A near-record 17-billion-solar-mass black hole discovered in a sparse area of the local universe indicates that these monster objects may be more common than once thought. The newly discovered supermassive black hole is in NGC 1600, an elliptical galaxy in the constellation Eridanus some 149 million light-years away.
An international team of scientists has found radioactive iron-60 in sediment and crust samples taken from the Pacific, Atlantic and Indian Oceans. They report that a series of massive supernova explosions occurring between 3.2 and 1.7 million years ago from stars less than 300 light-years away showered the Earth with radioactive debris.
Much of the action on Mars occurred during a period known as the Late Heavy Bombardment about 3.9 billion years ago. Large comets and asteroids raining down on the planet would have produced enough heat to melt subsurface ice, likely enhancing climate conditions enough to make Mars more conducive to life — at least for a time.
While truly massive stars go out in a blaze of glory, intermediate-mass stars — those between roughly one and eight times the mass of the Sun — are somewhat quieter. Such stars eventually form cosmic objects known as planetary nebulae, so named because of their vague resemblance to planets when seen through early, low-resolution telescopes.
New results from NANOGrav — the North American Nanohertz Observatory for Gravitational Waves — establish astrophysically significant limits in the search for low-frequency gravitational waves. This result provides insight into how often galaxies merge and how those merging galaxies evolve over time.
Fast radio bursts (or FRBs) are brief yet powerful spurts of radio energy lasting only a few milliseconds. They were first identified in 2007 and their source has remained a mystery. New research shows that the radio emission believed to be an afterglow from FRB 150418 actually originated from a distant galaxy’s core and was unassociated with the FRB.
Those of us living in cities, towns and villages are subject to varying degrees of light pollution — the inappropriate use of artificial light at night. But we don’t have to lose our stars as there are ways to mitigate the skyglow. Learn what you can do to help during International Dark Sky Week, 4—10 April.
According to new research, the salt levels of oceans on distant Earth-like planets could have a major effect on their climates. Computer models reveal that exoplanets with very saline oceans could have circulation patterns opposite to that on Earth, resulting in dramatic warming of their polar regions, possibly extending their range of habitability.
This striking NASA/ESA Hubble Space Telescope image depicts the low surface brightness (LSB) galaxy known as UGC 477, located just over 110 million light-years away in the constellation of Pisces. LSB galaxies appear to be dominated by dark matter, making them excellent objects to study to further our understanding of this elusive substance.
Researchers have discovered a white dwarf star with an atmosphere dominated by oxygen — a type of white dwarf that has been theorised to exist but not identified to date. The finding could challenge the textbook wisdom of single stellar evolution, and provide a critical link to some types of supernovae discovered over the past decade.
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