Depending on where you live in the British Isles, you may be fortunate to view a lunar occultation of naked-eye double star delta (δ) Geminorum at dawn on Tuesday, 27 August 2019. Observers fortunate enough to lie on the so-called graze line will see the star appear to flicker on and off as the mountains and valleys of the northern lunar polar regions drift by.
Observers in the British Isles can rejoice that summer astronomical twilight all night is drawing to a close. But if Jupiter and Saturn are currently too low to view, you’re blighted by light pollution, or moonlight robs you of nebulae, why not seek out some of the many beautiful double and multiple stars on show?
If you’re bemoaning the current dearth of bright planets in the evening sky, or light pollution prevents you from viewing a multitude of spring galaxies, don’t give up – there are always attractively coloured double and multiple stars to view. Join us on a tour of the Northern Hemisphere constellation of Boötes (pronounced Bo-oh-tees), the Herdsman, easily located due to its brightest star, Arcturus.
Astronomers have discovered a new type of exotic binary star. In the system AR Scorpii a rapidly spinning white dwarf star powers electrons up to almost the speed of light. These high energy particles release blasts of radiation that lash the companion red dwarf star, and cause the entire system to pulse dramatically every 1.97 minutes with radiation ranging from the ultraviolet to radio.
A new analysis of 13 supernovae — including archived data from NASA’s Hubble Space Telescope — is helping astronomers explain how some young stars exploded sooner than expected, hurling them to a lonely place far from their host galaxies. It’s a complicated mystery of double-star systems, merging galaxies, and twin black holes.