GRBs tagged posts

After its “birth” in the Big Bang, the universe consisted mainly of hydrogen and a few helium atoms. These are the lightest elements in the periodic table. More-or-less all elements heavier than helium were produced in the 13.8 billion years between the Big Bang and the present day.

Stars have produced many of these heavier elements through the process of nuclear fusion. However, this only makes elements as heavy as iron. The creation of any heavier elements would consume energy instead of releasing it.

In order to explain the presence of these heavier elements today, it’s necessary to find phenomena that can produce them. One type of event that fits the bill is a gamma-ray burst (GRB)—the most powerful class of explosion in the universe...

First model that is fully consistent with all FBOT observations. Ever since they were discovered in 2018, fast blue optical transients (FBOTs) have utterly surprised and completely confounded both observational and theoretical astrophysicists.

So hot that they glow blue, these mysterious objects are the brightest known optical phenomenon in the universe. But with only a few discovered so far, FBOTs’ origins have remained elusive.

Now a Northwestern University astrophysics team presents a bold new explanation for the origin of these curious anomalies. Using a new model, the astrophysicists believe FBOTs could result from the actively cooling cocoons that surround jets launched by dying stars...