SN 1987A was a type II supernova in the Large Magellanic Cloud, a dwarf satellite galaxy of the Milky Way. It occurred approximately 51.4 kiloparsecs from Earth and was the closest observed supernova since Kepler's Supernova in 1604. Light and neutrinos from the explosion reached Earth on February 23, 1987 and was designated "SN 1987A" as the first supernova discovered that year. Its brightness peaked in May of that year, with an apparent magnitude of about 3.
The Large Magellanic Cloud (LMC) is a dwarf galaxy and satellite galaxy of the Milky Way. At a distance of around 50 kiloparsecs (163,000 light-years), the LMC is the second- or third-closest galaxy to the Milky Way, after the Sagittarius Dwarf Spheroidal (c. 16 kiloparsecs (52,000 light-years) away) and the possible dwarf irregular galaxy called the Canis Major Overdensity. Based on the D25 isophote at the B-band (445 nm wavelength of light), the Large Magellanic Cloud is about 9.86 kiloparsecs (32,200 light-years) across. It is roughly one-hundredth the mass of the Milky Way and is the fourth-largest galaxy in the Local Group, after the Andromeda Galaxy (M31), the Milky Way, and the Triangulum Galaxy (M33).
X-ray astronomy is an observational branch of astronomy which deals with the study of X-ray observation and detection from astronomical objects. X-radiation is absorbed by the Earth's atmosphere, so instruments to detect X-rays must be taken to high altitude by balloons, sounding rockets, and satellites. X-ray astronomy uses a type of space telescope that can see x-ray radiation which standard optical telescopes, such as the Mauna Kea Observatories, cannot.
The Crab Nebula is a supernova remnant and pulsar wind nebula in the constellation of Taurus. The common name comes from a drawing that somewhat resembled a crab with arms produced by William Parsons, 3rd Earl of Rosse, in 1842 or 1843 using a 36-inch (91 cm) telescope. The nebula was discovered by English astronomer John Bevis in 1731. It corresponds with a bright supernova observed in 1054 C.E. by Native American, Japanese, and Arabic stargazers ; this supernova was also recorded by Chinese astronomers as a guest star. The nebula was the first astronomical object identified that corresponds with a historically-observed supernova explosion.
The Small Magellanic Cloud (SMC) is a dwarf galaxy near the Milky Way. Classified as a dwarf irregular galaxy, the SMC has a D25 isophotal diameter of about 5.78 kiloparsecs (18,900 light-years), and contains several hundred million stars. It has a total mass of approximately 7 billion solar masses. At a distance of about 200,000 light-years, the SMC is among the nearest intergalactic neighbors of the Milky Way and is one of the most distant objects visible to the naked eye.
The Chandra X-ray Observatory (CXO), previously known as the Advanced X-ray Astrophysics Facility (AXAF), is a Flagship-class space telescope launched aboard the Space ShuttleColumbia during STS-93 by NASA on July 23, 1999. Chandra is sensitive to X-ray sources 100 times fainter than any previous X-ray telescope, enabled by the high angular resolution of its mirrors. Since the Earth's atmosphere absorbs the vast majority of X-rays, they are not detectable from Earth-based telescopes; therefore space-based telescopes are required to make these observations. Chandra is an Earth satellite in a 64-hour orbit, and its mission is ongoing as of 2024.
Centaurus A is a galaxy in the constellation of Centaurus. It was discovered in 1826 by Scottish astronomer James Dunlop from his home in Parramatta, in New South Wales, Australia. There is considerable debate in the literature regarding the galaxy's fundamental properties such as its Hubble type and distance. It is the closest radio galaxy to Earth, as well as the closest BL Lac object, so its active galactic nucleus has been extensively studied by professional astronomers. The galaxy is also the fifth-brightest in the sky, making it an ideal amateur astronomy target. It is only visible from the southern hemisphere and low northern latitudes.
Einstein Observatory (HEAO-2) was the first fully imaging X-ray telescope put into space and the second of NASA's three High Energy Astrophysical Observatories. Named HEAO B before launch, the observatory's name was changed to honor Albert Einstein upon its successfully attaining orbit.
Geminga is a gamma ray and x-ray pulsar source thought to be a neutron star approximately 250 parsecs from the Sun in the constellation Gemini.
Cassiopeia A (Cas A) is a supernova remnant (SNR) in the constellation Cassiopeia and the brightest extrasolar radio source in the sky at frequencies above 1 GHz. The supernova occurred approximately 11,000 light-years (3.4 kpc) away within the Milky Way; given the width of the Orion Arm, it lies in the next-nearest arm outwards, the Perseus Arm, about 30 degrees from the Galactic anticenter. The expanding cloud of material left over from the supernova now appears approximately 10 light-years (3 pc) across from Earth's perspective. It has been seen in wavelengths of visible light with amateur telescopes down to 234 mm (9.25 in) with filters.
SN 1572, or B Cassiopeiae, was a supernova of Type Ia in the constellation Cassiopeia, one of eight supernovae visible to the naked eye in historical records. It appeared in early November 1572 and was independently discovered by many individuals.
IC 443 is a galactic supernova remnant (SNR) in the constellation Gemini. On the plane of the sky, it is located near the star Eta Geminorum. Its distance is roughly 5,000 light years from Earth.
Leon P. Van Speybroeck was an American astronomer who served as Telescope Scientist for the Chandra X-Ray Observatory, which was launched into space aboard the Space Shuttle Columbia in 1998. Van Speybroek designed the mirrors that made possible its spectacular X-ray images of nearby and remote magical objects, including comets, exploding stars, jets of gas spewing from nearby black holes, and powerful quasars more than 10 billion light years from Earth. The data from Chandra prompted new discoveries about the evolution of galaxies, the nature of the black holes, dark matter, and the dimensions of the universe.
SGR 0526−66 is a soft gamma repeater (SGR), located in the Super-Nova Remnant (SNR) 0526−66.1, otherwise known as N49, in the Large Magellanic Cloud. It was the first soft gamma repeater discovered, and as of 2015, the only known located outside our galaxy. First detected in March 1979, it was located by using the measurement of the arrival time differences of the signal by the set of artificial satellites equipped with gamma ray detectors. The association with N49 can only be indirect: it seems clear that soft gamma repeaters form in young stellar clusters. It is not certain that the explosion that gave birth to SGR 0525-66 is also the one that produced the remnant N49.
PSR B1509−58 is a pulsar approximately 17,000 light-years away in the constellation of Circinus discovered by the Einstein X-Ray Observatory in 1982. Its diameter is only 12 miles (19 km). It is located in a Pulsar wind nebula created by itself, that was caused as a remnant of the Supernova (SNR) MSH 15−52 visual approximately 1,700 years ago at the southern celestial hemisphere not visible in the northern hemisphere. The nebula spans about 150 light years. The pulsar's spin rate is "almost 7 times per second".
Gamma-ray astronomy is a subfield of astronomy where scientists observe and study celestial objects and phenomena in outer space which emit cosmic electromagnetic radiation in the form of gamma rays, i.e. photons with the highest energies at the very shortest wavelengths. Radiation below 100 keV is classified as X-rays and is the subject of X-ray astronomy.
SN 1972E was a supernova in the galaxy NGC 5253 that was discovered 13 May 1972 with an apparent B magnitude of about 8.5, shortly after it had reached its maximum brightness. In terms of apparent brightness, it was the second-brightest supernova of any kind of the 20th century. It was observed for nearly 700 days, and it became the prototype object for the development of theoretical understanding of Type Ia supernovae.
Giuseppina "Pepi" Fabbiano is an American astrophysicist. She works in the High Energy Astrophysics Division, at the Smithsonian Astrophysical Observatory.
William Liller was an American astronomer, known for his research on "planetary nebulae, comets, asteroids, magnetic activity in cool stars, the optical identification of X-ray sources, and astro-archaeology."
A central compact object (CCO) is an x-ray source found near the center of a young, nearby supernova remnant (SNR). Given the observed x-ray flux and spectra observed from these objects, the almost certain conclusion is that CCOs are the remnant neutron stars which resulted from the recent supernova. Unlike most pulsars, CCOs generally lack pulsed radio emission or variation in the observed x-rays due to such phenomena being either nonexistent or difficult to detect. The weaker magnetic fields than most other detected neutron stars means that most of the detected x-rays are due to blackbody radiation. Confirmation that the CCO is associated with the past supernova can be done using the kinematics of the objects and matching them to the age and kinematics of the host SNR.
