> ## Content Index
> Fetch the complete content index at: https://balaustine.mymagic.page/llms.txt
> Use this file to discover other available public pages before exploring further.

# Tracing the origins of Pu-244
- URL: https://balaustine.mymagic.page/tracing-the-origins-of-pu-244/
- Published: 2015-12-10T18:05:07.000Z
- Updated: 2015-12-10T18:05:07.000Z
- Description: Plutonium-244 could've come from neutron-star mergers, so knowing its abundance could reveal the rate at which such mergers happen.
- Author: VM
- Tags: Uncategorized, actinides, gravitational waves, neutron star mergers, nucleosynthesis, plutonium, Pu-244, r-process, #Migrated-1787483357778, #wp, #wp-post, #Import 2026-08-23 11:09

Excerpt:

> The heaviest naturally occurring elements are thought to form not when a star is alive but when it begins to die. Specifically, in the explosion that results when a star weighing 8x to 20x our Sun dies, in a core-collapse supernova (cc-SNe). In this process, the star first implodes to some extent before being rebounded outward in a violent throwing-off of its outer layers. The atoms of lighter elements in these layers could capture free neutrons and transmutate into an atom of a heavier one, called the r-process.  
>  
> The rebound occurs because if the star's core weighs less than about 5x our Sun (*our entire Sun!*), it doesn't collapse into a blackhole but an intermediary state called a neutron star – a small and [extremely dense](http://thecentrifuge.net/2014/05/05/the-secrets-of-how-planets-form/?ref=balaustine.mymagic.page) ball composed almost entirely of neutrons.  
>  
> Anyway, the expelled elements are dispersed through the interstellar medium, the region of space between stars. Therefrom, for example, they could become part of the ingredients of a new nebula or star, get picked up by passing comets or meteors, or eventually settle down on the surface of a distant planet. For example, the isotope of one such element – plutonium (Pu) – is found scattered among the sediments on the floor of Earth's deepest seas: plutonium-244.  
>  
> Based on multiple measurements of the amount of Pu-244 on the seafloor and in the interstellar medium, scientists know how the two amounts correlate over time. And based on astronomical observations, they also know how much Pu-244 each cc-SNe may have produced. But what has caught off recent scientists is that the amount of Pu-244 on Earth over time doesn't match up with the rate at which cc-SNe occur in the Milky Way galaxy. That is, the amount of Pu-244 on Earth is 100 times lower than there would've been if all of it had to have come from cc-SNe.  
>  
> So where is the remaining Pu-244?  
>  
> Or, a team of astrophysicists from the Hebrew University, Jerusalem, realised, was so much Pu-244 not being produced in the first place?

Read the full piece [here](http://thewire.in/2015/12/10/alternate-source-of-plutonium-isotope-sets-cap-on-gravitational-wave-detection-17069/?ref=balaustine.mymagic.page).