ESO has released images of the stellar nursery cataloged as RCW 38, obtained using the VISTA InfraRed CAMera (VIRCAM) mounted on its Visible and Infrared Survey Telescope for Astronomy (VISTA) in Chile. It was obtained as part of the VISTA Variables in the Vía Láctea (VVV) astronomical survey, which produced the most detailed infrared map of the Milky Way. The infrared observations allow to see the electromagnetic emissions generated by young stars and protostars within RCW 38, which can pass through the blanket of gas and dust that blocks almost all other electromagnetic bands.
Located about 5,500 light-years from Earth, the star cluster RCW 38
is considered very interesting by astronomers because it’s estimated to contain about 2,000 young stars and protostars. There’s considerable activity inside it and astronomers want to observe it to gain new insights into the star formation processes taking place.
The problem for astronomers is that stellar nurseries such as RCW 38 are filled with gas and dust that block most electromagnetic frequencies. Infrareds are among the few emissions that pass through that blanket, which is why instruments that can detect them are essential for this type of study.
VISTA enabled observations of the RCW 38 star cluster to be obtained in extraordinary detail. Stars and protostars were seen still in their cocoons. Many of those stars are much more massive than the Sun, but there are also brown dwarfs, objects halfway between stars and planets that are difficult to observe due to their very weak emissions.
Massive stars and protostars emit intense radiation that hits the surrounding gas and makes it shine. The contrast with other areas where gas and dust are cooler creates the differences in color within the RCW 38 cluster. This characteristic of stellar nurseries also ensures the creation of spectacular photographs.
This is not the first time that ESO instruments have observed the RCW 38 cluster and it certainly will not be the last. The VIRCAM camera was decommissioned after several years of honorable and fruitful service and will be replaced in 2025 by a new, more advanced instrument called the 4-metre Multi-Object Spectrograph Telescope (4MOST), which will be able to provide new astronomical information. Instruments from other institutions will also be used to study stellar nurseries such as RCW 38 to obtain further details of the star formation processes and breathtaking images.
