To celebrate the 25th anniversary of the completion of the Gemini International Observatory, students in Chile voted for the Gemini South Telescope to image the Butterfly Nebula, which is also known as NGC 6302, the Bug Nebula, or Caldwell 69.
This Gemini South image shows the planetary nebula NGC 6302. Image credit: Gemini International Observatory / NOIRLab / NSF / AURA / J. Miller and M. Rodriguez, Gemini International Observatory and NSF NOIRLab / TA Rector, University of Alaska Anchorage and NSF NOIRLab / M. Zamani, NOIRLab NSF.
NGK 6302 is a planetary nebula located 2417 light years away in the constellation Scorpio.
“A planetary nebula is a type of emission nebula consisting of a massive star nearing the end of its life that ejects material, surrounded by an expanding, luminous envelope of ionized gas,” astronomers from Gemini International Observatory said in a statement.
“Typically, these fascinating structures are round in shape, similar to a planet, so the first astronomers who observed them with telescopes called them “planetary nebulae.”
Sources give varying dates for the discovery of NGC 630, but credit usually goes to American astronomer Edward E. Barnard's 1907 study, although Scottish astronomer James Dunlop may have discovered it in 1826.
Nebula show extreme bipolarity, complex morphology, presence of very high pathogen gas, high molecular weight and crystalline silicate dust.
Its butterfly shape stretches over two light years, which is approximately half the distance from the Sun to Proxima Centauri.
“In a new image from the Gemini South telescope, the glowing 'wings' of the Butterfly Nebula emerge from the interstellar medium,” the astronomers said.
“This picturesque object was chosen as the target for the 8.1-meter telescope by students in Chile as part of an image competition to celebrate Gemini's first bright anniversary.”
“The competition brought together students from across the Gemini telescopes to celebrate the legacy that Gemini International Observatory has created since its completion with the first light of Gemini South in November 2000.”
In 2009, astronomers used Wide Field Camera 3 aboard the NASA/ESA Hubble Space Telescope to identify the central star of NGC 6302 as a white dwarf that ejected its outer layers more than 2,000 years ago and now accounts for about two-thirds of the mass of our Sun.
It is one of the hottest stars known, with surface temperatures exceeding 250,000 degrees Celsius (450,000 degrees Fahrenheit), meaning the star from which it formed must have been very large.
Further studies of NGC 6302 revealed a dramatic formation history.
Before becoming a white dwarf, the star was a red giant with a diameter about 1,000 times the diameter of the Sun.
The massive star shed its outer layers of gas, which moved away from the equator at a relatively slow speed, creating a dark donut-shaped streak still visible around the star.
Other gas was ejected perpendicular to the strip, limiting the outflow and creating the bipolar structure seen today.
As the star continued to evolve, it released a powerful gust of stellar wind that tore through the wings at speeds of more than 3 million kilometers per hour (1.8 million mph).
The interaction between slow and fast moving gas further transformed the “wings” into vast landscapes of cloud ridges and pillars.
Now a white dwarf, the star emits intense radiation that heats NGC 6302's “wings” to more than 20,000 degrees Celsius (about 35,000 degrees Fahrenheit) and causes the gas to glow.
“The rich red color in the image indicates regions with active hydrogen gas, while the bright blue color indicates regions with active oxygen gas,” the researchers said.
“This material, in addition to other elements scientists discovered in NGC 6302 such as nitrogen, sulfur and iron, will contribute to the formation of the next generation of stars and planets.”
