Yep. That’s pretty much my understanding too.

I was really just joking with the BA sorta saying in his book that Eta Carinae could be *the* death(from-the skies!) star and then saying here that it doesn’t pose any threat at all and noting that minor inconsistency.

But maybe our understanding of the GRB risk Eta Car poses has shifted since the book was written, it’s no huge deal after all – just potentially the end of the world!*

Seems various sources differ on exactly how bright – four or five million times – Eta Carinae is too.

Thanks for the link there.

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* Mind you, almost certainly NOT the end of the world just the very remotest, slim possibility of it.

“….if Eta Carinae is too far away to hurt us why did you choose it to be the death star in your ‘Death from the Skies’ book, page 103, chapter 4 (Gamma Ray Bursts) , then? Don’t you think it could produce a lethal GRB after all, eh?”

Although I haven’t read the book…..YET(although it’s on my to do list), I do think the possibility of Eta Carinae producing a GRB ‘jet’ is a very real one. However, due to the rotation axis of Eta Car being inclined ~41 degrees to our line of sight, the intersection of any beamed emission with the Earth seems unlikely. So will Eta Car produce a GRB jet?…maybe. Is the Earth in danger of a GRB jet from Eta Car?…probably not.

Check out the 2007 paper “Superluminous supernovae: no threat from Eta Carinae” and references therein: http://arxiv.org/ftp/arxiv/papers/0705/0705.4274.pdf

And one day Eta Car will explode. It’s too far away to hurt us, but what a sight that’ll be!

So, if Eta Carinae is too far away to hurt us why did you choose it to be the death star in your ‘Death from the Skies’ book, page 103, chapter 4 (Gamma Ray Bursts) , then? Don’t you think it could produce a lethal GRB after all, eh?

And even now, just sitting there not exploding, it still shines about 4 million times brighter than the Sun. Four million. If the Earth were as close to Eta Car as we are to the Sun, we’d be vaporized into an ionized memory.

I thought Eta Carinae boasted five million times the solar luminosity, BA, no?

Okay, I’m sure this merely a ballpark estimate & there are uncertainties and some rounding up / down involved but that’s certainly what I’ve read – so are you shortchanging Eta Car by a million sunpower here?

There are something like 2000 stars in that cluster alone, including one monster that has 80 times the mass of the Sun, near the theoretical limit of how big a star can be without tearing itself apart.

Could be mistaken but don’t I recall reading somewhere of a star that’s wellover a hundred solar masses – a new unlikely stellar “heavyweight” (heavy-mass?) champion at the core of a very large galactic open cluster – R136 A1 or something like that?

Also weren’t the very first stars ever formed up to even 300 or so solar masses – “cheating” of course, by their exceptionally low metallicity but still?

Mind you, as noted already, there are only *very* minor nitpicks in an otherwise spot on and very enjoyable blog post here – I’m certainly not complaining or meaning to give you a hard time here, Phil. Just my inner pedant, really. (&, yes, I’m certainly imperfect and fallible and prone to numerous typos myself.)