Resurrected supernova provides missing-link

Date:
March 2, 2023
Source:
National Institutes of Natural Sciences
Summary:
Astronomers have discovered a supernova exhibiting unprecedented
rebrightening at millimeter wavelengths, providing an intermediate
case between two types of supernovae: those of solitary stars and
those in close-binary systems.


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FULL STORY ========================================================================== Astronomers have discovered a supernova exhibiting unprecedented
rebrightening at millimeter wavelengths, providing an intermediate case
between two types of supernovae: those of solitary stars and those in close-binary systems.


==========================================================================
Many massive stars end their lives in a catastrophic explosion known as
a supernova (SN). Supernovae increase rapidly in brightness, and then
fade over the course of several months.

Astronomers have long known that the presence or absence of a close
binary companion can affect the evolution of massive stars. In a close
binary system, gravitational interactions with the binary companion
will strip large amounts of material from the SN progenitor long before
the final explosion. In these cases, the progenitor will be quiet up
until the time of the actual SN. On the other hand, in the case of an
SN progenitor with no binary companion or a distant companion, leading
up to the SN explosion the progenitor will keep most of its initial mass.

Of course smart alecs will ask, "What happens when the binary is not
too close and not too distant?" Not just smart alecs, astronomers also
wanted to know.

The break came when an international research team, led by Keiichi
Maeda (Professor at the Graduate School of Science, Kyoto University)
and Tomonari Michiyama (ALMA Joint Postdoctoral Fellow at the Graduate
School of Science, Osaka University), used ALMA (The Atacama Large Millimeter/submillimeter Array) to monitor a supernova known as SN 2018ivc
as it dimmed for about 200 days after the initial explosion. The results
showed that SN 2018ivc was an unusual object, so the team decided to check
up on it again, at about 1000 days after the explosion. They found that
the object was actually rebrightening, the first time this phenomenon
had ever been observed in millimeter wavelength radiation.

Comparison to numerical modeling suggests that interaction with an intermediate-distance binary companion about 1500 years before the SN
explosion created a large hollow shell of circumstellar medium. At 200
days after the SN, the ejecta flying out from the explosion had yet to
reach the shell. Then sometime between 200 and 1000 days, the ejecta
collided with the circumstellar medium.

* RELATED_TOPICS
o Space_&_Time
# Stars # Astrophysics # Nebulae # Space_Telescopes #
Astronomy # Asteroids,_Comets_and_Meteors
* RELATED_TERMS
o Supernova o Gravitational_wave o Extrasolar_planet
o Interstellar_medium o Nuclear_fusion o
Neptune's_natural_satellites o Open_cluster o
Uranus'_natural_satellites

========================================================================== Story Source: Materials provided by
National_Institutes_of_Natural_Sciences. Note: Content may be edited
for style and length.


========================================================================== Journal Reference:
1. Keiichi Maeda, Tomonari Michiyama, Poonam Chandra, Stuart Ryder,
Hanindyo
Kuncarayakti, Daichi Hiramatsu, Masatoshi Imanishi. Resurrection
of Type IIL Supernova 2018ivc: Implications for a Binary
Evolution Sequence Connecting Hydrogen-rich and Hydrogen-poor
Progenitors. The Astrophysical Journal Letters, 2023; 945 (1):
L3 DOI: 10.3847/2041-8213/acb25e ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2023/03/230302093414.htm

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