Astronomers Reveal Ring Nebula’s True 3D Shape as Ellipsoid

A team of astronomers utilizing the Smithsonian Submillimeter Array on Mauna Kea has unveiled the three-dimensional structure of the Ring Nebula, one of the most celebrated objects in the night sky. Through advanced radio-wavelength mapping of carbon monoxide gas emissions, researchers determined that the nebula has an ellipsoidal shape, challenging previous theories that suggested a simple ring or soap bubble structure.

New Insights from Radio-Wavelength Mapping

The research team focused on carbon monoxide (CO) emissions, which provide crucial insights into the molecular gas enveloping the hot gas and dust visible in images captured by the Hubble Space Telescope and the James Webb Space Telescope. According to Joel Kastner, a professor at the Rochester Institute of Technology and the project lead, the ellipsoidal structure became apparent through the data analysis, allowing for the creation of a straightforward geometrical model.

“Now, we understand the structure of this nebula,” Kastner stated. “The SMA allows us to accurately measure the velocities of the molecular gas in the nebula, so we can see what’s moving toward or away from us.”

This new understanding reveals that approximately 6,000 years have passed since the dying star, previously a red giant, expelled the molecular gas that now defines the nebula’s appearance. The study also highlights the influence of a companion star, evident through high-velocity gas blobs that seem to have emerged from either side of the ellipsoidal shell.

Implications for Astronomical Observations

The findings emphasize the importance of using multiple observational techniques to gain a fuller understanding of celestial objects. The Smithsonian Submillimeter Array enabled astronomers to detect specific velocities and locations of carbon dioxide molecules ejected by the dying star, information that cannot be inferred solely from optical images. This breakthrough enhances our comprehension of the Ring Nebula’s complex structure and dynamics.

For those interested in astronomical events, several significant occurrences are approaching. On September 21, Saturn will reach its closest approach to Earth, appearing fully illuminated and visible throughout the night. This will be an ideal opportunity for stargazers to observe Saturn’s rings and its brightest moons through a medium-sized or larger telescope.

The September equinox on September 22 marks the first day of fall in the Northern Hemisphere, when the sun shines directly on the equator, leading to nearly equal day and night across the globe. Following this, on September 23, Neptune will also be at its closest approach to Earth, fully illuminated by the sun, although its extreme distance necessitates the use of powerful telescopes for observation.

For those keen on evening stargazing, at 20:00, the star line Manaiakalani will dominate the night sky, while the constellation Ka‘iwikuamo‘o will set in the western horizon. Early risers can catch the star line Kekaomakali‘i at 05:00, featuring Sirius, the brightest star in the night sky.

The ‘Imiloa Astronomy Center of Hawaii, located at the University of Hawaii at Hilo, serves as a hub for informal science education, showcasing the intertwined journeys of astronomy and Hawaiian culture, offering a unique perspective on human exploration.