In celebration of the 25th anniversary of the International Gemini Observatory’s completion, students in Chile chose the Gemini South Telescope to capture an image of NGC 6302, also known as the Bug Nebula or Butterfly Nebula (Caldwell 69).
This image captured by the Gemini South Telescope showcases the planetary nebula NGC 6302. Image credit: International Gemini Observatory / NOIRLab / NSF / AURA / J. Miller & M. Rodriguez, International Gemini Observatory & NSF’s NOIRLab / TA Rector, University of Alaska Anchorage & NSF’s NOIRLab / M. Zamani, NSF’s NOIRLab.
NGC 6302 is a planetary nebula situated 2,417 light-years away in the constellation Scorpius.
“Planetary nebulae are a type of emission nebula formed by a massive star at the end of its lifecycle, shedding material and surrounded by an expanding, glowing shell of ionized gas,” stated astronomers at the International Gemini Observatory.
“These intriguing structures usually have a circular, planet-like appearance, which is how they earned the name ‘planetary nebulae’ from early astronomers who observed them through telescopes.”
While various dates are associated with the discovery of NGC 6302, a 1907 study by American astronomer Edward E. Barnard is commonly credited, though it could have been discovered earlier in 1826 by Scottish astronomer James Dunlop.
This nebula is characterized by an extremely complex dipolar morphology, highly excited gases, elevated molecular weight, and the presence of crystalline silicate dust.
Its butterfly shape extends over two light-years, roughly half the distance from the Sun to Proxima Centauri.
“In recent images obtained from the Gemini South Telescope, the glowing ‘wings’ of the Butterfly Nebula appear to emerge from the interstellar medium,” the astronomers explained.
“This visually stunning object was chosen by Chilean students for the 8.1-meter telescope as part of the Gemini First Light Anniversary Image Contest.”
“This competition engaged students at the Gemini telescope site, honoring the legacy established by the International Gemini Observatory since its first light in November 2000.”
In 2009, astronomers utilized the Wide Field Camera 3 on the NASA/ESA Hubble Space Telescope to identify the central star of NGC 6302 as a white dwarf. This star shed its outer layers over 2,000 years ago and now possesses about two-thirds the mass of the Sun.
It ranks as one of the hottest known stars, with a surface temperature exceeding 250,000 degrees Celsius (450,000 degrees Fahrenheit), indicating it must have formed from a substantially large star.
Further investigation of NGC 6302 uncovers a dramatic formation history.
Before its transformation into a white dwarf, the star was a red giant approximately 1,000 times the diameter of the Sun.
This massive star expelled its outer gas layer, moving outward from the equator at a relatively slow rate, forming a dark donut-shaped band still observable around the star.
Other gases were expelled perpendicular to this band, restricting outflow and creating the bipolar structure visible today.
As the star evolved, it released strong stellar winds that pierced its “wings” at speeds exceeding 3 million kilometers per hour (1.8 million miles per hour).
This combination of slow and fast-moving gases further sculpted the “wings,” revealing a vast terrain of cloudy ridges and pillars.
Now, as a white dwarf, the star emits intense radiation that elevates the temperature of NGC 6302’s “wings” to over 20,000 degrees Celsius (approximately 35,000 degrees Fahrenheit), causing the gas to glow.
“Dark red areas in the image represent regions of energized hydrogen gas, while deep blue spots indicate regions of energized oxygen gas,” the researchers mentioned.
“These materials, alongside other elements like nitrogen, sulfur, and iron discovered in NGC 6302, are critical for forming the next generation of stars and planets.”
Source: www.sci.news
