2013: Year in Space (31 images)

Stars can become remarkably photogenic at the end of their life, like NGC 2392, the "eskimo nebula", which is located about 4,200 light years from Earth. Planetary nebulas like NGC 2392, form when a star uses up all of the hydrogen in its core. When this happens, the star begins to cool and expand and the outer layers of the star are carried away by a thick 50,000 kilometer per hour wind, leaving behind a hot core with a surface temperature of about 50,000 degrees Celsius. The radiation from the hot star and the interaction of its fast wind with the slower wind creates the shell of a planetary nebula. Eventually the remnant star will collapse to form a white dwarf star. UPI/NASA

Lying over 110 million light-years away from Earth in the constellation of Antlia (The Air Pump) is the spiral galaxy IC 2560, shown here in an image from NASA/ESA Hubble Space Telescope released September 9th 2013. At this distance it is a relatively nearby spiral galaxy, and is part of the Antlia cluster which is a group of over 200 galaxies held together by gravity. This cluster is unusual; unlike most other galaxy clusters, it appears to have no dominant galaxy within it. In this image, it is easy to spot IC 2560's spiral arms and barred structure. This spiral is what astronomers call a Seyfert-2 galaxy, a kind of spiral galaxy characterised by an extremely bright nucleus and very strong emission lines from certain elements of hydrogen, helium, nitrogen, and oxygen. The bright center of the galaxy is thought to be caused by the ejection of huge amounts of super-hot gas from the region around a central black hole. UPI

This artist's rendition of NuSTAR, along with never seen data from the black hole hunting telescope was released to the public for the first time by NASA on August 29th, 2013. The Nuclear Spectroscopic Telescope Array, or NuSTAR, is giving the wider astronomical community a first look at its unique X-ray images of the cosmos via NASA's High Energy Astrophysics Science Archive Research Center, or HEASARC. UPI/NASA

The Sculptor galaxy is seen in a new light, in this composite image from NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) and the European Southern Observatory in Chile, that was released recently. Visible data from the European Space Observatory show the backbone of the galaxy made up of stars, while NuSTAR data, which appear as colored blobs, show high-energy X-rays. The findings suggest that the supermassive black hole at the center of the Sculptor galaxy, also known as NGC 253, has dozed off, or gone inactive, sometime in the past decade. The NuSTAR data also reveals a flaring source of high-energy X-rays, called an ultraluminous X-ray source, or ULX. This object, which appears as a blue spot near the hotter, central region of the galaxy, is either a black hole or a dense, dead star, called a neutron star, feeding off a partner star. The other orange and reddish points are likely additional X-ray-generating pairs of stars located throughout the galaxy. In this image, red shows low-energy X-ray radiation (3 to 7 kiloelectron volts), green is medium energy (7 to 10 kiloelectron volts), and blue is high energy (10 to 20 kiloelectron volts). NASA/JPL-Caltech/JHU