While this starry vista seems tranquil, the events that shaped the Pencil Nebula were nothing but quiet. Stars are born and stars die and when they do, they create amazing stellar landscapes. A star, perhaps a massive one, exploded to sculpt this beautiful starry scene that resembles an exotic bird head or a strangely shaped ray of light.
Explore the fine filaments, bright knots, and nebulous remnants of the Pencil Nebula; just a tiny piece of the Vela Supernova remnant. What shapes or stories do you see? Leave a note in the comments below.
The oddly shaped nebula, also known as NGC 2736, makes up the bright edge of this piece of the remnant. The wispy red filaments look much like a witch’s broom. The new image from the Wide Field Imager on the MPG/ESO 2.2-meter telescope at ESO’s La Silla Observatory in Chile. These glowing wisps of gas and dust are the result of the cataclysmic death of a star more than 11,000 years ago.
A supernova is a violent end to a star’s life. The blast is the result of either the death of a high-mass star or explosion of a white dwarf in a close double star system. The Vela supernova remnant is a vast expanding shell of gas. And as this shell expands it slams into the calm gas and dust surrounding it. This shockwave compresses the gas and causes the nebulae begin to glow. Those little filaments show the many shokwaves moving through the area. At first, as gas molecules are squished together, these regions are heated to millions of degrees but quickly cool as the shockwave passes. Enough lingering heat remains for observers on Earth to view the strange structures created from the shockwave’s interaction with the calm surrounding cloud.
Different colors within the nebula allow astronomers to map temperatures within the cloud of gas. Some regions glow hotly and are dominated by ionized oxygen atoms. These areas show with a blue light. Redder areas are cooler ionized hydrogen clouds.
The Pencil Nebula was discovered by British astronomer John Herschel in 1835. He described it as “an extraordinary long narrow ray of excessively feeble light.” The nebula is also called Herschel’s Ray. The ray of light is about three-quarters of a light year across. The nebula is rolling through the surrounding nebula at about 650,000 kilometers per hour (about 404,000 miles per hour). The Pencil Nebula is close too, only about 800 light-years from Earth toward the constellation of Vela, the sails of Jason’s mythical ship the Argo. This means that over the span of a human life, the starry face of the Pencil Nebula change as it moves against the background of stars.
A stellar shockwave from a supernova 11,000 years ago forms a line in space reminding many observers on Earth of a pencil.
The Pencil Nebula, or NGC 2736, is part of the huge Vela supernova remnant. Located in the southern constellation Vela, this part of the supernova encountered denser gas. The gas from the supernova moves very fast. The Vela supernova blasted material into space at 22 million miles an hour. When it rams into a quiet and dark dust cloud, the gas is heated to millions of degrees. In this image from NASA‘s Hubble Space Telescope, the squeezing of gas and dust in a small area causes the gas to glow with reds, blues and greens. Over time, the speed of the gas moving out slows down. Explore the strands and moving filaments of the Pencil Nebula. Currently, those glowing strands of gas are moving through space at about 400,000 miles an hour; more than one-and-half times the distance between the Earth and the Moon.
British astronomer Sir John Herschel discovered the Pencil Nebula in the 1840s. The Vela Supernova that produced the Pencil Nebula happened long before that. Although there are no records that humans saw the blast 11,000 years ago as the last glacial period was ending, there can be no doubt that it was noticed. The Vela supernova would have shined 250 times brighter than Venus and would have been visible even during the day. The entire Vela supernova remnant stretches across 114 light years and is only 815 light-years from Earth.