astronomy

A globular cluster of stars known as Palomar 12.

Although it currently resides on the outskirts of the Milky Way’s halo, Palomar 12 was not born here. When astronomers first studied this cluster, they were puzzled by its strangely young age when compared to the other clusters within the galaxy. It appeared to be around 30 percent younger than other Milky Way globulars.

It was revealed that Palomar 12 was actually ripped from its initial home, the Sagittarius Dwarf Elliptical galaxy, around 1.7 billion years ago via tidal interactions between its former home and our galaxy. The dwarf galaxy that Palomar 12 once called home is a satellite galaxy to ours, and closely orbits around us — even occasionally passing through the plane of our galaxy. In fact, it is being slowly torn apart and consumed by the Milky Way.

Credit: ESA/NASA/Hubble Space Telescope

Amazing shot of the northern lights dancing over Denali National Park in Alaska. In this pic, the aurora borealis shares the night sky with a meteor, the constellation Orion and Jupiter. Photo courtesy of Dan Leifheit.

Superfluid in Neutron Star’s Core

One of the most famous astronomical objects in the night sky is the Cassiopeia A supernova remnant. This image of Cassiopeia A was taken with NASA’s Chandra X-ray Observatory and shows three different energy bands of X-ray light. The white dot in the center of the image is Cassiopeia A’s neutron star. A neutron star is fast spinning, ultradense stellar remnant that’s left over after a massive star explodes. In fact, it’s the densest known object that is directly observable. Because it’s compressed by its immense gravitational field, a single teaspoon of neutron star material would weigh about 10 million tons. The pressure inside the core is high enough that most of the electrons there are forced into a degenerate state; they penetrate the atomic nuclei and fuse with protons, producing neutrons and a tremendous amount of energy, which is mainly radiated in the form of neutrinos. The rapid cooling in Cas A’s neutron star — through neutrino emission, suggests that the neutrons in its core are in a rare form of matter known as a superfluid. Superfluids are very strange, they are friction-free, can flow upward, escape airtight containers, and also behave as if they are a single particle.

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Credit: NASA/CXC/SAO

Dark Energy Camera Catches Breathtaking Glimpse of Comet Lovejoy


On December 27, 2014, while scanning the southern sky as part of the Dark Energy Survey, researchers snapped the above shot of comet Lovejoy. The image above was captured using the 570-megapixel Dark Energy Camera, the world’s most powerful digital camera. Each of the rectangular shapes above represents one of the 62 individual fields of the camera.

At the time this image was taken, the comet was passing about 51 million miles from Earth – a short distance for the Dark Energy Camera, which is sensitive to light up to 8 billion light years away. The comet’s center is a ball of ice roughly three miles across, and the visible head of the comet is a cloud of gas and dust about 400,000 miles in diameter.