RCW 34 (Gum 19) -

H II region An H II region is a region of interstellar atomic hydrogen that is ionized. It is typically in a molecular cloud of partially ionized gas in which star formation has recently taken place, with a size ranging from one to hundreds of light year ...

and the

emission nebula An emission nebula is a nebula formed of ionized gases that emit light of various wavelengths. The most common source of ionization is high-energy ultraviolet photons emitted from a nearby hot star. Among the several different types of emission n ...

located in the constellation Vela. It is located approximately 8,200

light years A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by the International Astro ...

from

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

. Named after Australian astronomer Colin Stanley Gum. The nebula RCW 34 is relatively dark. However, when observed using

infrared Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those ...

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 A blue supergiant (BSG) is a hot, luminous star, often referred to as an OB supergiant. They are usually considered to be those with luminosity class I and spectral class B9 or earlier, although sometimes A-class supergiants are also deemed blue ...

, 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 A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes systematically with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are ...

, 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

supernova A supernova (: supernovae or supernovas) is a powerful and luminous explosion of a star. A supernova occurs during the last stellar evolution, evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion ...

e. It can be expected that the explosion of the central star will completely change the RCW 34 nebula.

References

{{DEFAULTSORT:RCW 34 Vela (constellation) Emission nebulae H II regions