NASA’s NICER instrument reveals that neutron stars are not as simple as we thought. Pulsars are the lighthouses of the universe. These tiny, compact objects are neutron stars — the remnants of once-massive stars — that spin rapidly, beaming radiation … Read More
Monsters lurk in the cores of all galaxies: supermassive black holes millions or billions of times the mass of our Sun. And as galaxies merge, so, too, do these black holes, which gradually approach each other over millions of years. … Read More
Imaged by the Gemini Observatory in Hawaii, the galaxies NGC 5394 (the smaller one, on the right) and NGC 5395 (the larger one, on the left) are in the middle of colliding over the span of millions of years. It … Read More
A rare nova visible to the eye If you look carefully into the night sky, you might spot a star that wasn’t visible last week. A star named RS Ophiuchi, located about 4,566 light-years away in the equatorial constellation of … Read More
It was only 25 years ago, when astronomers discovered that the Universe was expanding at an accelerated rate. Without an obvious cause, the concept of dark energy was introduced. Dark energy exerts a force on the universe and is thought … Read More
In 2017, a strangely shaped object whizzed past the Sun and Earth on a trajectory from beyond our Solar System, triggering wild speculation. Most scientists believe the cigar-shaped visitor, which measured less than a kilometer in length, was a comet … Read More