Astronomy Now – Page 168

Spectacular green fireball seen over UK

17 March 2016 Astronomy Now

Observers across the British Isles report a fireball seen shortly before 3:17am GMT on 17 March. The UK Meteor Observation Network’s monochrome camera in Church Crookham, Hampshire also recorded the spectacular event, which lasted for several seconds and was seen for hundreds of miles.

Students map Milky Way with dwarf stars

17 March 2016 Astronomy Now

Two astronomy students from Leiden University have mapped the entire Milky Way Galaxy in dwarf stars for the first time. They show that there are a total of 58 billion dwarf stars, of which seven percent reside in the outer regions of our galaxy. This result is the most comprehensive model ever for the distribution of these stars.

Sun-like star shows magnetic field was critical for life on early Earth

16 March 2016 Astronomy Now

Nearly four billion years ago, life arose on Earth. Life appeared because our planet had a rocky surface, liquid water, a blanketing atmosphere and a protective magnetic field. A new study of the young, Sun-like star Kappa Ceti shows that a magnetic field plays a key role in making a planet conducive to life.

Unexpected changes of bright spots on Ceres discovered

16 March 2016 Astronomy Now

New and very precise observations using the HARPS spectrograph with the ESO 3.6-metre telescope in Chile have not only detected the motion of the enigmatic bright spots on Ceres due to the dwarf planet’s rotation about its axis, but also found unexpected additional variations suggesting that the material of the spots is volatile and evaporates in sunlight.

Violent red flashes seen from black hole V404 Cygni

16 March 2016 Astronomy Now

In June 2015, V404 Cygni underwent dramatic brightening for about two weeks, as it devoured material that it had stripped off an orbiting companion star. Violent red flashes, lasting just fractions of a second, were observed during the flare-up — one of the brightest black hole outbursts in recent years.

How to detect colliding black holes

15 March 2016 Astronomy Now

Shortly to be honoured with a Bessel Award of the Humboldt Foundation, Professor Harald Pfeiffer’s research into solving Einstein’s equations on supercomputers not only helps us locate black holes in the Universe and determine their size, but his calculations also teach us how space-time behaves when it is warped by black holes.

Researchers propose a new model for dark matter

15 March 2016 Astronomy Now

Indisputable physical calculations state that approximately 27 percent of the universe is dark matter, but there are indications that we might never see it. Now researchers in Denmark turn this somehow depressing scenario into an advantage and propose a new model for what dark matter might be — and how to test it.

Cassini sees tilted terminator of Saturn’s moon Enceladus

14 March 2016 Astronomy Now

NASA’s Cassini spacecraft captured this view of Saturn’s moon Enceladus that shows wrinkled plains that are remarkably youthful in appearance, being generally free of large impact craters.

Disco lights from a galaxy cluster seen with multi-spectral eyes

14 March 2016 Astronomy Now

MACS J0717, some 5.4 billion light-years away from Earth in the constellation of Auriga (The Charioteer), is the result of four galaxy clusters colliding. This image is a combination of observations in visible light, X-rays and radio waves from the NASA/ESA Hubble Space Telescope, NASA’s Chandra X-ray Observatory, and the NRAO Jansky Very Large Array.

Telescopes combine to push frontier on galaxy clusters

12 March 2016 Astronomy Now

Galaxy clusters are enormous collections of hundreds or even thousands of galaxies and vast reservoirs of hot gas embedded in massive clouds of dark matter. To learn more about clusters, including how they grow via collisions, astronomers have used some of the world’s most powerful X-ray, optical and radio telescopes. The name for this galaxy cluster project is the “Frontier Fields”.