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Image: The Kuiper Belt. Credit: NASA . The Kuiper belt is a circumstellar disc in the Solar System beyond the planets, extending from the orbit of Neptune (at 30 AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt (the circumstellar disc located roughly between the orbits of the planets Mars and Jupiter), but it is far larger-20 times as wide and 20 to 200 times as massive.

Image: The colour image of the galaxy NGC 4569 in the Virgo cluster, obtained with MegaCam at the CFHT. The red filaments at the right of the galaxy show the ionised gas removed by ram pressure. This is about 95% of the gas reservoir of the galaxy needed to feed the formation of new stars  Credit: CFHT/Coelum Messier 90 (also known as M90 and NGC 4569) is a member of the Virgo cluster and one of its largest and brightest spiral galaxies, about 60 million light-years away.

Image: Two black holes are entwined in a gravitational tango in this artist's conception. Credit: NASA A binary black hole (BBH) is a system consisting of two black holes in close orbit around each other. Binary black holes are often divided into stellar binary black holes, formed either as remnants of high-mass binary star systems or by dynamic processes and mutual capture, and binary supermassive black holes believed to be a result of galactic mergers.

Image: An illustration of the cosmic web. Credit: NASA/NCSA University of Illinois Visualization by Frank Summers, Space Telescope Science Institute, Simulation by Martin White and Lars Hernquist, Harvard University The distribution of galaxies in the Universe forms a vast network of interconnected filamentary structures, sheets, and clusters which are separated by immense voids. This vast foam-like structure sometimes is called the "cosmic web".

Image: The sequence illustrates the macronova model for the formation of a short-duration gamma-ray burst. 1. A pair of neutron stars in a binary system spiral together. 2. In the final milliseconds, as the two objects merge, they kick out highly radioactive material. This material heats up and expands, emitting a burst of light called a macronova. 3. The fading fireball blocks visible light but radiates in infrared light. 4. A remnant disk of debris surrounds the merged object, which may have collapsed to form a black hole Credit: NASA, ESA, and A. Feild (STScI) A macronova (also called a 'kilonova' or an 'r-process supernova' ) occurs when two neutron stars or a neutron star and a black hole merge. It is a near-infrared/optical transient powered by the radioactive decay of heavy elements synthesized in the ejecta (~10 -4 -10 -1 M sun with velocities ~ 0.1-0.3c) of a compact binary merger. Strong electromagnetic radiation is emitted due to the decay of h...

Image: At a distance of about 20,000 light years, G292.0+1.8 is one of only three supernova remnants in the Milky Way known to contain large amounts of oxygen. These oxygen-rich supernovas are of great interest to astronomers because they are one of the primary sources of the heavy elements (that is, everything other than hydrogen and helium) necessary to form planets and people. The X-ray image from Chandra shows a rapidly expanding, intricately structured, debris field that contains, along with oxygen (yellow and orange), other elements such as magnesium (green) and silicon and sulfur (blue) that were forged in the star before it exploded. Credit: NASA/CXC/SAO The processes of particles acceleration to very high energies from the supernova shock region and diffusion in the interstellar medium of such particles has not been well understood so far. Gamma-ray observations in the GeV regime are a powerful probe of these mechanisms

Image: The magenta spots in this image indicate two black holes in the spiral galaxy called NGC 1313, the Topsy Turvy galaxy. Both black holes belong to a class called ultraluminous X-ray sources, or ULXs. The magenta X-ray data come from NASA's Nuclear Spectroscopic Telescopic Array (NuSTAR) and are overlaid on a visible image from the Digitized Sky Survey. ULXs consist of black holes actively accreting, or feeding, off material drawn in from a partner star. Astronomers are trying to figure out why ULXs shine so brightly with X-rays. NuSTAR's new high-energy X-ray data on NGC 1313 helped narrow down the masses of the black holes in the ULXs: the black hole closer to the center of the galaxy is about 70 to 100 times that of our sun. The other black hole is probably smaller, about 30 solar masses. The Topsy Turvy galaxy is located about 13 million light-years away in the Reticulum constellation. Credit: NASA's Goddard Space Flight Center/JPL-Caltech/IRAP An Ultra-Lum...

A composite image of the HD 142527 binary star system from data captured by ALMA shows a distinctive arc of dust (red) and a ring of carbon monoxide (blue and green). The red arc is free of gas, suggesting the carbon monoxide has "frozen out", forming a layer of frost on the dust grains in that region. Astronomers speculate this frost provides a boost to planet formation. The two dots in the center represent the two stars in the system. Credit: Andrea Isella/Rice University; B. Saxton (NRAO/AUI/NSF); ALMA (NRAO/ESO/NAOJ) The Atacama Large Millimeter/submillimeter Array (ALMA) has observed a new very early stage of planet formation around the binary star system HD 142527 (in the costellation of Lupus) and has provided fresh insights into the planet-forming potential of a binary system.