Carnegie Institution for Science | 2019 May 07
Detection of a supernova with an unusual chemical signature by a team of astronomers led by Carnegie’s Juna Kollmeier—and including Carnegie’s Nidia Morrell, Anthony Piro, Mark Phillips, and Josh Simon—may hold the key to solving the longstanding mystery that is the source of these violent explosions. Observations taken by the Magellan telescopes at Carnegie’s Las Campanas Observatory in Chile were crucial to detecting the emission of hydrogen that makes this supernova, called ASASSN-18tb, so distinctive. ...
- Cartoon courtesy of Anthony Piro illustrates three possibilities for the origin of the mysterious hydrogen emission from the Type IA supernova called ASASSN-18tb that was observed by Carnegie astronomers. Starting from the top and going clockwise: The collision of the explosion with a hydrogen-rich companion star, the explosion triggered by two colliding white dwarf stars subsequently colliding with a third hydrogen-rich star, or the explosion interacting with circumstellar hydrogen.
Type Ia supernovae originate from the thermonuclear explosion of a white dwarf that is part of a binary system. But what exactly triggers the explosion of the white dwarf—the dead core left after a Sun-like star exhausts its nuclear fuel—is a great puzzle. A prevailing idea is that, the white dwarf gains matter from its companion star, a process that may eventually trigger the explosion, but whether this is the correct theory has been hotly debated for decades.
This led the research team behind this paper to begin a major survey of Type Ia supernovae—called 100IAS ...
In recent years, astronomers have discovered a small number of rare Type Ia supernovae that are cloaked in large amount of hydrogen—maybe as much as the mass of our Sun. But in several respects, ASASSN-18tb is different from these previous events. ...
Hα Emission in the Nebular Spectrum of the Type Ia Supernova ASASSN-18tb ~ Juna A. Kollmeier et al
- Monthly Notices of the RAS 486(3):3041 (July 2019) DOI: 10.1093/mnras/stz953
- arXiv.org > astro-ph > arXiv:1902.02251 > 06 Feb 2019