Is a sun a star or a planet? While science now agrees the sun is a star, new telescopes may soon challenge how we define ...

About 50 light-years from Earth, a gas giant about half the mass of Jupiter orbits a sunlike star. The discovery of Pegasi 51 ...

Astronomers have discovered that aging stars may be devouring their closest giant planets as they swell into red giants.

There has been a lot of back and forth about the existence of a mysterious ninth planet, often referred to as "Planet Nine" or even "Planet X." Now, though, researchers say there is likely at least a ...

Planets may begin forming much earlier than scientists once believed during the final stages of a star s birth, not afterward. This bold new model, backed by simulations from researchers at SwRI, ...

A team of scientists at the Institute for Advanced Study School of Natural Sciences in Princeton, New Jersey, might have found a new dwarf planet, potentially leading to more evidence of a theoretical ...

A possible new dwarf planet has been discovered at the edge of our solar system, so far-flung that it takes around 25,000 years to complete one orbit around the sun. The object, known as 2017 OF201, ...

Is there a massive undiscovered planet on the outer reaches of the solar system? The idea has been around since before the discovery of Pluto in the 1930s. Labeled as planet X, prominent astronomers ...

Mike Brown is convinced that beyond Neptune, at the far reaches of our solar system, there's an unseen giant planet. "This is the 5th largest planet in our solar system, lurking out there, waiting to ...

Multiple planets will appear close together in the sky, beginning on Friday, Feb. 28, and the Cranbrook Institute of Science in Bloomfield Hills is planning a celebration. Experts call it a planetary ...