How a lack of activity on the Sun might affect our planet

At 10:00 GMT on Monday, the most important alarm clock in the Solar System will wake up ESA's sleeping Rosetta spacecraft.

NASA is inviting people around the world to submit their names to be etched on a microchip aboard a spacecraft headed to the asteroid Bennu in 2016.

Temples in the ill-fated Roman port seem to be aligned with stars important in Greek and Egyptian mythology, suggesting Pompeii was a cultural melting pot
    

Astronomers have used ESO's HARPS planet hunter in Chile, along with other telescopes around the world, to discover three planets orbiting stars in the cluster Messier 67. Although more than one thousand planets outside the Solar System are now confirmed, only a handful have been found in star clusters. Remarkably one of these new exoplanets is orbiting a star that is a rare solar twin — a star that is almost identical to the Sun in all respects.

Comet craft ready to wake

Nature 505, 7483 (2014). http://www.nature.com/doifinder/10.1038/505269a

Author: Elizabeth Gibney

Stakes high as European Space Agency waits for Rosetta orbiter to come out of hibernation.

Astrophysics: The heart of darkness

Nature 505, 7483 (2014). http://www.nature.com/doifinder/10.1038/505280a

Author: Ron Cowen

The supermassive black holes that lie at the centre of every large galaxy are full of mysteries. But astronomers are finally getting a clear look.

Astronomy: The great unseen

Nature 505, 7483 (2014). doi:10.1038/505290a

Author: Eric Hand

Eric Hand views a planetarium show on dark matter and dark energy that is both dislocating and transfixing.

Astrophysics: Black hole found orbiting a fast rotator

Nature 505, 7483 (2014). doi:10.1038/505296a

Authors: M. Virginia McSwain

Stars of spectral type 'Be' are often found with neutron stars or other evolved analogues, but a black-hole companion has never been spotted before. Optical emission from a black hole's surroundings has given it away. See Letter p.378

A Be-type star with a black-hole companion

Nature 505, 7483 (2014). doi:10.1038/nature12916

Authors: J. Casares, I. Negueruela, M. Ribó, I. Ribas, J. M. Paredes, A. Herrero & S. Simón-Díaz

Stellar-mass black holes have all been discovered through X-ray emission, which arises from the accretion of gas from their binary companions (this gas is either stripped from low-mass stars or supplied as winds from massive ones). Binary evolution models also predict the existence of black holes accreting from the equatorial envelope of rapidly spinning Be-type stars (stars of the Be type are hot blue irregular variables showing characteristic spectral emission lines of hydrogen). Of the approximately 80 Be X-ray binaries known in the Galaxy, however, only pulsating neutron stars have been found as companions. A black hole was formally allowed as a solution for the companion to the Be star MWC 656 (ref. 5; also known as HD 215227), although that conclusion was based on a single radial velocity curve of the Be star, a mistaken spectral classification and rough estimates of the inclination angle. Here we report observations of an accretion disk line mirroring the orbit of MWC 656. This, together with an improved radial velocity curve of the Be star through fitting sharp Fe ii profiles from the equatorial disk, and a refined Be classification (to that of a B1.5–B2 III star), indicates that a black hole of 3.8 to 6.9 solar masses orbits MWC 656, the candidate counterpart of the γ-ray source AGL J2241+4454 (refs 5, 6). The black hole is X-ray quiescent and fed by a radiatively inefficient accretion flow giving a luminosity less than 1.6 × 10−7 times the Eddington luminosity. This implies that Be binaries with black-hole companions are difficult to detect in conventional X-ray surveys.

Eight years after it left Earth, NASA's New Horizons spacecraft is approaching Pluto. The encounter begins less than a year from now.

From cleanroom to liftoff, watch an incredible time-lapse movie of Gaia's final preparations on Earth before shooting for the stars.

 

 

 

Half of the sun-like stars in the galaxy are in binary pairs – we've just glimpsed into a stellar nursery to see how such pairs come into the universe
    

Kepler clue to supernova puzzle

Nature 505, 7483 (2014). http://www.nature.com/doifinder/10.1038/505274a

Author: Ron Cowen

Two white dwarfs favoured as precursors of type Ia supernovae.