RCW 7 is located approximately 5,300 light-years away from Earth in the constellation of Puppis.
This Hubble image shows the nebula RCW 7. Image credit: NASA / ESA / Hubble / J. Tan, Chalmers University & University of Virginia.
“Nebulae are areas of space that are rich in the raw material needed to form new stars,” Hubble astronomers said.
“Under the influence of gravity, parts of these molecular clouds collapse until they coalesce into protostars, surrounded by spinning disks of leftover gas and dust.”
“In the case of RCW 7, the protostars forming here are particularly massive, giving off strongly ionizing radiation and fierce stellar winds that have transformed it into what is known as a H II region.”
“H II regions are filled with hydrogen ions — where H I refers to a normal hydrogen atom, H II is hydrogen that has lost its electron.”
“The ultraviolet radiation from the massive protostars excites the hydrogen, causing it to emit light and giving this nebula its soft pinkish glow.”
In RCW 7, the researchers focused on a massive pair of protostars named IRAS 07299-1651.
“IRAS 07299-1651 is still in its glowing cocoon of gas in the curling clouds towards the top of the nebula,” they said.
To expose this star and its siblings, the new image was made from separate exposures taken in the near-infrared region of the spectrum with Hubble’s Wide Field Camera 3 (WFC3).
“The massive protostars here are brightest in ultraviolet light, but they emit plenty of infrared light which can pass through much of the gas and dust around them and be seen by Hubble,” the scientists said.
“Many of the other, larger-looking stars in this image are not part of the nebula, but sit between it and our Solar System.”
IRAS 07299-1651 is estimated to have a minimum total mass of 18 solar masses and a maximum period of 570 years, assuming a circular orbit.
“The creation of an H II region marks the beginning of the end for a molecular cloud,” the authors said.
“Over only a few million years, the radiation and winds from the massive stars gradually disperse the gas — even more so as the most massive stars come to the end of their lives in supernova explosions.”
“Only a fraction of the gas will be incorporated into new stars in this nebula, with the rest being spread throughout the galaxy to eventually form new molecular clouds.”
The team’s findings appear in the journal Nature Astronomy.
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Y. Zhang et al. 2024. Dynamics of a massive binary at birth. Nat Astron 3, 517-523; doi: 10.1038/s41550-019-0718-y
Source : Breaking Science News