Second James Webb image of Ring Nebula hints at dying star’s companion

The image, from James Webb’s MIRI (Mid-Infrared Instrument) (on the right of the main image above), complements an image issued earlier this month, showing the Ring Nebula at shorter wavelengths of infrared light, taken by James Webb’s NIRCam (Near Infrared Camera) (above left).

The Ring Nebula, located about 2,600 light years away in the constellation Lyra, formed when a dying star ejected its outer layers about 4,000 years ago (the same fate eventually awaits our Sun). The two images show its intricate structures - its rings, bubbles and wispy clouds - in exquisite, unprecedented detail.

The main ring of the nebula is made up of 20,000 clumps of dense molecular hydrogen gas, each about the mass of the Earth, all immersed in hot ionized gas. The inner region is made up mainly of this hot gas. The main shell also contains a thin ring of enhanced emission from carbon-based molecules known as polycyclic aromatic hydrocarbons (PAHs).

The MIRI image reveals, for the first time, 10 or so concentric arcs located just beyond the outer edge of the main ring. These arcs must have formed about every 280 years.

No known process involved in the evolution of a star into a nebula has that kind of time period, so it is believed the arcs have formed from the interaction of the dying red giant star with a companion star located the same distance away from it as Pluto is from the Sun.

Professor Mike Barlow (UCL Physics & Astronomy), lead scientist of the James Webb Space Telescope Ring Nebula Project, said: “This striking image from James Webb’s MIRI reveals new details that we could not observe with the NIRCam – notably the arcs beyond the main ring.

“These formed in the central star’s red giant phase, before it threw off most of its material to become the current hot white dwarf star. Early analysis by our team suggests a low-mass companion star with an eccentric orbit triggered an enhanced release of material from the dying star as it passed close by every 280 years, creating these arcs.”

Dr Roger Wesson, of Cardiff University, said: “Our MIRI images provided us with the sharpest and clearest view yet of the faint molecular halo outside the bright ring. A surprising revelation was the presence of up to ten regularly spaced, concentric features within this faint halo. No previous telescope had the sensitivity and the spatial resolution to uncover this subtle effect.” 

The colours in the two images represent infrared (invisible) light of different wavelengths emitted by the nebula’s chemical elements and by warm dust particles. By analysing the images, researchers hope to understand better the complex processes behind the formation and evolution of such objects.

The Ring Nebula is one of the most notable objects in our skies. It was discovered in 1779 by astronomers Charles Messier and Antoine Darquier de Pellepoix. Both astronomers stumbled upon the nebula when trying to follow the path of a comet through the constellation of Lyra.

The Ring Nebula is known as a “planetary nebula” because early astronomers thought such nebulae looked like planets.

The international research team analysing these images involves researchers from the UK, France, Canada, USA, Sweden, Spain, Brazil, Ireland and Belgium. The James Webb Space Telescope is an international partnership between NASA, ESA and the Canadian Space Agency (CSA).

Links

• ESA’s story
• NASA blog
• Professor Mike Barlow’s academic profile
• UCL Physics & Astronomy
• UCL Mathematical & Physical Sciences
• MIRI – Mid-Infrared Instrument

Image

• Top: This visual shows two images side by side of the Ring Nebula. The image on the left shows Webb’s NIRCam view and the image on the right shows Webb’s MIRI image. The left image shows the planetary nebula as a distorted donut with a rainbow of colours with a blue/green inner cavity and clear filamental structure in the inner region of the ring. The right image shows the nebula with a red/orange central cavity with a ring structure that transitions from colours of yellow to purple/blue. Credit: ESA/Webb, NASA, CSA, M. Barlow, N. Cox, R. Wesson
• Middle: This image of the Ring Nebula (from MIRI) appears as a distorted doughnut. The nebula’s inner cavity hosts shades of red and orange, while the detailed ring transitions through shades of yellow in the inner regions and blue/purple in the outer region. The ring’s inner region has distinct filament elements. Credit: ESA/Webb, NASA, CSA, M. Barlow, N. Cox, R. Wesson

Media contact

Mark Greaves

E: m.greaves [at] ucl.ac.uk