How NS-Capture explains “Extreme Supernovae”

In the December 2020 issue of Scientific American (sciam), there is a cover story on “Extreme Supernovae” with subtitle:

“Bizarre stellar explosions challenge our understanding of how stars live and die”

The article, itself, is entitled: “Strange Supernovae Upend Expectations” by author: Anna Y.Q.Ho

This post describes how the Neutron Star Capture Theory (NS-Capture) explains some of the unusual observations of these supernovae.

In particular, the sciam article describes 2 phenomena of the supernova event referred to as AT2018cow:

1. The explosion appeared to be driven by a central engine such as a neutron star (or black hole).
2. When the explosion occurred there already was a “cocoon” of material enveloping the star about 1/1000 of a solar mass.

As explained by NS-Capture, all supernovae should be caused by a captured neutron star (NS) disrupting its companion while spiraling in toward the companion’s core over a period of 100,000 to 1,000,000 years.

Therefore, using NS-Capture, there will always be a NS at the center of the explosion, which has been spun up to a pulsar by accretion during the spiral-in phase, and this central NS pulsar will drive the remnants away, as observed in the Crab Nebula.

There is interesting evidence as to what caused the existence of the “cocoon” prior to the explosion described on this site using Hercules X-1 as an example. More detail can be found on the Hercules X-1 wiki page. Her X-1 has a pulse rate of 1.24 sec, an orbital period of 1.7 days, and a longer term 35 day period that shows the whole system regularly disappearing in x-rays for about 23 days then reappearing for 12 days,

The NS-Capture theory suggests that this 35 day period is caused by the companion star (not the pulsar) expanding and contracting with a 35 day period. When the star has expanded, it envelops the pulsar which is why the pulsar is no longer visible in x-rays. When it contracts, it reveals the pulsar again, which is in a close binary circular orbit around the conpanion star.

Therefore, it is not hard to suggest that some times during the expansion phase, that a whole spherical surface of the companion can be left behind forming a cocoon around the both the star and the pulsar Her X-1.