Astronomers at ESO’s La Silla Observatory in Chile have released a stunning new image of the Pencil Nebula, a small part of a supernova remnant in the southern constellation of Vela.
This image shows the oddly shaped Pencil Nebula, a small part of a huge remnant left over after a supernova explosion that took place about 11 000 years ago (ESO)
This new image from the Wide Field Imager on the MPG/ESO 2.2-m telescope shows the Pencil Nebula against a rich starry background.
The nebula, which is also known as NGC 2736, is part of a huge ring of wreckage left over after a supernova explosion that took place about 11 000 years ago. The brightest part resembles a pencil; hence the name, but the whole structure looks rather more like a traditional witch’s broom.
The Vela supernova remnant is an expanding shell of gas that originated from the supernova explosion. Initially the shock wave was moving at millions of kilometers per hour, but as it expanded through space it ploughed through the gas between the stars, which has slowed it considerably and created strangely shaped folds of nebulosity. The Pencil Nebula is the brightest part of this huge shell.
This new image shows large, wispy filamentary structures, smaller bright knots of gas and patches of diffuse gas. The nebula’s luminous appearance comes from dense gas regions that have been struck by the supernova shock wave. As the shock wave travels through space, it rams into the interstellar material. At first, the gas was heated to millions of degrees, but it then subsequently cooled down and is still giving off the faint glow that was captured in the new image.
By looking at the different colors of the Pencil Nebula, astronomers have been able to map the temperature of the gas. Some regions are still so hot that the emission is dominated by ionized oxygen atoms, which glow blue in the picture. Other cooler regions are seen glowing red, due to emission from hydrogen.
The nebula measures about 0.75 light-years across and is moving through the interstellar medium at about 650 000 kilometers per hour. Remarkably, even at its distance of approximately 800 light-years from Earth, this means that it will noticeably change its position relative to the background stars within a human lifetime.
