The joint NASA/European Space Agency/Canadian Space Agency James Webb Space Telescope recently observed the remnants of a dying star shedding its outer layers. The resulting colorful cloud is known as a planetary nebula, and structures in this nebula revealed by Webb hint at the presence of a companion star.
Meanwhile, a team of scientists used the observatory to peer at galaxies in the early universe. With its Mid-Infrared Instrument (MIRI), the telescope provided a new perspective on a patch of sky famously observed by the Hubble Space Telescope for its Hubble Ultra Deep Field image.
NGC 6072 captured by Webb’s Near Infrared Camera instrument. (Credit: NASA, ESA, CSA, STScI)
Vibrant structures in NGC 6072
As a star one to eight times the mass of the Sun nears the end of its life, it expels its outer layers, spewing up to 80% of its mass into space. Left in the center of this cloud of material is the star’s brightly glowing core, also known as a white dwarf. The intense ultraviolet (UV) light emitted by the white dwarf lights up the surrounding material into a colorful nebula.
Confusingly, these clouds are known to astronomers as planetary nebulae, named after their resemblance to faint planets, when observed through small telescopes.
The Space Telescope Science Institute (STScI), which operates Webb, recently released an image of a planetary nebula known as NGC 6072. The nebula is located roughly 3,300 light-years from Earth, in the southern constellation of Scorpius. Webb observed NGC 6072 on July 29, 2024, with its MIRI and Near-InfraRed Camera (NIRCam) instruments.
Webb’s images reveal structures inside the nebula in high detail, showing several flows of material streaming away from the star at the center. These flows might be the result of the aging star interacting with a companion star. The presence of these flows supports a 2021 study that marked NGC 6072 as a candidate for a binary star based on findings from the European Space Agency’s (ESA) Gaia telescope.
NGC 6072 captured by Webb Mid-Infrared Instrument. (Credit: NASA, ESA, CSA, STScI)
Additional evidence is provided by Webb’s mid-infrared image, which shows concentric rings. This pattern was likely formed by the companion star orbiting the dying star that created the nebula.
The same mid-infrared image also shows the white dwarf at the center of the nebula, where it’s visible as a pinkish dot. The secondary star, however, is not visible, and its presence remains unconfirmed but likely.
Over time, the nebula’s material will slowly disperse into the interstellar medium, where it might feed into new stars and planetary systems. Scientists study planetary nebulae like NGC 6072 to learn more about this process. Additionally, these vivid clouds help astronomers gain a better understanding of a Sun-like star’s lifecycle and the processes our own star will go through at the end of its life.
Webb’s take on the Hubble Ultra Deep Field
ESA recently released a so-called deep field image taken by Webb’s MIRI and NIRCam instruments. Telescopes produce these deep fields by observing a certain area for extended periods and by revisiting the area multiple times. The resulting image includes more detail than regular observations, including faint signals from extremely distant galaxies, allowing astronomers to study some of the universe’s oldest galaxies.
Webb’s view of the area from which the Hubble Ultra Deep Field was taken, constructed from observations with NIRCam and MIRI. (Credit: ESA/Webb/NASA/CSA/G. Östlin/P. G. Perez-Gonzalez/J. Melinder/the JADES Collaboration/the MIDIS collaboration/M. Zamani)
Famously, the Hubble Space Telescope took a deep field in the mid-1990s. Pointing at a seemingly empty area of sky, the telescope revealed thousands of distant galaxies, many too faint for ground-based telescopes to observe.
This image sparked subsequent deep field observations on Hubble and other observatories, including the Hubble Ultra Deep Field in the early 2000s. In recent years, Webb has revisited part of this field: an area now known as the MIRI Deep Imaging Survey (MIDIS) region.
The team behind the MIDIS study intended to image the field in six observations — known as visits — in December 2022, but problems with the telescope cut these plans short. While the first four visits were conducted successfully between Dec. 2 and Dec. 6, Webb repeatedly entered safe mode from Dec. 7 onwards. During these safe mode events, the spacecraft shuts off all nonessential systems, including science instruments.
NASA traced the problems to a software fault triggered in the spacecraft’s attitude control system, which it uses for pointing at its observation targets. The telescope fully resumed normal observations on Dec. 20, 2022.
As a result of the pointing issues, one of the observations for the MIDIS deep field was rotated and offset. Moreover, the sixth visit was performed a year later on Dec. 6, 2023, observing in different wavelengths than originally planned. The team plans to analyze that final observation in a different study.
(Video Caption: Comparison between the Webb’s MIDIS deep field and the 2012 Hubble eXtreme Deep Field taken by Hubble of the same region in the original Hubble Ultra Deep Field.)
The observations performed in 2022 took over 41 hours in total exposure time. Their combined images revealed approximately 2,500 objects. Most of these are distant galaxies, although some are likely artifacts from cosmic rays that weren’t filtered out correctly.
With deep field studies like these, scientists want to find some of the earliest galaxies and better understand when galaxies formed and how they evolved over time. The deep fields help astronomers figure out how the universe went from having little structure in its early days to having stars, galaxies, black holes, and other structures.
The team has since revisited the field with Webb in early December 2024, observing it in two different wavelengths, 7.7 micrometers (μm) and 10 μm, compared to the 5.6 μm signal studied in 2022. The recently-released image combines all of these observations with some taken earlier by NIRCam, totaling nearly 100 hours of exposure time. More observations are planned for late November and early December of this year.
(Lead image: NGC 6072 as imaged by Webb (left) and Webb’s view on the Hubble Ultra Deep Field (right). Credit: NASA, ESA, CSA, STScI (left), ESA/Webb, NASA & CSA, G. Östlin, P. G. Perez-Gonzalez, J. Melinder, the JADES Collaboration, the MIDIS collaboration, M. Zamani (right))
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