After the supernovae of antimatter, here are the electron-capturing supernovae. The concept is about 40 years old, but a series of powerful observations seem to show that the universe was aware of the speculations of astrophysicists and that the SN 2018zd supernova is indeed an example of this strange phenomenon that probably also describes the famous supernova of 1054.
TheFrom SN 2018zd fell first in the net Las Cumbres Observatory But since the supernova it has had several which did not allow it to fit within the framework of the two main types of supernovae now well known, astrophysicists delved into the astronomical archives of the noospheres that preserved the memory of galactic observations 2146, do it with Hubble. Pictures of this spiral galaxy, located in from , revealed that SN 2018zd’s predecessor was a massive star that is said to be in the super asymptotic branch of giants (Super convergent giant branch or Sagb in English).
Nuclear astrophysics, the key to supernovae
Let us remember that at the beginning of the 1930s, astrophysicists Walter Bade and Fritz Zwicky realized that it was necessary to introduce a new category in astronomy. , these bright transiting stars appear only once in the sky and then disappear forever. The name they propose will bring fortune: . En compagnie de Rudolph Minkowski, And the nephew of the famous mathematician, Hermann Minkowski, Buddy realizes that these supernovae can also be separated into two types, depending on the and characteristics of light curves whose changes vary over several weeks in particular. Other sections will be added but this work is the origin of modern taxonomy with SN II and SN Ia.
Animation movie Valley of stability It shows how nuclear physics works in stars and makes the material we’re made of. We discover that stars live by fusion of cores in their cores, and how the catastrophic end of some of them creates the heaviest cores. © CEA, Animea 2011
Also in the 1930s, Walter Bade and Fritz Zwicky, very soon after Chadwick discovered He uses, with his student Volkov, the results of Richard Tolman regarding the fluid fields in and makes the first real calculations of the concept of neutron stars. As early as 1939, these two researchers presented them as atomic nuclei the size of a star. Together with fellow student Hartland Snyder, Oppenheimer will study what happens to such objects when they collapse gravitationally, laying the foundation for a theory .In 1932, some supernovae are massive explosions. accompany The stars that will become . In 1938,
In the case of SN Ia, things are quite different. It all starts with a star less than 8 solar masses that evolves with a loss of mass and ends up having an inert core containing nuclei (about 1.4 solar masses), the star does not collapse under its influence Because there is a decompose of relativ electrons as we say in language . A white dwarf will explode with a thermonuclear explosion if received from a companion star of ل Across So much so that its mass exceeds that of Chandrasekhar.Based on Basically. Thermonuclear reactions also stopped at this point and as long as the mass stopped Not beyond famous
Relative electron gas absorbed by the nuclei
An attentive reader will note that until now there has been no doubt about the fate of stars with masses between 8 and 10 solar masses. To specifically explain the fate that awaits them, the theory of electronic supernovae was formulated in the early 1980s by , then by other nuclear astrophysicists.
For these stars, they also evolve into a white dwarf but their core begins to contain بالAnd you instead of carbon. There comes a time when these cores capture decaying electron gas even though the star was not massive enough to produce the thermonuclear reactions leading to iron cores.
When the electron gas disappears, theAlso, which leads to the release of energy and the collapse of gravity giving a new type of supernova, the electron supernova, but also with a core of neutrons left over from the explosion.
The fact that the generator star of SN 2018zd was indeed Sagb, and therefore with sufficient mass, that chemical composition anomalies were detected and that the supernova did not produce many radioactive elements, argues for other properties that make SN 2018zd a very strong candidate for the electronic supernova title.
If this is the case, this gives us more confidence in a hypothesis that has been proposed in the case of a mythical supernova, that of 1054 and which we still observe to the rest of the day in addition to the resulting neutron star which is also a neutron star. It was relatively bright compared to SN II models that produce a neutron star. They concluded that his It may have been artificially enhanced by supernova collisions with matter rejected by the original star, as shown in the case of SN 2018zd, and as predicted by electronic supernova models predicting significant mass losses before the star exploded.. In fact, some astrophysicists let it be known that, according to the data of that time, a supernova