06/29/2021 at 12:16 PM CEST
Supernova SN 1054 is one of the few for which there is written evidence of observations of the explosion. Prized in the Middle Ages, until now it had not been able to be accurately classified or fully characterized. Recent research, carried out by specialists from the University of California at Santa Barbara, has found that it corresponds to a new typology: electron capture supernovae.
SN 1054 was seen in different parts of the earth in 1054 AD. C., from which it takes its name. For Chinese and Arab astronomers of the time, it was visible in daylight for 23 days, while its light lasted in the night sky for 653 nights, starting on July 5 of that year.
There are also records of native North American peoples, such as the Anasazi civilization, which inhabited the southwest of the current territory of the United States. Its members saw and recorded the supernova SN 1054: they left strange symbols and pictures that document the observation. In addition, the astronomical event was represented in a petroglyph used as a kind of map of the celestial vault.
The remnant of the supernova SN 1054 originated the so-called crab nebula, which together with the pulsar it contains make up the most studied astronomical structure beyond the Solar System. This is due to their particular conditions, mainly the accuracy of the explosion date, something unusual when studying supernovae. At the same time, both the nebula and the pulsar rank among the brightest and most accessible objects for observation in their respective categories.
Related topic: They discover a neutron star inside the closest supernova to Earth.
A new typology
Now, the new study by American scientists has determined that that gigantic explosion that bathed the medieval skies in light was a new type of supernova. The new variety discovered, and whose parameters correspond to the medieval example, among other things because of its high luminosity, is called an electron capture supernova.
According to a press release, it is characterized by an anomalous behavior of the electrons in the atomic nuclei, determining that the core of the star bends under its own weight and collapses, generating the supernova. The results of the research have been published in the journal Nature Astronomy.
The discovery was made by studying another supernova and its host galaxy, named SN 2018zd. Using data from the Las Cumbres Observatory and the Hubble Space Telescope, astronomers appreciated that this supernova had many unusual features, some of which were first seen when analyzing such an astronomical event.
By not being able to be classified into either of the two main types of supernovae, known as thermonuclear collapse and iron core, scientists were able to determine that the observed example falls within a new variety, which has been called electron capture supernova and that it has the characteristics indicated previously.
However, the findings related to SN 2018zd led specialists to re-study the case of SN 1054, the supernova seen in the Middle Ages. By comparing the characteristics, they concluded that the cosmic phenomenon appreciated and documented at that time could also be classified as an electron-capturing supernova.
The discovery could shed light on vital aspects such as the formation of some neutron stars, the life and death of massive stars or with respect to the way in which the elements that compose them are dispersed throughout the universe.
The electron-capture origin of supernova 2018zd. Hiramatsu, D., Howell, DA, Van Dyk, SD et al. Nature Astronomy (2021) .DOI: https: //doi.org/10.1038/s41550-021-01384-2
Photo: Composite image of the Crab Nebula, created by combining data from five telescopes that span almost the entire width of the electromagnetic spectrum. Credit: NASA, ESA, NRAO / AUI / NSF and G. Dubner (University of Buenos Aires).