Drew Ex Machina 29 Mar 2017, 12:50 UTC Over the past couple of decades, the pace of exoplanet discoveries has accelerated with literally thousands of extrasolar planets currently known. Today there are numerous databases available where researchers or even interested lay people can scan through the basic properties of all the known exoplanets. One of the underappreciated aspects about these listed properties is how their values are frequently dependent on (and limited by) what we know about the exoplanet’s parent star.
Astronaut.com 29 Mar 2017, 12:47 UTC At 10:49pm Western Australian time on February 2 this year, cosmic gamma rays hit the NASA satellite, Swift, orbiting the Earth. Within seconds of the detection, an alert was automatically sent to the University of WA’s Zadko Telescope. It swung into robotic action, taking images of the sky location in the constellation Ophiuchus. What emerged from the blackness, where nothing was seen before, was a rapidly brightening “optical transient”, which is something visible in the sky for a brief period of time.
One Universe at a Time 29 Mar 2017, 11:00 UTC Young galaxies are often surrounded by a halo of hydrogen gas. Over time this gas can be pulled inward, where it can feed star production in the galaxy. While we’ve known these halos existed, it has been difficult to determine their size. But new research from the Atacama Large Millimeter/submillimeter Array (ALMA) has found that some galactic halos are surprisingly large. Light from the galaxy (green) is widely separated from the quasar (red), which indicates a large super-halo around the galaxy.
EarthSky Blog 29 Mar 2017, 10:01 UTC This optical image shows the Was 49 system, which consists of a large galaxy merging with a much smaller galaxy. The dwarf galaxy rotates within the larger galaxy’s disk, about 26,000 light-years from its center. The pink-colored region indicates a feeding supermassive black hole; the green color indicates normal starlight.
Space Fellowship 29 Mar 2017, 05:20 UTC Four laser beams cut across this startling image of the Orion Nebula, as seen from ESO’s Paranal Observatory in the Atacama desert on planet Earth. Not part of an interstellar conflict, the lasers are being used for an observation of Orion by UT4, one of the observatory’s very large telescopes, in a technical test of an image-sharpening adaptive optics system. This view of the nebula with laser beams was captured by a small telescope from outside the UT4 enclosure.
Sky and Telescope 29 Mar 2017, 00:49 UTC Researchers have used data from the Rosetta mission to link outbursts on Comet 67P/Churyumov-Gerasimenko with dramatic surface changes. A "Rosetta selfie" snapped by the Comet Infrared Visible Analyser (CIVA) aboard Philae in 2014, with Comet 67P in the background. ESA/Rosetta/Philae/CIVA What's it like to ride along with a comet during a tumultuous pass near the Sun? Images from the late Rosetta spacecraft revealed just such a view, showing how the surface of Comet 67P/Churyumov-Gerasimenko has changed over time. Comets are notorious for sudden outbursts as they near the Sun. Comets are even known for occasionally fragmenting as they approach the inner solar system. To date, the exact mechanism for such outbursts was poorly understood. Landslides were frequently evoked, though never witnessed. On July 10, 2015, researchers got their chance, when Rosetta's navigation camera caught a large plume occurring on Comet 67P. Then, just five days later, Rosetta caught sight of a fresh, bright exposed escarpment in the Seth region of the comet along the 134-meter-high Aswan cliff. The albedo (reflectivity) of the exposed material was 40% (the same as dry sand), versus the murky 6% albedo for the old, dirty snowball surface of the comet. Anatomy of a comet outburst: ...
Astro Bob 28 Mar 2017, 17:46 UTC The northern lights should return for a second show tonight starting at nightfall and continuing through about 10 p.m. Central time. Last night’s display, lovely as it was, ended so quickly it took many aurora watchers by surprise. When seeking signs of the lights, keep an eye on the north. Almost every show begins with a low, greenish arc often hidden by trees but revealed when you find an observing spot with an open view to the north.
AAS Nova 28 Mar 2017, 16:00 UTC Editor’s note: Astrobites is a graduate-student-run organization that digests astrophysical literature for undergraduate students. As part of the partnership between the AAS and astrobites, we repost astrobites content here at AAS Nova once a week. We hope you enjoy this post from astrobites; the original can be viewed at astrobites.org! Title: The Remarkable Similarity of Massive Galaxy Clusters from z~0 to z~1.9 Authors: Michael McDonald, Steve W. Allen, Matt Bayliss et al. First Author’s Institution: Kavli Institute for Astrophysics and Space Research, MIT Status: Submitted to ApJ, open access Introducing … Galaxy Clusters and X-Rays! We have come a long way since the 1930s, when the words ‘galaxy cluster‘ were posited for the first time by Fritz Zwicky in relation with the presence of dark matter in the Coma cluster. Developments in multi-wavelength astrophysics have allowed us to probe different components of a cluster with different telescopes. For example, star-forming galaxies of galaxy clusters are observed using optical telescopes because starlight in these galaxies loves emitting photons with the roughly the same energy as that which we see from the Sun. Other galaxies are super-red, have no star-formation, and have a ton of dust; these are best viewed with infrared ...