Using colors to identify the approximate ages of more than 130,000 stars in the Milky Way's halo, Notre Dame astronomers have produced the clearest picture yet of how the galaxy formed more than 13.5 billion years ago.
If two galaxies collide, the merging of their central black holes triggers gravitational waves, which ripple throughout space. An international research team has now calculated that this occurs around 10 million years after the two galaxies merge - much faster than previously assumed.
The center of the Milky Way galaxy is currently a quiet place where a supermassive black hole slumbers, only occasionally slurping small sips of hydrogen gas. But it wasn't always this way. A new study shows that 6 million years ago, when the first human ancestors known as hominins walked the Earth, our galaxy's core blazed forth furiously.
Located more than 12,000 light-years from Earth, the object first stood out as peculiar when it was observed at particular radio frequencies. Several teams of astronomers studied it using ground-based telescopes and concluded that it is an oxygen-rich star about 10 times as massive as the sun. The question was: What kind of star?
Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) surveyed dozens of young stars and discovered that the larger variety have surprisingly rich reservoirs of carbon monoxide gas in their debris disks. In contrast, the lower-mass, Sun-like stars have debris disks that are virtually gas-free.
Speculating about what aliens look like has kept children, film producers and scientists amused for decades. If they exist, will extra terrestrials turn out to look similar to us, or might they take a form beyond our wildest imaginings? The answer to this question really depends on how we think evolution works at the deepest level.
The distant planet GJ 1132b intrigued astronomers when it was discovered last year. Located just 39 light-years from Earth, it might have an atmosphere despite being baked to a temperature of around 450 degrees Fahrenheit.