Many known exoplanets orbit close to their host star, within one-tenth of an astronomical unit (one AU is the average distance of the Earth from the Sun). Since their orbital periods are therefore very short and their gravitational influences on the host star’s wobble comparatively large, they can be readily detected by the transit and…

The distant planet GJ 1132b intrigued astronomers when it was discovered last year. Located just 39 light-years from Earth, it might have an atmosphere despite being baked to a temperature of around 450 degrees Fahrenheit. But would that atmosphere be thick and soupy or thin and wispy? New research suggests the latter is much more…

The universe is 13.8 billion years old, while our planet formed just 4.5 billion years ago. Some scientists think this time gap means that life on other planets could be billions of years older than ours. However, new theoretical work suggests that present-day life is actually premature from a cosmic perspective. “If you ask, ‘When…

Our Earth consists of silicate rocks and an iron core with a thin veneer of water and life. But the first potentially habitable worlds to form might have been very different. New research suggests that planet formation in the early universe might have created carbon planets consisting of graphite, carbides, and diamond. Astronomers might find…

Earlier this year scientists presented evidence for Planet Nine, a Neptune-mass planet in an elliptical orbit 10 times farther from our Sun than Pluto. Since then theorists have puzzled over how this planet could end up in such a distant orbit. New research by astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA) examines a number…

Young massive star clusters are systems of stars with more than about ten thousand solar-masses of material and ages less than about one hundred million years that are gravitationally bound together. In these clusters the stellar densities can reach and even exceed the densities found in stellar globular clusters, more evolved systems that host hundreds…

We live in a dramatic epoch of astrophysics. Breakthrough discoveries like exoplanets, gravity waves from merging black holes, or cosmic acceleration seem to arrive every decade, or even more often. But perhaps no discovery was more unexpected, mysterious, and challenging to our grasp of the “known universe” than the recognition that the vast majority of…

Nearly four billion years ago, life arose on Earth. Life appeared because our planet had a rocky surface, liquid water, and a blanketing atmosphere. But life thrived thanks to another necessary ingredient: the presence of a protective magnetic field. A new study of the young, Sun-like star Kappa Ceti shows that a magnetic field plays…

Super-massive black holes at the centers of galaxies can spawn tremendous bipolar jets when matter in the vicinity forms a hot, accreting disk around the black hole. The rapidly moving charged particles in the jets radiate when they are deflected by magnetic fields; these jets were discovered at radio wavelengths several decades ago. In the…

In April 2015, after traveling for about half the age of the universe, a flood of powerful gamma rays from a distant galaxy slammed into Earth’s atmosphere. That torrent generated a cascade of light – a shower that fell onto the waiting mirrors of the Very Energetic Radiation Imaging Telescope Array System (VERITAS) in Arizona.…

Most people think of black holes as giant vacuum cleaners sucking in everything that gets too close. But the supermassive black holes at the centers of galaxies are more like cosmic engines, converting energy from infalling matter into intense radiation that can outshine the combined light from all surrounding stars. If the black hole is…

Our Sun is a relatively quiet star that only occasionally releases solar flares or blasts of energetic particles that threaten satellites and power grids. You might think that smaller, cooler stars would be even more sedate. However, astronomers have now identified a tiny star with a monstrous temper. It shows evidence of much stronger flares…

In many ways stars are like living beings. They’re born; they live; they die. And they even have a heartbeat. Using a novel technique, astronomers have detected thousands of stellar “pulses” in the galaxy Messier 87 (M87). Their measurements offer a new way of determining a galaxy’s age. We tend to think of stars as…

When astronomers study protoplanetary disks of gas and dust that surround young stars, they sometimes spot a dark gap like the Cassini division in Saturn’s rings. It has been suggested that any gap must be caused by an unseen planet that formed in the disk and carved out material from its surroundings. However, new research…

Cambridge, MA -Move over, Matrix – astronomers have done you one better. They have created the first realistic virtual universe using a computer simulation called “Illustris.” Illustris can recreate 13 billion years of cosmic evolution in a cube 350 million light-years on a side with unprecedented resolution. “Until now, no single simulation was able to…