An international research team of the Institute of Astrophysics of the Canary Islands (IAC) and the University of Stockholm has discovered approximately a hundred sources of very red lights, that appear and disappear over a period of time, according to an article published in the magazine 'Astronomical Journal'.
For the study, a sample of 600 million objects recorded in images of the sky dating from the 1950s, comparing them with their counterparts in a modern catalog. The result is the identification of up to 150,000 objects without equivalence between both catalogs.
In the preliminary study of these light sources, a small group of 100 red objects, especially interesting, whose follow-up particularly excites the authors, according to Beatriz Villarroel, from the University of Stockholm and researcher at the IAC, who leads the project and the article. These results can help in the search for sparkling M-type dwarf stars, supernovae with high redshift or other categories of transient red objects not previously cataloged.
"Finding a star that really fades, or a star that appears out of nowhere, would be a precious discovery and certainly would include a new astrophysics beyond what we know today", explains Villarroel. When a star dies, it undergoes very slow changes that turn it into a white dwarf or generate a sudden and bright explosion, that is, a supernova. However, a star that fades can be an example of a new astrophysical phenomenon
The study authors point to a possible explanation based on extremely rare events called "failed supernovae". The theory predicts that a failed supernova occurs when a very massive star collapses in a black hole without any visible explosion.
In the project, called 'Fsources that disappear and appear during a century of observations'(VASCO) is looking for physical indicators that can explain the nature of these phenomena within the Milky Way. Observations such as those found pose a challenge to Astrophysics and allow the consideration of more exotic and speculative explanations such as those included in studies searching for evidence of other technologically advanced civilizations.
"But we are clear that none of these events has shown direct signs of being an extraterrestrial intelligence (ETI). We believe that they are natural astrophysical sources, although somewhat extreme ", warns Martín López Corredoira, IAC researcher and co-author of the article.
As a byproduct, VASCO has the potential to discover extremely variable rare objects. "These objects they can shed light on fast phases, difficult to observe, of stellar evolution and active galactic nuclei, "says Sébastien Comerón, from the University of Oulu (Finland) and also co-authored the article.
Researchers are now looking for the possibility of organizing a citizen science project, so that, aided by artificial intelligence, each of the 150,000 anomalies identified can be visually examined. "We are looking for ways to carry it out as soon as possible. In any case, it is something that we can also address at a later date," said another author, Lars Mattsson, from the University of Stockholm.