Within the Milky Way’s outskirts is a firecracker show of star formation. The NASA/ESA/CSA James Webb Space Telescope has examined the fringes of our Milky Way galaxy and Webb’s near- and mid-infrared imaging capabilities have enabled scientists to examine a star-forming area reminiscent of our galaxy during its early stages of formation.
Astronomers have directed the NASA/ESA/CSA James Webb Space Telescope to examine the outskirts of our Milky Way galaxy, a region scientists call the Extreme Outer Galaxy owing to its location more than 58 000 light-years away from the Galactic centre. For comparison, Earth is approximately 26 000 light-years from the centre.
A team of scientists used Webb’s NIRCam (Near-Infrared Camera) and MIRI (Mid-Infrared Instrument) to image selected regions within two molecular clouds known as Digel Clouds 1 and 2. Thanks to its high sensitivity and sharp resolution, Webb was able to resolve these areas, which are hosts to star clusters undergoing bursts of star formation, in unprecedented detail. Some of the details revealed by these data include components of the clusters such as very young (Class 0) protostars, outflows and jets, and distinctive nebular structures.
These Webb observations are enabling scientists to study star formation in the outer Milky Way at the same level of detail as observations of star formation in our own solar neighbourhood.
Stars in the making
Although the Digel Clouds are within our galaxy, they are relatively poor in elements heavier than hydrogen and helium. This composition makes them similar to dwarf galaxies and our own Milky Way in its early history. The team therefore took the opportunity to use Webb to capture the activity in four clusters of young stars within Digel Clouds 1 and 2: 1A, 1B, 2N, and 2S.
In Cloud 2S, Webb captured the main cluster containing young, newly formed stars. This dense area is quite active and several stars are emitting extended jets of material along their poles. Additionally, while scientists previously suspected a sub-cluster might be present within the cloud, Webb’s imaging capabilities confirmed its existence for the first time. Webb’s data reveal that there are multiple jets shooting out in different directions from this cluster of stars.
The saga of stars
This Webb imagery of the Extreme Outer Galaxy and the Digel Clouds is just a starting point for the team. They intend to revisit this Milky Way outpost to find answers to a variety of current questions, including the relative abundance of stars of various masses within Extreme Outer Galaxy star clusters, a measurement that would help astronomers understand how a particular environment can influence different types of stars during their formation.
Though the story of star formation is complex and some chapters are still shrouded in mystery, Webb is gathering clues and helping astronomers unravel this intricate tale.
These findings have been published in the Astronomical Journal.
The observations were taken as part of Guaranteed Time Observation program 1237.
Digel Cloud 2S
The NASA/ESA/CSA James Webb Space Telescope has observed the very outskirts of our Milky Way galaxy. Known as the Extreme Outer Galaxy, this region is located more than 58 000 light-years from the Galactic centre.
To learn more about how a local environment affects the star formation process within it, a team of scientists directed the telescope’s NIRCam (Near-InfraRed Camera) and MIRI (Mid-InfraRed Instrument) towards a total of four star-forming areas within Digel Clouds 1 and 2: 1A, 1B, 2N, and 2S.
In the case of Cloud 2S, shown here, Webb revealed a luminous main cluster that contains newly formed stars. Several of these young stars are emitting extended jets of material from their poles. To the main cluster’s top right is a sub-cluster of stars, a feature that scientists previously suspected to exist but has now been confirmed with Webb. Additionally, the telescope revealed a deep sea of background galaxies and red nebulous structures that are being carved away by winds and radiation from nearby stars.
[Image description: At centre is a compact star cluster composed of luminous red, blue, and white points of light. Faint jets with clumpy, diffuse material extend in various directions from the bright cluster. Above and to the right is a smaller cluster of stars. Translucent red wisps of material stretch across the scene, though there are patches and a noticeable gap in the top left corner that reveal the black background of space. Background galaxies are scattered across this swath of space, appearing as small blue-white and orange-white dots or fuzzy, thin discs. There is one noticeably larger blue-white point with diffraction spikes, a foreground star in the upper right.]
Credit:
NASA, ESA, CSA, STScI, M. Ressler (NASA-JPL)
Digel Cloud 2S (annotated)
Annotated image of Digel Cloud 2S captured by Webb's NIRCam (Near-Infrared Camera) and MIRI (Mid-Infrared Instrument), with compass arrows, a scale bar, colour key, and graphic overlays for reference.
The north and east compass arrows show the orientation of the image on the sky. Note that the relationship between north and east on the sky (as seen from below) is flipped relative to direction arrows on a map of the ground (as seen from above).
The scale bar is labelled in light-years and arcseconds. One light-year is equal to about 9.46 trillion kilometres. One arcsecond is equal to 1/3600 of one degree of arc (the full Moon has an angular diameter of about 0.5 degrees). The actual size of an object that covers one arcsecond on the sky depends on its distance from the telescope.
This image shows invisible near- and mid-infrared wavelengths of light that have been translated into visible-light colours. The colour key shows which NIRCam and MIRI filters were used when collecting the light. The colour of each filter name is the visible light colour used to represent the infrared light that passes through that filter.
In the main cluster are five white arrows, which highlight the paths of five protostar jets.
Credit:
NASA, ESA, CSA, STScI, M. Ressler (NASA-JPL)
VIDEO
Pan of Digel Cloud 2S
The NASA/ESA/CSA James Webb Space Telescope has observed the outskirts of our Milky Way galaxy. Known as the Extreme Outer Galaxy, this region is located more than 58 000 light-years from the Galactic centre.
To learn more about how a local environment affects the star formation process within it, a team of scientists directed the telescope’s NIRCam (Near-InfraRed Camera) and MIRI (Mid-InfraRed Instrument) toward a total of four star-forming areas within Digel Clouds 1 and 2: 1A, 1B, 2N, and 2S.
In the case of Cloud 2S, shown here, Webb revealed a luminous main cluster that contains newly formed stars. Several of these young stars are emitting extended jets of material from their poles. To the main cluster’s top right is a sub-cluster of stars, a feature that scientists previously suspected to exist but has now been confirmed with Webb. Additionally, the telescope revealed a deep sea of background galaxies and red nebulous structures that are being carved away by winds and radiation from nearby stars.
Credit:
NASA, ESA, CSA, STScI, M. Ressler (NASA-JPL), N. Bartmann (ESA/Webb)
Music: Stellardrone - Twilight
Fuente: ESA/Hubble/Webb Information Centre
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