1 Main Grb Jet Illustration 16.jpg
Webb telescope

Did the explorers discover other unique features in the most luminous cosmic explosion?

Surendra UikeyPosted by

 

Did the explorers discover other unique features in the most luminous cosmic explosion?

NASA’s NuSTAR X-ray telescope has given astronomers a clue as to why GRB 221009A, the brightest and most energetic gamma-ray burst ever detected, is so powerful. On October 9, 2022, scientists observed this unprecedented event and recorded it as 70 times brighter and more energetic than any other gamma-ray burst they had seen before. NuSTAR has revealed that this enormous burst of energy took place when the core of a massive star, much larger than our own sun, collapsed into a black hole. This event released as much energy in a few minutes as our sun would release in its entire lifetime. While scientists are still on the search for a full explanation as to why GRB 221009A produced such an extraordinary display, they are thankful to have obtained this insight from NuSTAR.


In a study recently published in the journal Science Advances, scientists used NuSTAR observations to analyze the event of a collapsing star that ejected a jet of material that was unlike any other gamma-ray burst jets. This unique jet had certain characteristics that could possibly be sourced from the progenitor star, like its physical properties. Moreover, it is also suggested that an entirely different mechanism could be responsible for launching the brightest jets into space.


This event was truly remarkable – it was far brighter and more energetic than any gamma-ray burst ever seen before. Brendan O’Connor, the lead author of the study and an astronomer at George Washington University in Washington, noted that even more interesting was the unique jet structure which was revealed when analyzing the NuSTAR data. This was particularly exciting since there was no way to study the star that produced this event as it has vanished, but now they have some data giving them clues about how it exploded.


Gamma rays are the most energetic form of light in the universe yet invisible to the human eye, emitting radiation from galaxies billions of light-years away. Gamma-ray bursts are among the brightest cosmic events yet, with some lasting for less than two seconds, while others can radiate for up to a minute or more. Not only do they emit gamma-rays, but they can also emit other wavelengths for weeks. All known gamma-ray bursts have originated from galaxies outside our Milky Way and are bright enough to be spotted from far away, making them an important part of astronomical study.


The Hubble Space Telescope captured the infrared aftermath of a known gamma-ray burst.


Did the explorers discover other unique features in the most luminous cosmic explosion?



The Hubble Space Telescope captured the infrared afterglow of the gamma-ray burst known as GRB 221009A and its host galaxy in a composite image taken on November 8 and December 4, 2022, approximately one and two months after the eruption. The afterglow was visible in the image, with the bright circle indicating its location. This afterglow can still be detected from Hubble for several years to come. This data is important as it allows scientists to better understand the origins and behavior of gamma-ray bursts.




GRB 221009A was a long gamma-ray burst that was so bright that most gamma-ray instruments in space were blinded. However, U.S. scientists were able to reconstruct the event using data from NASA’s Fermi Gamma-ray Space Telescope in order to determine its actual brightness. Additionally, this burst was detected by NASA’s Hubble and James Webb space telescopes, the agency’s Wind and Voyager 1 spacecraft, as well as the ESA’s Solar Orbiter, providing further evidence of its brightness and allowing scientists to better understand this rare phenomenon.



GRB 221009A is a unique gamma-ray burst that has a jet that is much more expansive and bright than other observed gamma-ray bursts. This jet, like most, is shot from the collapsing star with glowing gamma rays radiating from the core. However, GRB 221009A’s jet is more expansive than most, emitting a large amount of stray light and material outside of its beam. This was an unusual observation due to the fact that gamma-ray bursts are normally so compact that their  gamma rays can only be seen when they are pointing almost directly at Earth.



GRB 221009A was observed to have a unique jet structure, with a narrow core and wider, sloping sides. This has never been observed in a long gamma-ray burst jet before. Eleonora Troja of the University of Rome believes that this unique structure is due to some property of the star that was varying as the jet was trying to force its way out. This could have included the size, mass, density or magnetic field of the star. This implies that the energy of the material in GRB 221009A was also varied, meaning that instead of all the material having the same energy, like a single bullet shot from a gun, the energy of the material changed with distance from the jet’s core.



Astronomers have the capability to observe the light from gamma-ray jets, however they cannot resolve images of the jets directly due to the long distance. Thus, researchers have to interpret the light from these events in order to gain understanding of the physical characteristics of faraway objects. To illustrate, it is akin to looking at footprints in the snow and inferring something about the physical traits of the person who left them. In many cases, the light from a cosmic event may have more than one possible explanation. For example, regarding GRB 221009A, X-ray telescopes such as NASA’s Neil Gehrels Swift Observatory and Neutron star Interior Composition Explorer (NICER) as well as ESA’s XMM-Newton telescope were utilized to observe the jet. The data collected by these telescopes helped refine the possibilities, showing that the jet was colliding with interstellar medium which caused X-rays to be emitted.

Leave a ReplyCancel reply