Category Astronomy/Space

Planetary disk around the star known as TW Hydrae. Credit: S. Andrews (Harvard-Smithsonian CfA); B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO)

The dusty disk surrounding star TW Hydrae exhibits circular features that may signal the formation of protoplanets. An astrophysicist argues, however, that the innermost actually points to the impending dispersal of the disk. When the maps appeared at the end of March, experts were electrified. The images revealed an orange-red disk pitted with circular gaps: a detailed portrait of a protoplanetary disk, made up of gas and dust grains, associated with a young star – the kind of structure out of which planets could be expected to form...

Hubble Space Telescope image of supernova 1994D in galaxy NGC 4526 © NASA/ESA

A new math model details a way that dead stars called white dwarfs could detonate, producing a type of explosion that is instrumental to measuring the extreme distances in our universe. The mechanism, described in the Monthly Notices of the Royal Astronomical Society, could improve our understanding of how Type Ia supernovae form. “Type Ia supernovae are extremely important objects in physics, best known for their role in revealing that the expansion of the universe is accelerating,” said Prof. Saavik Ford. “The problem is that people do not agree on exactly how Type Ia supernovae come to be.”

Current research indicates that Type Ia supernova explosions originate from binary star systems – two stars orbiting one...

(a) The trajectory of the electron #1 in the 3D velocity space. (b) A conceptual model of the noncrossing electron orbits. A noncrossing Speiser orbit (solid line) and a noncrossing regular orbit (red). They are computed in a configuration similar to the traditional Speiser orbit (dashed line) in Figure 1. (c) The velocity-space trajectory of the noncrossing Speiser orbit for y < 0 and z < 1.5.

Phenomena like solar flares and auroras are consequences of magnetic reconnection in the near-Earth space. These “magnetic reconnection” events are akin to magnetic explosions that accelerate particles as they rapidly change the topology of the magnetic field lines...

This artist’s conception shows a star behind a shattered comet. One of the theories for KIC 8462852’s unusual dimming is the presence of debris from a collision or breakup of a planet or comet in the star’s system, creating a short-term cloud that blocks some starlight. Credit: Image is courtesy of NASA/JPL-Caltech

Star KIC 8462852 in constellation Cygnus has been raising eyebrows both in and outside of the scientific community for the past year. In 2015 a team of astronomers announced that the star underwent a series of very brief, non-periodic dimming events while it was being monitored by NASA’s Kepler space telescope, and no one could quite figure out what caused them. A new study from Carnegie’s Josh Simon and Caltech’s Ben Montet has deepened the mystery...