恒星

The glittering, glitzy contents of the globular cluster NGC 6652 sparkle in this star-studded image from the NASA/ESA Hubble Space Telescope. The core of the cluster is suffused with the pale blue light of countless stars, and a handful of particularly bright foreground stars are adorned with crisscrossing diffraction spikes. NGC 6652 lies in our own Milky Way galaxy in the constellation Sagittarius, just under 30,000 light-years from Earth and only 6,500 light-years from the galactic center. Globular clusters are stable, tightly gravitationally bound clusters containing anywhere from tens of thousands to millions of stars. The intense gravitational attraction between closely packed stars in globular clusters is what gives these star-studded objects their regular, spherical shape. This image combines data from two of Hubble’s most…

The teeming stars of the globular cluster NGC 6544 glisten in this image from the NASA/ESA Hubble Space Telescope. This cluster of tightly bound stars lies more than 8,000 light-years away from Earth and is, like all globular clusters, a densely populated region of tens of thousands of stars. This image of NGC 6544 combines data from two of Hubble’s instruments, the Advanced Camera for Surveys and Wide Field Camera 3, as well as two separate astronomical observations. The first observation was designed to find a visible counterpart to the radio pulsar discovered in NGC 6544. A pulsar is the rapidly spinning remnant of a dead star, emitting twin beams of electromagnetic radiation like a vast astronomical lighthouse. This pulsar rotates particularly quickly, and astronomers…

The densely packed globular cluster NGC 6325 glistens in this image from the NASA/ESA Hubble Space Telescope. This concentrated group of stars lies around 26,000 light-years from Earth in the constellation Ophiuchus. Globular clusters like NGC 6325 are tightly bound collections of stars with anywhere from tens of thousands to millions of members. They can be found in all types of galaxies and act as natural laboratories for astronomers studying star formation. This is because the constituent stars of globular clusters tend to form at roughly the same time and with similar initial composition, meaning astronomers can use them to fine-tune their theories of how stars evolve. Astronomers inspected this particular cluster not to understand star formation, but to search for a hidden monster. Though…