The nebula RCW 34 is relatively dark. However, when observed using infrared wavelengths, two different areas are visible - one half of the nebula is bright, and the other is dark. The bright side is the hydrogen illuminated by a nearby blue supergiant star, and dark is the place where new stars surround the central star on the other side.
The source of energy that stimulates the nebula RCW 34 to shine is a huge, extremely hot star V391 Velorum with a surface temperature of up to 30,000 °C. Because it is a variable star, it evokes violent phenomena, including discards of matter shells, affecting the composition and light emission of the RCW 34 nebula. Stars of the type V391 Velorum do not burn long enough to explode as supernovae. It can be expected that the explosion of the central star will completely change the RCW 34 nebula.
^Bik, A.; Puga, E.; Waters, L.B.F.M.; Horrobin, M.; Henning, Th.; Vasyunina, T.; Beuther, H.; Linz, H.; Kaper, L.; Van Den Ancker, M.; Lenorzer, A.; Churchwell, E.; Kurtz, S.; Kouwenhoven, M. B. N.; Stolte, A.; De Koter, A.; Thi, W. F.; Comerón, F.; Waelkens, Ch. (2010). "Sequential Star Formation in RCW 34: A Spectroscopic Census of the Stellar Content of High-Mass Star-Forming Regions". The Astrophysical Journal. 713 (2): 883–899. arXiv:1002.2571. Bibcode:2010ApJ...713..883B. doi:10.1088/0004-637X/713/2/883. S2CID12429068.