called asteroseismology, the scientists were able to calculate the magnetic field strengths in the fusion-powered hearts of dozens of red giants, stars that are evolved versions of our Sun.