IMAGE RELEASE: New Look at a Bright Stellar Nursery (Astronomy)

This overlay shows radio (orange) and infrared images of a giant molecular cloud called W49A, where new stars are being formed. A team of astronomers led by Chris DePree of Agnes Scott College used the National Science Foundation’s Karl G. Jansky Very Large Array (VLA) to make new, high-resolution radio images of this cluster of still-forming, massive stars. W49A, 36,000 light-years from Earth, has been studied for many decades, and the new radio images revealed some tantalizing changes that have occurred since an earlier set of VLA observations in 1994 and 1995.

High-resolution VLA radio image of W49A molecular cloud, with closeups of individual regions where hydrogen gas is ionized by intense ultraviolet radiation from young stars. Credit: DePree, et al.; Sophia Dagnello, NRAO/AUI/NSF

The VLA radio images show the shape and movement of giant clouds of ionized hydrogen gas formed by the intense ultraviolet radiation from young stars. Comparing old and new VLA images of these ionized regions has shown changes indicating new activity in some of the regions. This new activity includes a narrow, fast-moving jet in one region, supersonic gas motions in three others, and an unexpected reduction in the radio brightness in another.

The astronomers, who reported their findings in the Astronomical Journal, plan to continue observing this region regularly to track changes that will reveal new details about the complex processes of star formation and interactions of the outflows from young stars.

The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Featured image: Radio-infrared overlay of W49A molecular cloud. Credit: DePree, et al.; Sophia Dagnello, NRAO/AUI/NSF; Spitzer/NASA.


Reference: C. G. De Pree, D. J. Wilner et al., “Time-variable Radio Recombination Line Emission in W49A”, The Astronomical Journal, 160(5), 2021. https://iopscience.iop.org/article/10.3847/1538-3881/abba27


Provided by National Radio Astronomy Observatory

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