The Center for Astrophysics (CfA) provides world-class opportunities for academic training and career development in astrophysics. It is home to the Harvard University Department of Astronomy, which ...

Stars have a life cycle: they’re born, they pass through middle age, and they die. The birth of a star determines much of how it lives that life. For that reason, researchers study star-forming ...

Galaxy clusters are the largest objects in the universe that are held together by their own gravity. They contain hundreds or thousands of galaxies, lots of hot plasma, and a large amount of invisible ...

Our modern understanding of gravity comes from Albert Einstein’s theory of general relativity, which stands as one of the best-tested theories in science. General relativity predicted many phenomena ...

Our knowledge of the events and forces that shaped the early Universe is dependent on our ability to understand the most extreme conditions. On one hand, the Universe’s origin was incomprehensibly ...

Everything you’ve ever seen or experienced on Earth was once a nebulous collection of floating gas and dust. Science is starting to understand how those particles came to take the forms you recognize ...

Galaxies are home to most of the stars in the universe, and they form the beads of the cosmic jewelry that defines structure on the largest scales. But galaxies haven’t always been around, and they ...

Matter and energy are the two basic components of the entire Universe. An enormous challenge for scientists is that most of the matter in the Universe is invisible and the source of most of the energy ...

Large galaxies like the Milky Way formed out of mergers with smaller galaxies and by stealing some of their stars. Astronomers discovered that as many as 25% of galaxies are currently merging with ...

For the first 380,000 years or so after the Big Bang, the entire universe was a hot soup of particles and photons, too dense for light to travel very far. However, as the cosmos expanded, it cooled ...

Supernovas are some of the brightest events in the universe, occasionally outshining entire galaxies at their peak. Many supernovas can be seen from billions of light-years away, and nearby supernovas ...

The Milky Way alone probably contains hundreds of billions of planets, based on the thousands of exoplanets we’ve already identified. These planets share a history and origin with their host stars, ...