APOD: WR 104: A Pinwheel Star System (2014 Jun 03)

[APOD Robot]

WR 104: A Pinwheel Star System

Explanation: Might this giant pinwheel one-day destroy us? Probably not, but investigation of the unusual star system Wolf-Rayet 104 has turned up an unexpected threat. The unusual pinwheel pattern has been found to be created by energetic winds of gas and dust that are expelled and intertwine as two massive stars orbit each other. One system component is a Wolf-Rayet star, a tumultuous orb in the last stage of evolution before it explodes in a supernova -- and event possible anytime in the next million years. Research into the spiral pattern of the emitted dust, however, indicates the we are looking nearly straight down the spin axis of the system -- possibly the same axis along which a powerful jet would emerge were the supernova accompanied by a gamma-ray burst. Now the WR 104 supernova itself will likely be an impressive but harmless spectacle. Conversely, were Earth really near the center of the powerful GRB beam, even the explosion's 8,000 light year distance might not be far enough to protect us. Currently, neither WR 104 nor GRB beams are understood well enough to know the real level of danger.

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[Ann]

Indeed, we are looking down the barrel of that rifle. Let's hope the barrel is wide enough that the bullet, when it is fired, is more likely to miss than to hit us.

Ann

[geckzilla]

The theory of punctuated equilibrium comes to mind. Should Earth be in the path of one of these events and animals survive at all, then it is all but certain there will be a lot of extra random mutations in the mix, many of them harmful but potentially some lucky few should receive beneficial ones and go on to procreate.

[Nitpicker]

For the sake of argument, if we imagine WR104 fires its jets at us directly, sometime in the next few years, say, and if we further imagine that it does so only within the precise window of a few hours around 22-23 December (when WR104 passes behind the Sun), would the Sun protect us? Either way, it might make for an extra special solstice festival that year.

[Markus Schwarz]

After looking at the picture and reading the text I wonder if the citizens of Alderaan felt the same.

[Boomer12k]

Interesting....as if we don't have enough to worry about in the Shooting Gallery we already live in.....

But....if we are irradiated...I could use an extra hand on my BACK to reach that "Hard to reach spot"....

:---[===] *

[Qev]

For the sake of argument, if we imagine WR104 fires its jets at us directly, sometime in the next few years, say, and if we further imagine that it does so only within the precise window of a few hours around 22-23 December (when WR104 passes behind the Sun), would the Sun protect us? Either way, it might make for an extra special solstice festival that year.

The Sun would be entirely opaque to a GRB, so yeah, we'd be fine under those circumstances. Now, if we were much, much further from the Sun, it would act as a gravitational lens and make the GRB's effects significantly worse.

[Qrash]

Won't the motion of our solar system around the center of the galaxy cause us to move out of the line of sight, even by a small amount in time until the supernova?

[neufer]

Won't the motion of our solar system around the center of the galaxy cause us to move out of the line of sight, even by a small amount in time until the supernova?

It is just as likely to be slowly moving us into the line of sight. (Also: WR 104's dangerous rotational pole is probably not quite aligned with the orbital axis of the spiral "pinwheel" and, hence, is probably slowly precessing.)

Click to play embedded YouTube video.

<<WR 104 is a Wolf-Rayet star discovered in 1998, located 8,000 light years from Earth. It is a binary star with an OB companion. The stars have an orbital period of 220 days and the interaction between their stellar winds produce a spiral "pinwheel" outflow pattern over 200 astronomical units long.

Some optical measurements indicate that WR 104's rotational axis is aligned within 16° of Earth. This could have potential implications to the effects of WR 104's eventual hypernova, since these explosions often produce jets from their rotational poles. It is possible that WR 104 may even produce a gamma-ray burst, though it is not possible to predict with certainty at this time. Newer spectroscopic data suggest that WR 104's rotational axis is more likely angled 30–40° from Earth.>>

[Beyond]

104, WR 104.

[neufer]

104, WR 104.

How about a little punctuation equilibrium.

[neufer]

For the sake of argument, if we imagine WR104 fires its jets at us directly, sometime in the next few years, say, and if we further imagine that it does so only within the precise window of a few hours around 22-23 December (when WR104 passes behind the Sun), would the Sun protect us?

• Ten hours of safety each year...just great
  
  You weren't thinkin' of Haydn were you

104 is the number of guns on Admiral Horatio Nelson's flagship HMS Victory.

104 is the number of Symphonies written by Joseph Haydn upon which numbers are agreed.

Click to play embedded YouTube video.

<<The greatest danger [from gamma-ray bursts in the future] is believed to come from Wolf–Rayet stars, regarded by astronomers as likely GRB candidates. When such stars transition to supernovae, they may emit intense beams of gamma rays, and if Earth were to lie in the beam zone, devastating effects may occur. Gamma rays would not penetrate Earth's atmosphere to impact the surface directly, but they would chemically damage the stratosphere. For example, if WR 104, at a distance of 8,000 light-years were to hit Earth with a burst of 10 seconds duration, its gamma rays could deplete about 25 percent of the world's ozone layer. This would result in mass extinction, food chain depletion, and starvation. The side of Earth facing the GRB would receive potentially lethal radiation exposure, which can cause radiation sickness in the short term, and in the long term result in serious impacts to life due to ozone layer depletion.>>

[Chris Peterson]

The Sun would be entirely opaque to a GRB, so yeah, we'd be fine under those circumstances. Now, if we were much, much further from the Sun, it would act as a gravitational lens and make the GRB's effects significantly worse.

No, I don't think the Sun's gravitational field could change the nature of the GRB's effects on Earth, not at any distance. All it could do is very, very slightly change the apparent direction of the source.

[Beyond]

104, WR 104.

How about a little punctuation equilibrium.

?
Bond, James Bond.

[JuanAustin]

forgive my ignorance, but if it's 8000 light years away and it went off, wouldn't it take 8000 years to reach us? if it went off 7,999 years and 364 days ago, we could get it tomorrow, right? would we feel the effects much sooner than any light based images we are looking at now or the other way around??

[Chris Peterson]

forgive my ignorance, but if it's 8000 light years away and it went off, wouldn't it take 8000 years to reach us? if it went off 7,999 years and 364 days ago, we could get it tomorrow, right? would we feel the effects much sooner than any light based images we are looking at now or the other way around??

It normally only makes sense to view time with respect to the observer. We don't care when it "really" goes off, only when the information reaches us. When we say it goes off tomorrow, what we mean is that the radiation reaches us tomorrow.

[neufer]

forgive my ignorance, but if it's 8000 light years away and it went off, wouldn't it take 8000 years to reach us? if it went off 7,999 years and 364 days ago, we could get it tomorrow, right? would we feel the effects much sooner than any light based images we are looking at now or the other way around??

We would feel the effects simultaneously with any light based images.

<<Haydn's music contains many jokes, and the Surprise Symphony includes probably the most famous of all: a sudden fortissimo chord at the end of the otherwise piano opening theme in the variation-form second movement. The music then returns to its original quiet dynamic, as if nothing had happened, and the ensuing variations do not repeat the joke. (In German it is commonly referred to as the Symphony "mit dem Paukenschlag"—"with the kettledrum stroke"). In Haydn's old age, his biographer George August Griesinger, asked him whether he wrote this "surprise" to awaken the audience. Haydn replied:

• No, but I was interested in surprising the public with something new, and in making a brilliant debut, so that my student Pleyel, who was at that time engaged by an orchestra in London (in 1792) and whose concerts had opened a week before mine, should not outdo me. The first Allegro of my symphony had already met with countless Bravos, but the enthusiasm reached its highest peak at the Andante with the Drum Stroke. Encore! Encore! sounded in every throat, and Pleyel himself complimented me on my idea.>>

[JuanAustin]

so yeah, we could feel and see the effects 5 mins from this post! thanks.

[Case]

Is there any indication of the width of such a GRB jet beam at 8,000 lightyear distance? How focused would the beam be?

[Psnarf]

Hmm, we're looking at photons that left the theater 8,000 years ago. We'd never know when the doomsday event occurred, so "Don't Worry, Be Happy!"
PS You'll recognize me as the guy in the lead suit.

Ain't futility fun? What? Me worry?!

lead.suit.jpg (20.26 KiB) Viewed 9904 times

It is in the nature of all things that take form to dissolve again.

porkypine.serious.jpg (22.8 KiB) Viewed 9904 times

[ta152h0]

don't let the Wall Street Journal writers read this stuff for surely they will grant themselves a degree in Astrophysics

[Gowron007]

Meh, at least we'll get a few hours to a few days warning of the arriving doom, thanks to neutrino detectors. Fallout irl, here we come!

[Qev]

The Sun would be entirely opaque to a GRB, so yeah, we'd be fine under those circumstances. Now, if we were much, much further from the Sun, it would act as a gravitational lens and make the GRB's effects significantly worse.

No, I don't think the Sun's gravitational field could change the nature of the GRB's effects on Earth, not at any distance. All it could do is very, very slightly change the apparent direction of the source.

Haven't there been proposals to use the Sun's gravitational field as a giant telescope lens? Not that a habitable planet could ever be that distant, since I think the focal point is out at >500 AU or something like that...

[neufer]

How focused would the beam be?

<<The approximate angular width of the jet (that is, the degree of spread of the beam) can be estimated directly by observing the achromatic "jet breaks" in afterglow light curves: a time after which the slowly decaying afterglow begins to fade rapidly as the jet slows and can no longer beam its radiation as effectively. Observations suggest significant variation in the jet angle from between 2 and 20 degrees.>>

[neufer]

Haven't there been proposals to use the Sun's gravitational field as a giant telescope lens? Not that a habitable planet could ever be that distant, since I think the focal point is out at >500 AU or something like that...

http://www.spaceroutes.com/astrocon/Ast ... roconV.pdf
http://journalogy.net/PublicationList?s ... D=21987208