Since antiquity, wreaths have symbolized the cycle of life, death, and rebirth. It is fitting then that one of the best places for astronomers to learn more about the stellar lifecycle resembles a giant holiday wreath itself.
The star cluster NGC 602 lies on the outskirts of the Small Magellanic Cloud, which is one of the closest galaxies to the Milky Way, about 200,000 light-years from Earth. The stars in NGC 602 have fewer heavier elements compared to the Sun and most of the rest of the galaxy. Instead, the conditions within NGC 602 mimic those for stars found billions of years ago when the universe was much younger.
This new image combines data from NASA’s Chandra X-ray Observatory with a previously released image from the agency’s James Webb Space Telescope. The dark ring-like outline of the wreath seen in Webb data (represented as orange, yellow, green, and blue) is made up of dense clouds of filled dust.
Meanwhile, X-rays from Chandra (red) show young, massive stars that are illuminating the wreath, sending high-energy light into interstellar space. These X-rays are powered by winds flowing from the young, massive stars that are sprinkled throughout the cluster. The extended cloud in the Chandra data likely comes from the overlapping X-ray glow of thousands of young, low-mass stars in the cluster.
Image credit: X-ray: NASA/CXC; Infrared: ESA/Webb, NASA & CSA, P. Zeilder, E.Sabbi, A. Nota, M. Zamani; Image Processing: NASA/CXC/SAO/L. Frattare and K. Arcand
Image description: A star cluster is shown inside a large nebula of many-colored gas and dust. The material forms dark ridges and peaks of gas and dust surrounding the cluster, lit on the inner side, while layers of diffuse, translucent clouds blanket over them. Around and within the gas, a huge number of distant galaxies can be seen, some quite large, as well as a few stars nearer to us which are very large and bright.
Tags: NGC 602
Even in space, connections are important.
This image of NGC 2566 is part of an observing program dedicated to understanding the connections between stars, gas and dust in nearby star-forming galaxies. Read more: esawebb.org/images/potm2412a/
Image credit: ESA/Webb, NASA & CSA, A. Leroy
Image description: An oval-shaped spiral galaxy, seen close-up. Its core is a compact, pale spot that glows brightly, filling the disc with bluish light. Faint strands of pale reddish dust swirl out from the core to the far sides of the disc. They each join up with an arm of thick, cloudy, red dust with brighter orange patches, that follows the edge of the disc around to the opposite end and a little off the galaxy.
A riddle wrapped in a 20-year-old Hubble mystery…
Webb just confirmed a controversial finding of Hubble’s - there are planet-forming disks in the early universe that are longer-lived than they should be given the conditions in their environment. In 2003, Hubble found evidence of a massive planet in our galaxy from a long-ago time when stars only had small amounts of heavy elements like iron and carbon - the building blocks of planets. How could this planet grow so massive in these conditions?
Webb recently took a look at a star-forming cluster (in the nearby Small Magellanic Cloud) which also has a relative lack of heavier elements, making it a close proxy, with similar conditions, to star clusters in the early universe - like the one Hubble observed in the early Milky Way.
Webb's sensitive instruments can split up light into its components, unlocking the chemical make-up of whatever it is observing, in detail. Webb saw that the stars in cluster NGC 346 do have longer-live disks which allow their planets time to form and grow - despite the lack of heavier elements. And those disks are longer-lived than those seen around young stars in our Milky Way galaxy. How do these disks survive long enough to form massive planets? Maybe it takes longer for stars in clusters with fewer heavier elements to blow away its disk. Maybe the gas clouds that formed these stars are more massive, producing bigger disks that take longer to disperse - or some combination of these things.
Read more: science.nasa.gov/missions/webb/nasas-webb-finds-planet-fo...
Image credit: NASA, ESA, CSA, STScI, Olivia C. Jones (UK ATC), Guido De Marchi (ESTEC), Margaret Meixner (USRA)
Image Description: The center of the image contains arcs of orange and pink that form a boat-like shape. One end of these arcs points to the top right of the image, while the other end point toward the bottom left. Another plume of orange and pink expands from the center to the top left of the image. To the right of this plume is a large cluster of white stars. There are various other white stars and a few galaxies of different sizes spread throughout the image. Ten, small, yellow circles overlaid at various points across the image indicate the positions of the ten stars surveyed in this study.
Tags: jwst webb james webb space telescope planet-forming disks
This graph shows, on the bottom left in yellow, a spectrum of one of the 10 target stars in this study (as well as accompanying light from the immediate background environment). Spectral fingerprints of hot atomic helium, cold molecular hydrogen, and hot atomic hydrogen are highlighted. On the top left in magenta is a spectrum slightly offset from the star that includes only light from the background environment. This second spectrum lacks a spectral line of cold molecular hydrogen.
On the right is the comparison of the top and bottom lines. This comparison shows a large peak in the cold molecular hydrogen coming from the star but not its nebular environment. Also, atomic hydrogen shows a larger peak from the star. This indicates the presence of a protoplanetary disk immediately surrounding the star. The data was taken with the microshutter array on the James Webb Space Telescope's NIRSpec (Near-Infrared Spectrometer) instrument.
Read the full story: science.nasa.gov/missions/webb/nasas-webb-finds-planet-fo...
Credits:
Illustration
NASA, ESA, CSA, Joseph Olmsted (STScI)
Image description: Graphic titled Star in NGC 346, Molecular Hydrogen in Protoplanetary Disk, NIRSpec Microshutter Array Spectroscopy showing brightness of 2.02- to 2.37-micron light of a star and its environment (plotted in yellow) and a star’s environment only (plotted in pink) on an xy graph of brightness versus wavelength in microns. Two wavelength bands, ranging from 2.05 to 2.07 and 2.16 to 2.18, are highlighted in red and labeled Hot Atomic Helium, He. A band from 2.11 to 2.13 in blue is labeled Cold Molecular Hydrogen, H 2. The spectrum of the star plus environment (yellow) has prominent peaks at 2.06 and 2.17 microns (He), and at 2.12 microns (H). The spectrum of the star’s environment only (pink) also has peaks at 2.06 and 2.17 microns (He), but not at 2.12 (H). The two spectra are offset vertically for readability. An inset shows them plotted with the same vertical alignment: the helium peaks on the star plus environment spectrum are slightly taller than those of the environment only.
Tags: jwst webb james webb space telescope planet-forming disks
This side-by-side comparison shows a Hubble image of the massive star cluster NGC 346 (left) versus a Webb image of the same cluster (right). While the Hubble image shows more nebulosity, the Webb image pierces through those clouds to reveal more of the cluster's structure. NGC 346 has a relative lack of elements heavier than helium and hydrogen, making it a good proxy for stellar environments in the early, distant universe.
Read the full story: science.nasa.gov/missions/webb/nasas-webb-finds-planet-fo...
Credits
Image: NASA, ESA, CSA, STScI, Olivia C. Jones (UK ATC), Guido De Marchi (ESTEC), Margaret Meixner (USRA), Antonella Nota (ESA)
Image description: A side-by-side comparison of a Hubble image of the massive star cluster NGC 346 (left) versus a Webb image of the same cluster (right). The Hubble image shows the cluster in shades of blue against a black background punctuated by white stars of various sizes. Ethereal nebulosity, looking much like draped chiffon, dominates the image. The Webb view, in shades of pink and orange against a black background, is speckled with fewer stars than in the Hubble version. These stars are white and pink. Webb pierces through the cluster’s clouds to reveal more of its structure, which looks like twisted fibers.
Tags: jwst webb james webb space telescope planet-forming disks