RCW 114 (SNR G343.0-06.0)

In 2015, during a stay at the Tivoli Astrofarm in Namibia, I imaged the large supernova remnant RCW 114 using a 105 mm telephoto lens and a CCD camera. I recorded the object in HRGB, combining deep Hα exposures with broadband RGB data to reveal the vast network of faint emission filaments. The exceptionally dark skies of the Namib Desert were essential for capturing this enormous and extremely low-surface-brightness object, which spans several degrees across the sky.

RCW 114 is located in the constellation Scorpius and is identified with the supernova remnant SNR G343.0−06.0. Unlike the bright remnants of more recent stellar explosions, RCW 114 is thought to be several hundred thousand years old. Over this long period, the expanding shock wave has slowed considerably and the remnant has become extremely diffuse, making it a challenging target for deep wide-field astrophotography.

The nebula consists of an intricate web of filamentary hydrogen emission, produced where the expanding shock front compresses and heats the surrounding interstellar medium. The deep Hα data clearly reveal these delicate filaments, while the RGB data preserve the rich foreground star field of the Milky Way. Together, they create a detailed portrait of the remnant’s enormous extent and complex structure.

For many years, astronomers debated whether RCW 114 was physically associated with the nearby WR 90. Modern observations, however, indicate that the nebula is most likely an old supernova remnant located much closer to Earth than WR 90, and that the apparent alignment is simply a chance projection along our line of sight. This makes RCW 114 an excellent example of the importance of combining imaging with spectroscopic and distance measurements to understand the true nature of celestial objects.

Deep images also reveal numerous dark dust clouds crossing the field, together with the dense stellar background of the Milky Way. The enormous angular size of RCW 114 makes it particularly well suited to imaging with a short focal length, allowing the complete remnant and its surrounding environment to be captured in a single frame.

From a scientific perspective, RCW 114 illustrates the late stages of a supernova remnant’s evolution. As the expanding shell disperses into the interstellar medium, it enriches its surroundings with heavy elements synthesized by the progenitor star and by the supernova explosion itself. These elements eventually become incorporated into future generations of stars and planetary systems, making supernova remnants an essential part of the cosmic cycle of matter.

The HRGB image obtained in 2015 beautifully captures the faint, filamentary appearance of this ancient stellar explosion. Using a 105 mm telephoto lens allowed the entire remnant to be framed against the spectacular backdrop of the southern Milky Way, while the pristine skies of Namibia revealed subtle details that would be almost impossible to detect from light-polluted locations. The result is a striking wide-field portrait of one of the largest and oldest visible supernova remnants in the southern sky.

The data calibration, registration and final processing was done with PixIsight. The result is shown below: