Eta Carinae is brightening as never before. The event is coming!

lest apply the reality check of the " inverse square rule " to any aledged effect that this will have on earth

originally posted by: ignorant_ape
lest apply the reality check of the " inverse square rule " to any aledged effect that this will have on earth

that is what protects us from regular nova and super nova but hyper novas are millions of times more energetic. ordinarily something 8000 light years away is no concern. not so with these. the only thing saving us from these is they are very very rare and on top of that they only emit mostly in the direction of thier axis of rotation. but even 8000 light years away these are capable or reaching out and touching someone.

originally posted by: stormbringer1701
Temporarily is a relative term. it is posulated that one of these hypernovaes caused the greatest extinction eveny of the silurian era.

gamma ray emissions of a wolf rayet hypernova last three months. during that time earth rotates on its axis at least 90 times and it, the moon and any other screening planets move 1/4 of a years worth of their orbits.

once the ozone layer is compromised 90 percent of the biodiversity of that era died and that is with the shielding effect of the ocean as the life of that period was almost entirely under the seas.

Yes, but it's the difference between the Earth becoming sterile and humanity dying off, and a catastrophic event we can overcome.

In 2011, light echoes from the 19th century Great Eruption of Eta Carinae were detected using the U.S. National Optical Astronomy Observatory's Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory. Analysis of the reflected spectra indicated the light was emitted when Eta Carinae was a 5000 K G2-to-G5 supergiant, some 2000 K cooler than other supernova impostor events. - en.wikipedia.org...

Perhaps the current brightening will also be a supernova impostor event, and won't have any effect apart from making the star very bright, perhaps as bright as Sirius.

Eta Carinae is not a Wolf-Rayet star (yet).

I think the biggest threat from when it goes hypernova will be to satellites, spacecraft, and any astronauts in space.

originally posted by: ignorant_ape
lest apply the reality check of the " inverse square rule " to any aledged effect that this will have on earth

The inverse square rule doesn't apply to focused emissions, such as laser beams or those gamma rays from supernovae or neutron stars. That's why the orientation of those rays relative to Earth is important.

~~~

P.S. let's give special love to the Homunculus Nebula surrounding the star. It is bright enough that when you look at it through a large telescope, you can see its golden colouration.



Here's an observer's description, using a 12-inch Dobsonian telescope:

Very distinct yellow/gold on star itself and the lobes were both clearly yellow as well but not as bright as the central star. There are clearly two lobes with the very bright central star between the lobes. Trailing is the very bright lobe. Leading lobe is on West lobe that is dimmer. My first impression is as if a notch is taken out on this lobe more towards north in this lobe. There is a distinct jet that that shoots North that requires moments of great seeing to clearly see. The jet starts just a bit east of Eta Car star and extends a length of around half the diameter of either lobe. On NW lobe there is a distinct darker area within the lobe. ON South lobe there is more of a notch. There is mottled appearance to the trailing brighter lobe in moments of great seeing. Also on that Easterly side there are two dark areas as we move from EtaCar out along the major axis to the trailing edge of the more easterly lobe which I felt was like a peanut shape as this structure necks down in the middle. Must wait for best seeing to really see these. The jet also comes and goes with seeing. The jet points just slightly West of two field stars on northern side of the clearing around Eta Car homunculus nebula main lobed structure. These two stars of very similar magnitude look real nice taken all together for a tight field along with the homunculus nebula.

old.observers.org...

What is remarkable is that this nebula is very recent, originating in the 19th century outburst.

en.wikipedia.org...

some scientists think the silurian ordovician extinction event was caused by a hypernova about 6000 light years from earth. this is a minority opinion but one considered plausible. that is it is not rejected on the scientific merits.

the big thing is not whether it happened that way. it's that scientists believe that a hypernova at several thousand light years distant would have had the following effects:

Gamma ray burst hypothesis[edit]
A small minority of scientists have suggested that the initial extinctions could have been caused by a gamma ray burst originating from a hypernova within 6,000 light years of Earth (in a nearby arm of the Milky Way Galaxy). A ten-second burst would have stripped the Earth's atmosphere of half of its ozone almost immediately, exposing surface-dwelling organisms, including those responsible for planetary photosynthesis, to high levels of ultraviolet radiation.[13][14][15][16] Although the hypothesis is consistent with patterns at the onset of extinction, there is no unambiguous evidence that such a nearby gamma ray burst ever happened.

note that that was for a ten second burst. 50 percent reduction in ozone. ten seconds. not a full 90 day bath in lethal gamma rays.

originally posted by: stormbringer1701
it is pointing in our general direction.

How can a star point in any direction?

originally posted by: hellobruce

originally posted by: stormbringer1701
it is pointing in our general direction.

How can a star point in any direction?

have you seen a picture of eta carinae?

to answer your question the gamma ray or x ray jet of several types of stellar objects are aligned with the poles or axis of spin. so a star is pointed at us when one of ti's poles is facing our direction. in the case of many stars including eta carinae the axis of spin is obvious and in the case of eta carinae it is definitely pointed in our direction we are looking at one of the poles when we see that star. i'll try to find a picture for you.

look at the picture here:

www.space.com...

it's kind of obvious we are looking "down" on the pole.

originally posted by: hellobruce

originally posted by: stormbringer1701
it is pointing in our general direction.

How can a star point in any direction?

a reply to: wildespace

actually - it [ invers square ] does apply to focused emmitters

this can be demonstrated by using data from the appollo laser ranging expeiments .

originally posted by: ignorant_ape
a reply to: wildespace

actually - it [ invers square ] does apply to focused emmitters

this can be demonstrated by using data from the appollo laser ranging expeiments .

Energy falling off "as 1/r2" is true for light expanding from the source in a sphere - the energy is spread across the entire surface of the sphere which area is increasing as r2. The inverse square law assumes the source is radiating isotropically. Lasers do however have a far-field divergence angle which can be used to calculate the irradiance profile some distance away. This far-field divergence angle depends on the wavelength of the laser and the minimum spot size of the beam. www.physicsforums.com...

originally posted by: glend

Brightness from year 1810 to now Source: etacar.fcaglp.unlp.edu.ar...

Sorry, what are we meant to be worrying about? That chart shows that it is still five orders of magnitude less bright than it was in the 1840s, ie 100 times dimmer.

(One order of magnitude is about 2.512 times change in brightness. 2.512^5 = 100)

Also the increase in brightness is much less steep than it has been in the past so "brightening as never before" seems to be total nonsense.

ugh.. i wrapped my skull around some of this

this all sounds like the blue-star kachina thing (the hopi prophecy?)
and the resultant wave sounds a lot like the "5th dimensional transition" all those 2012 squirrel-huggers were droning on about.. how it was going to hit the earth & wipe us all out send all the good souls to the happy place while all the bad souls were stuck on the earth (ever seen that final fantasy movie?)

"master blaster runs barter town" -loved the mad max pic back there

..enough time to finish watching game of thrones ya reckon?

well the thing is we don't know when eta carinae will blow. it is considered immanent in cosmological terms bu that could be anywhere in the next 100K years. but because of the distance it could have happened 7999 years ago and we would not know it happened until the light form the event gets here (possibly tomorrow) but if it does happen scientists are unsure that it will manifest the gamma ray burst because it only sometimes happens. and the pointing precision of the pole is currently estimated to be around 35 percent rather than the deadly 16 percent or so that was initially believed. so if it does go off it probably will miss us entirely or be a glancing hit.

but the threat is real. it could be doom. there is not much we could realistically do about it. the solutions involve vast underground shelters with underground farms or space born shields that can antennuate gamma radiation that are larger in diameter than the earth. shielding hard gammas is very hard. we are just now developing meta-materials that can optically bend gamma rays. but to make such a shield in space is beyond our capabilities.

and it's like smoking the damage is unseen until it is too late so smokers often don't take action until they are already cancer victims. politically you could not convince the people of the earth to work towards the extremely expensive goal of a shield or even shelters for some event they can hardly believe is real.

Did I miss someting? From what I read it will happen within the next 1 Million Years....
SO, I feel safe, kinda. I would hope we have advanced greatly by then.....

Heh, we can make bets on which will go off first, Eta Carinae or Betelgeuse. Beetle Juice is also expected to blow "any time soon".

originally posted by: Rob48

originally posted by: glend

Brightness from year 1810 to now Source: etacar.fcaglp.unlp.edu.ar...

Sorry, what are we meant to be worrying about? That chart shows that it is still five orders of magnitude less bright than it was in the 1840s, ie 100 times dimmer.

(One order of magnitude is about 2.512 times change in brightness. 2.512^5 = 100)

Also the increase in brightness is much less steep than it has been in the past so "brightening as never before" seems to be total nonsense.

"Brightening as never before during our campaign." - it's important to read articles carefully.

No one says we should start worrying. But Eta Carinae may be heading for another outburst, or it might be actually heading for a hypernova. Even if it's only an outburst, resulting in it becoming a very bright star, it's still significant astronomy news.

a reply to: glend

We're all dead. (Putting on a New Years party hat) ...Someone pass me a fifth and a jar of cashews. I'm going out with a bang.

a reply to: wildespace

I'd out my money on Eta Carinae. A 99 study examined the pronounced brightening that occurred in 1998 (iopscience.iop.org...).

The hypothetical result is that the star itself appears dramatically brighter, because its line-of-sight extinction has been substantially reduced, while the Homunculus brightens by a lesser amount because of a combination of modestly larger intrinsic brightness and modestly smaller circumstellar extinction. We have no particular confidence that this is the correct explanation, but it seems plausible and illustrates that the observed behavior is not absurd from a theoretical viewpoint.

The hypotheses of a significant luminosity increase and of rapid grain destruction are each independently of great theoretical interest, and we cannot yet rule out the possibility of a new major eruption. Evidently η Car, always a rewarding subject for observation, merits special attention in the next few months and years.

Star may already be over the Eddington limit but interstellar gas from previous eruption obscures our sight. Certainly be very exciting for astronomers if she does blow again.

Shields up.

By that chart it looks like it could be another 100 years before we see the star at it's 1800s-level brightness.

Ha. Maybe that is why our "end of the world" date fluctuates so much. Because this star is our killer, but it's dying breaths is in a million year span of time. 2012...no wait, 2015! No, no, no it was 1999...etc.