Red giant

Since the beginning of human history, people have understood that the sun is a central part of life as we know it. It's importance to countless mythological and cosmological systems across the globe is a testament to this. But as our understand of it matured, we came to learn that the sun was here long before us, and will be here long after we're gone. Having formed roughly 4.6 billion years ago, our sun began its life roughly 40 million years before our Earth had formed.

Scientists published research related to a red giant star explosion they witnessed in real-time-- a first for the history of astronomy.

Remember in late 2019, when the famous red star Betelgeuse suddenly and mysteriously began dimming in brightness? Astronomers studying a similar star - VY Canis Majoris, one of the largest and brightest stars in our galaxy - commented that it's "behaving a lot like Betelgeuse on steroids."

Arcturus is 113 times brighter than our sun, even though it's only a little bigger. What else should we know about this red giant?

Explore the different kinds of stars that populate the cosmos, from red giants to white dwarfs. See telescopic images of stars and learn about their features and evolution.

Solar flares are powerful blasts of radiation unleashed by the sun. When aimed directly at Earth, these eruptions can trigger geomagnetic storms and knock out power grids and communications. Here are some spectacular photos of solar flares.

The star system AR Scorpii was discovered 40 years ago, but it took a group of amateur astronomers to work out it was different. Bill Condie reports.