The Remnant of Supernova 1987A
This image shows the remnant of Supernova 1987A, 168,000 light years distant in the outskirts of the Tarantula Nebula in the Large Magellanic Cloud.
This target is extremely small, and I was surprised to even be able to see anything in the image at all. To achieve the highest possible resolution I cropped and up-sampled each frame 6x, and then stacked all together using Registax. The result shows a significantly higher resolution than the original prime focus image.
The structure of the remnant is of course not resolved due to its extremely small size (the radius of the inner ring visible in the HST image is only 0.8 arc seconds). However, a distinct patch of pink nebulosity is visible at the expected position.
The light from the supernova reached Earth on February 23, 1987. Its brightness peaked in May with an apparent magnitude of about 3 and slowly declined in the following months. SN1987A appears to be a core-collapse supernova, and the progenitor star itself was identified as Sanduleak -69° 202a, a Luminous Blue Variable (LBV). This class of stars is known for ejecting large amounts of mass in sporadic, violent outbursts.
The rings in the HST image are the results of such previous violent mass ejections from the unstable star. These rings were ionized and made visible by the supernova flash. The material from the explosion is now also catching up with and heating this material, and thus causing continuous development in the ring structures around the star.
Some three hours before the visible light from SN1987A reached Earth, a burst of neutrinos was observed at three separate neutrino observatories. This is due to the fact that the emission of visible light occurs only after the shock wave reaches the stellar surface. When the core collapsed, the in falling material rebounded and caused a shock wave to pass through the star. This shock wave reached the surface a few hours later, travelling at the local speed of sound inside the star. This was the first time neutrinos emitted from a supernova had been observed directly, and the observations were consistent with theoretical supernova models in which 99% of the energy of the collapse is radiated away in neutrinos. Several other LBV stars, including Eta Carinae, might join the fate of Sandulaek -69° 202a in the next few thousand years.
153 x 15s taken on 27/11/2010 with 10" Newtonian f/5 and ToUCam Pro SC1.
No filters, no guiding.