The explosion of supernova SN 2018ivc has emerged as part of a distinct and evolving class of stellar explosions. This assessment is supported by updates from the National Astronomical Observatory of Japan (NAOJ) and conveyed through scholarly reporting from the Japanese agency’s communications channel. (Source: NAOJ)
During a supernova, brightness can surge dramatically, occasionally surpassing the combined light of an entire galaxy. This dramatic rise is tied to the final stages of massive stars that have exhausted their hydrogen fuel, along with dynamic interactions between stellar material and, in some cases, a white dwarf companion. SN 2018ivc, identified in 2018 within the Cetus constellation, is situated roughly 3.2 million light-years from Earth. (Source: NAOJ)
In recent analyses, researchers led by Keiichi Mayeda and colleagues have concluded that SN 2018ivc does not fit neatly into previously cataloged patterns. Initially categorized as a type II supernova (IIL) arising from the core collapse of a massive star, the event challenged this classification as more data accumulated. Months of follow-up observations were carried out with the assistance of the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, which specializes in the microwave portion of the spectrum. (Source: NAOJ)
What stood out most to the team was the unusual evolution of brightness in the microwave band. In the first year, the microwave light gradually dimmed, only to rise sharply later. This is unconventional for IIL supernovae, which typically show a different trajectory. Detailed studies of SN 2018ivc’s remnants revealed that the explosion involved a binary system where two stars orbited each other with a period of roughly 4.9 to 5.3 years. One star appears to have nearly exhausted its hydrogen supply, shedding much of its outer envelope about 1,500 years before the explosion, after which its companion began accreting the remaining material. The observed flash-era behavior does not align with established models, prompting a reconsideration of the mechanisms driving this event. (Source: NAOJ)
Ultimately, the interaction between the dying star and its companion led to the demise of the first star, unleashing a powerful flash and a shock wave that traversed the star’s previously ejected material, causing it to glow in the aftermath. This chain of events challenges existing classifications and highlights the need for nuanced interpretation of pre-explosion mass loss and binary dynamics in shaping supernovae. (Source: NAOJ)
In parallel, discoveries in other fields remind researchers that astronomy often requires cross-disciplinary perspectives. For example, advances in ancient DNA analysis have reshaped views in anthropology regarding human refuges during the ice ages, illustrating how breakthroughs in one domain can illuminate questions in another. (Source: NAOJ)