The Hubble Space Telescope sent back an image of the powerful intergalactic explosion that surprised astronomers. The main hypotheses associate such events with the destruction of stars by black holes or the fusion of neutron stars. This event raised new questions about astronomical events and highlighted the versatile nature of unexplored space.

Recently, the Hubble telescope witnessed an unusual cosmic explosion that created a bright flash of light between two galaxies located 3 billion light years from Earth. One of the brightest bursts of blue light in the universe, this optical burst lasted only a few days and became a new example of a rare cosmic phenomenon called light-fast blue optical transients (LFBOTs).

LFBOTs are a complete mystery and are characterized by rapid development, absence of absorption or emission lines in the blue range of the spectrum in the early stages, and bright emission in the region of X-rays and radio waves. The position of each line in the light spectrum depends on the energy of the transition, and the width and height of the line can provide information about the temperature, density, and other properties of the emitting or absorbing material. High optical brightness and fast fading make LFBOTs a rare and enigmatic class of astrophysical phenomena.

The first known LFBOT was discovered in 2018 and was called “Cow” (AT2018cow). It was located 200 million light-years away in the spiral arm of the galaxy, was 100 times brighter than a normal supernova, and was active in the radio, ultraviolet, and X-ray bands. If it were a supernova, its behavior would be very unusual because supernovae usually remain bright for several weeks or even months and have a well-visible spectrum. But “Cow” faded after a few days.

On June 16, 2018, an unusual cosmic explosion called “The Cow” occurred in the constellation Hercules, about 200 million light-years from Earth. Scientists are still unsure of the reasons for this phenomenon (image source: Raffaella Margutti / NASA, Northwestern University)

A new LFBOT called The Goldfinch (AT2023fhn), discovered April 10 by the ZTF Observatory in Palomar, California, has become a new mystery for astronomers. According to the Gemini South telescope in Chile, the Goldfinch’s temperature was 20,000 degrees Celsius; this was much cooler than some massive stars and much cooler than supernovae.

Goldfinch is unique in its location in intergalactic space, approximately 50,000 light-years away from a large spiral galaxy and 15,000 light-years away from a small galaxy, unlike previous LFBOTs located directly in the spiral arms of galaxies. This radically changes astrophysicists’ opinion about the possible nature of such a rare phenomenon.

Ashley Chrimes, a research scientist at the European Space Agency (ESA) and lead author of a new paper on the newly discovered LFBOT, notes: “The more we learn about LFBOTs, the more they surprise us. We show that LFBOTs can originate at a significant distance from the center of the nearest galaxy and that the location of the Goldfinch is not what we would expect from any type of supernova. “.

Crimes and his team focused on two possible versions of the event. The first is that The Goldfinch is a flash of light resulting from the disintegration of a star by an intermediate-mass black hole 100 to several thousand times the mass of the Sun. Intermediate-mass black holes are believed to be found in the cores of some globular star clusters lurking on the outskirts of galaxies.

According to another version, The Goldfinch may be a kilonova, the result of a collision between two neutron stars (or sometimes a neutron star and a black hole). Crimes plans to use the powerful optics of the James Webb Space Telescope (JWST) to search for similar clusters containing the Goldfinch in the future.

This discovery raises more questions than it answers and requires further research to clarify the nature of this mysterious cosmic phenomenon. Each new discovery in this field expands the boundaries of understanding the universe by pushing us to rethink already known facts and theories. Source