Astronomers uncover new clues to the star that wouldn’t die

About 170 years ago, astronomers witnessed a major outburst by Eta Carinae, one of the brightest known stars in the Milky Way galaxy. The blast unleashed almost as much energy as a standard supernova explosion.

Read more at: https://phys.org/news/2018-08-astronomers-uncover-clues-star-wouldnt.html#jCp

However, astronomers can use nature’s own “time machine,” courtesy of the fact that light travels at a finite speed through space. Rather than heading straight toward Earth, some of the light from the outburst rebounded or “echoed” off of interstellar dust, and is just now arriving at Earth. This effect is called a light echo. The light is behaving like a postcard that got lost in the mail and is only arriving 170 years later.

So the original light bounced off a cloud of gas that was further away behind the system.

Tau.Neutrino said:

However, astronomers can use nature’s own “time machine,” courtesy of the fact that light travels at a finite speed through space. Rather than heading straight toward Earth, some of the light from the outburst rebounded or “echoed” off of interstellar dust, and is just now arriving at Earth. This effect is called a light echo. The light is behaving like a postcard that got lost in the mail and is only arriving 170 years later.

So the original light bounced off a cloud of gas that was further away behind the system.

Or, more correctly, beside the system. You know two famous light echos already: V838 Monocerotis and Hanny’s Voorwerp

> The new measurements of the 1840s eruption reveal material expanding with record-breaking speeds up to 20 times faster than astronomers expected. The observed velocities are more like the fastest material ejected by the blast wave in a supernova explosion, rather than the relatively slow and gentle winds expected from massive stars before they die.

Well duh. That’s why they call it a “supernova imposter”. It was bright enough to be a supernova. No-one would expect “slow and gentle winds”.

> a prolonged stellar brawl among three rowdy sibling stars

I hadn’t thought of that. I’m withholding judgement based on that fact that the main star remaining is extremely peculiar, closer to going supernova than anything within 7,500 light years of Earth. If it was just an innocent bystander in an explosion 170 years ago then that’s no more likely than it exploding twice. Further, if the “innocent bystander” theory is accepted then where is the neutron star or black hole, it’s unlikely to have been swallowed.

But they could be right.