When galaxies collide, stars seldom crash into each other because they are still separated by enormous distances. But as this Hubble Space Telescope view of NGC 3256 shows, gas and dust in colliding galaxies can come together with spectacular consequences, triggering the formation of vast numbers of new stars and clusters. NGC 3256, located about 100 million light-years from Earth in the constellation of Vela, is the result of the collision of two Milky Way-size galaxies that began about 500 million years ago. It is now an especially luminous starburst galaxy oriented face-on to Earth and showing two distinct nuclei, one of them shrouded by gas and dust, surrounded by more than 1,000 bright star clusters embedded in crisscrossing dust lanes and a large disk of molecular gas. The two galaxies merging in NGC 3256 had similar masses and in a few hundred million years, astronomers say, the two cores will complete the merger to produce a single large elliptical galaxy.
Located some 22,000 light-years away in the southern constellation of Musca (The Fly), this tightly packed collection of stars — known as a globular cluster — goes by the name of NGC 4833. Globular clusters are thought to contain some of the oldest stars in our galaxy. This NASA/ESA Hubble Space Telescope image shows the dazzling stellar group in all its glory.
In many ways stars are like living beings. They’re born; they live; they die. And they even have a heartbeat. Near the end of their lifetime they begin to pulsate, increasing and decreasing their brightness by a large amount every few hundred days. Using a novel technique, astronomers have detected thousands of stellar “pulses” in the galaxy Messier 87 (M87). Their measurements offer a new way of determining a galaxy’s age.
In this NASA/ESA Hubble Space Telescope image we see the striking face-on spiral galaxy NGC 6814, whose luminous nucleus and spectacular sweeping arms are rippled with an intricate pattern of dark dust. The galaxy was discovered by William Herschel in 1788. NGC 6814 lies 74.4 million light-years away in the constellation of Aquila.