SpaceTime

Light Echo around SN 2014J in M82 . Credits NASA , ESA , and Y. Yang (Texas A&M University and Weizmann Institute of Science, Israel). Acknowledgment: M. Mountain (AURA) and The Hubble Heritage Team ( STScI /AURA) Light from a supernova explosion in the nearby starburst galaxy M82 is reverberating off a huge dust cloud in interstellar space. The supernova, called SN 2014J, occurred at the upper right of M82, and is marked by an “X.” The supernova was discovered on Jan. 21, 2014.  The inset images at top reveal an expanding shell of light from the stellar explosion sweeping through interstellar space, called a “light echo.” The images were taken 10 months to nearly two years after the violent event (Nov. 6, 2014 to Oct. 12, 2016). The light is bouncing off a giant dust cloud that extends 300 to 1,600 light-years from the supernova and is being reflected toward Earth. SN 2014J is classified as a Type Ia supernova and is the closest such blast in at least four ...

Figure: Called the Veil Nebula, the debris is one of the best-known supernova remnants, deriving its name from its delicate, draped filamentary structures. This view is a mosaic of six Hubble pictures of a small area roughly two light-years across, covering only a tiny fraction of the nebula’s vast structure. Credit: NASA/ESA/Hubble Heritage Team The presence and abundance of short lived radioisotopes in chondritic meteorites implies that the Sun formed in the vicinity of one or more massive stars that exploded as supernovae (SNe).

Image: Supernova remnant N 63A. Credit: NASA/ESA/HEIC and The Hubble Heritage Team (STScI/AURA) Models for supernovae (SNe) related to thermonuclear explosions of white dwarfs (WDs) have been extensively studied over the last few decades, mostly focusing on single degenerate (accretion of material of a WD) and double degenerate (WD-WD merger) scenarios.

Figure: False-Colour X-ray and infrared emission image from the core of the infrared shell. The RGB colours correspond to Chandra X-ray 0.2-10 keV (blue), IRAC infrared 8 μm (green), and HPACS 70 μm (red) data. The intensity scale is logarithmic for all channels. Overlaid are equal brightness levels from the MIPS 24 μm band. Note that around the CCO the infrared emission is suppressed in the 70 μm band and enhanced in the 24 μm band suggesting higher dust temperature. Credit: Doroshenko et al 2016 Central compact objects (CCOs) are thought to be young isolated neutron stars that were born during the preceding core-collapse supernova explosion.

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: Combined HST and Chnadra imaging of the supernova remnant SNR 0509-67.5 in the LMC To find distances in space, astronomers use objects called "standard candles", objects that give a certain, known amount of light. Because astronomers know how bright these objects truly are, they can measure their distance from us by analyzing how dim they appear.

Image: Artistic representation of Doulbe Neutron Stars. Credit: NASA/Goddard Space Flight Center Double Neutron Stars (DNS) have to survive two supernovae and still remain bound. For this reason these systems are a unique and rare population of neutron stars and sets strong limits on the nature of the second collapse. Moreover, DNS emit gravitational radiation and consequently their orbit decays and they merge. This make DNS systems prime candidates for detection of gravitational radiation.

Credit: ALMA (ESO/NAOJ/NRAO)/Alexandra Angelich (NRAO/AUI/NSF) Only a small amount of the supernovae products remains trapped within globular clusters and this "catch" only occurs in the most massive cases (mass cluster ≥ 10^6 solar masses).