The Universe

In 2015, an astrophysicist discovered that the star would undergo irregular dips in brightness over a period of days or weeks.

"We have never seen anything like this in the 24 years we have studied the supermassive black hole," researcher Andrea Ghez said.

Astronomers found a "runaway star," dubbed PG 1610+062, in the outer halo of the Milky Way.

Researchers detected gravitational waves—ripples in space-time—emanating from a cataclysmic event around 900 million light years away.

Dark matter is mysterious substance that appears to make up about 27 percent of the universe's mass.

The exoplanet, dubbed WASP-121b, is located around 900 light-years from Earth.

The three planets are among the smallest and closest exoplanets found to date, according to astronomers.

"This has been one of the rare opportunities when the signs of aging could be directly observed in a star over human timescales," Meridith Joyce said.

A team of astronomers has discovered the "fastest eclipsing white dwarf binary" star system in the known universe.

Astronomers have cast new light on a huge, empty expanse of space that surrounds our galaxy known as the Local Void.

The observatory is expected to map around 100,000 galaxy clusters—the largest known gravitationally bound structures in the universe—and three million supermassive black holes.

The black hole is located at the center of the spiral galaxy NGC 3147 around 130 million light-years away from Earth.

Einstein's general theory of relativity beautifully describes the nature of gravity and its effect on large objects in the universe. However, there are alternative explanations.

Astronomers have measured the spin rate of five, distant supermassive black holes for a study published in the Astrophysical Journal.

Our universe is made up of three spatial dimensions—width, depth and height—as well as the additional dimension of time.

The Teegarden star—a red dwarf with a mass less than a tenth that of the sun—is located just 12.5 light-years away in the constellation Aries.

Before its mission ended in September 2017, NASA's Cassini probe conducted a series of dives between Saturn's cloud tops and its rings.

Gamma-ray bursts are some of the most extreme events in the universe, producing vast jets of powerful radiation that can be detected billions of light-years from their source.

The ocean is thought to be be billions of years old and may contain as much as three times the volume of all the liquid water on Earth.

Build-ups of toxic gases in the atmospheres of many exoplanets in the "habitable zone" could limit the "safe zone" in which life outside our solar system could actually exist.

The findings expand our knowledge of black holes and the galaxies within which they are often found.

Messier 90 belongs to a vast collection of more than 1,200 galaxies known as the Virgo Cluster, which has a diameter of 15 million light-years.

There are three different physical processes responsible for accelerating particles to vast speeds.

"We usually think of spiral galaxies as being quite flat."

The origin of this rarely observed ultra-high-energy phenomenon has puzzled scientists for decades.

Astronomers have spotted a black hole spewing out vast amounts of incredibly cold gas.

Researchers say they have detected remnants of a universe that existed before our own.

The image features around 15,000 galaxies, the oldest of which dates back to 11 billion years ago.

The hungry star, known as RW Aur A, is located around 450 light-years from Earth.

The study has proved the theory holds beyond the Milky Way.