Composite image from the 2.5-meter Nordic Optical Telescope in La Palma showing SN2014J in the dusty cigar galaxy M82 (credits: J. Johansson). The right upper panel shows a detailed near-infrared image from the 10-meter Keck telecope in Hawaii used to accurately locate the site of the explosion. The bottom right panel indicates the position of the supernova on pre-explosion images from the Hubble Space Telescope.
Composite image from the 2.5-meter Nordic Optical Telescope in La Palma showing SN2014J in the dusty cigar galaxy M82 (credits: J. Johansson). The right upper panel shows a detailed near-infrared image from the 10-meter Keck telecope in Hawaii used to accurately locate the site of the explosion. The bottom right panel indicates the position of the supernova on pre-explosion images from the Hubble Space Telescope.


The lack of pre-explosion detections suggests that the supernova may have originated in the merging of compact faint objects, e.g., two white dwarf stars.

“Until very recently, the leading model for standard candle supernovae was thought to include a companion star from which material was stripped by the white dwarf until the accumulated mass could no longer be sustained by the outwards pressure, leading to a runaway thermonuclear explosion. The observations of SN2014J challenge this theoretical picture”, says professor Ariel Goobar at The Oskar Klein Centre, Stockholm University. 

Type Ia supernovae, like SN2014J, are among the best tools to measure cosmological distances. Thanks to their consistent peak brightness, these ”standard candles” are used to map the expansion history of the Universe.

“Since Type Ia supernovae are very rare there have been very few opportunities to study these explosions in great detail. SN2014J in the nearby galaxy M82 is the closest ‘standard candle’ supernova to explode in at least 42 years, and is therefore very welcome”, says Rahman Amanullah, researcher at The Oskar Klein Centre.

The lessons learned by the studies of SN2014J may be very useful for the analysis of the large Type Ia SN sample that scientists have collected over decades, especially the astrophysical corrections needed to make accurate distance estimates. Only then may we be able to tell what is causing the accelerated expansion of the cosmos.

“Many supernovae explode in clean environments, free of dust in the line of sight. This is not the case for SN2014J, which gives us a unique opportunity to study both the properties of the supernova explosion and of the intervening dust”, says PhD student Joel Johansson at The Oskar Klein Centre.

A better understanding of the physics behind Type Ia supernovae and the material surrounding the explosion and dimming some of the light is crucial to further refine the measurements of the expansion history of the Universe.

The iPTF project is a scientific collaboration between Caltech; Los Alamos National Laboratory; the University of Wisconsin, Milwaukee; the Oskar Klein Centre in Sweden; the Weizmann Institute of Science in Israel; the TANGO Program of the University System of Taiwan; and the Kavli Institute for the Physics and Mathematics of the Universe in Japan.