APOD: Zeta Oph: Runaway Star (2012 Dec 29)

[ta152h0]

This must be voted APOD of the Year. The Big Poobah in the Sky has to be proud of his creation. Hey Charlie Brown, there is a Great Pumpkin

[BDanielMayfield]

[b][color=#FF0000]The faint pulsar PSR B1929+10 captured by the unrivalled sensitivity of ESAs XMM-Newton orbiting X-ray observatory. It is speeding through space in the direction of the arrow at a speed of 177 kilometres per second. At this speed, the pulsar leaves a trail of X-ray emitting electron plasma stretching across space. Credit: Image: Werner Becker / MPI for Extraterrestrial Physics[/color][/b]

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I don't see a supernova remnant anywhere nearby... The other could now be a small dwarf star, or even a black hole and traveling along too close to see maybe, or it just got blown away, and then Zeta Oph would just have "continued on its way". But I don't see an S.R. anywhere nearby, and I suppose it could be obscured by denser dust in another part of the nebulosity.

After ~40,000 years there is not much left of a supernova remnant to observe and we would likely be inside of any remnant this close. One must look rather for pulsars.

<<ζ Ophiuchi is moving through space with a peculiar velocity of 30 km/s. Based upon the age and direction of motion of this star, it is a member of the Upper Scorpius sub-group of the Scorpius-Centaurus Association of stars that share a common origin and space velocity. Such runaway stars may be ejected by dynamic interactions between three or four stars. However, in this case the star may be a former component of a binary star system in which the more massive primary was destroyed in a Type II supernova explosion. The pulsar PSR B1929+10 may be the leftover remnant of this supernova, as it too was ejected from the association with a velocity vector that fits the scenario.>>

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<<The Scorpius-Centaurus Association (sometimes called Sco-Cen or Sco OB2) is the nearest OB Association to the Sun. This stellar association is composed of three subgroups (Upper Scorpius, Upper Centaurus-Lupus, and Lower Centaurus-Crux), whose mean distances range from 380 to 470 light years.

Many of the bright stars in the constellations Scorpius, Lupus, Centaurus, and Crux are members of the Sco-Cen association, including Antares (the most massive member of Upper Scorpius), and most of the stars in the Southern Cross. The Sco-Cen OB association appears to be the most pronounced part of a large complex of recent (<20 million years) and ongoing star-formation. The complex contains several star-forming molecular clouds in Sco-Cen's immediate vicinity—the Rho Oph, Pipe Nebula, Barnard 68, Chamaeleon, Lupus, Corona Australis, and Coalsack cloud complexes (all at distances of ~120-200 parsecs), and several less populous, young stellar groups on the periphery of Sco-Cen, including the ~3-5 million-year-old epsilon Cha group, ~7 million-year-old eta Chamaeleontis cluster (also called Mamajek 1), ~8 million-year-old TW Hydrae association, ~12 million-year-old Beta Pictoris moving group, and possibly the ~30-50 million-year-old IC 2602 open cluster.

The stellar members of the Sco-Cen association have convergent proper motions of approximately 0.02-0.04 arcseconds per year, indicative that the stars have nearly parallel velocity vectors, moving at about 20 km/s with respect to the Sun. The dispersion of the velocities within the subgroups are only of order 1–2 km/s, and the group is most likely gravitationally unbound. Several supernovae have exploded in Sco-Cen over the past 15 million years, leaving a network of expanding gas superbubbles around the group, including the Loop I Bubble. To explain the presence of radioactive ⁶⁰Fe in deep ocean ferromanganese crusts, it has been hypothesized that a nearby supernova, possibly a member of Sco-Cen, exploded in the Sun's vicinity roughly 3 million years ago.>>

That’s a fascinating tidbit that you highlight at the end of your very informitive post, neufer. We are made from the dust of the earth, but the dust of the earth was made from star stuff, as Sagan was fond of saying. It seems very possible and perhaps likely that the supernova blast that sent today’s apod star flying upon its runaway path around 3 million years ago is the very one that dusted the earth with enough “star stuff” that it can still be measured today in sediments at the bottom of the seas. If this is the case then it would be very likely that most and maybe all humans alive today have at least a few and maybe even many atoms from this supernova inside our bodies right now. I think this puts today’s apod in a more personal perspective than most, don’t you think?

I'm glad that Zeta Oph is a naked eye star that will be so easy to find right above the great Scorpion and to the right of the tea pot asterism that helps me find the center of the Milky Way. Today's Apod and what I have learned about Zeta Oph will contribute to my star gazing enjoyment for many nights to come, I am sure.

Bruce

[neufer]

That’s a fascinating tidbit that you highlight at the end of your very informative post, neufer. We are made from the dust of the earth, but the dust of the earth was made from star stuff, as Sagan was fond of saying. It seems very possible and perhaps likely that the supernova blast that sent today’s apod star flying upon its runaway path around 3 million years ago is the very one that dusted the earth with enough “star stuff” that it can still be measured today in sediments at the bottom of the seas. If this is the case then it would be very likely that most and maybe all humans alive today have at least a few and maybe even many atoms from this supernova inside our bodies right now. I think this puts today’s apod in a more personal perspective than most, don’t you think?

And what if it also caused critical mutations to our DNA that led to Homo habilis.
http://en.wikipedia.org/wiki/Human_accelerated_regions

[bboyne3]

Dear APOD,

I do not know if you photoshop, but I see a gorgeous woman who is now my screen saver.

regards,

bill

[BDanielMayfield]

And what if it also caused critical mutations to our DNA that led to ...

I respectfully disagree with that speculative suggestion, since I’m personally convinced that our appearance as a species was intentional rather than accidental. That being said, I have no reason to disbelieve that a relatively nearby supernova occurred about 3 MYA, or that it could have had a significant effect upon this planet and the life upon it. I wonder, is there any evidence of paleio-climatic changes or is there any fossil evidence for any changes on the earth around this time?

Bruce

[Ann]

And what if it also caused critical mutations to our DNA that led to ...

I respectfully disagree with that speculative suggestion, since I’m personally convinced that our appearance as a species was intentional rather than accidental. That being said, I have no reason to disbelieve that a relatively nearby supernova occurred about 3 MYA, or that it could have had a significant effect upon this planet and the life upon it. I wonder, is there any evidence of paleio-climatic changes or is there any fossil evidence for any changes on the earth around this time?

Bruce

You should probably ask someone else, but I strongly believe that the supernova that sent Zeta Ophiuchi flying happened too far away to really affect the Earth. According to my software, the distance to Zeta Ophiuchi today is 366 ± 8 light-years, clearly suggesting that the distance is not greater than 400 light-years. The other stars of upper Scorpius, however, appear to be typically at least 500 light-years away. It would appear, therefore, that the runaway Zeta Ophiuchi might be approaching us, so that it was farther away than it is now by the time its companion went supernova. Anyway, a distance of about 400 light-years is probably quite safe for a Type II supernova.

On the other hand, I believe that astronomers think that the solar system was born from a gas cloud that had been enriched by elements from a recent supernova. So we are indeed the children of supernovae.

Ann

[BDanielMayfield]

And what if it also caused critical mutations to our DNA that led to ...

I respectfully disagree with that speculative suggestion, since I’m personally convinced that our appearance as a species was intentional rather than accidental. That being said, I have no reason to disbelieve that a relatively nearby supernova occurred about 3 MYA, or that it could have had a significant effect upon this planet and the life upon it. I wonder, is there any evidence of paleio-climatic changes or is there any fossil evidence for any changes on the earth around this time?

Bruce

You should probably ask someone else, but I strongly believe that the supernova that sent Zeta Ophiuchi flying happened too far away to really affect the Earth. According to my software, the distance to Zeta Ophiuchi today is 366 ± 8 light-years, clearly suggesting that the distance is not greater than 400 light-years. The other stars of upper Scorpius, however, appear to be typically at least 500 light-years away. It would appear, therefore, that the runaway Zeta Ophiuchi might be approaching us, so that it was farther away than it is now by the time its companion went supernova. Anyway, a distance of about 400 light-years is probably quite safe for a Type II supernova.

On the other hand, I believe that astronomers think that the solar system was born from a gas cloud that had been enriched by elements from a recent supernova. So we are indeed the children of supernovae.

Ann

Ann, first let me correct my failure to thank you for that detailed answer you provided to one of my initial questions in this thread. After reading what you wrote I can see now that estimating the power of the future blast of Zeta Oph when it goes SN would be fraught with much uncertainty.

As the discussion progressed however I became much more interested in the past rather than the future with regard to this star and its one time binary companion. The reason for this can be found in the Wikipedia article on Zeta Ophuichi (I apologize for not providing a link). In this article you will find that the radial velocity of this star is listed as negative 15 km/s. Therefore this star is found to be rapidly receding, and not approaching as you suggested in your last comment. So this is good news for anything living on earth in the 4 or so million years when it follows the fate of its former partner.

So the question then becomes how close may the SN that launched Zeta Oph have been to the earth 3 MYA? As you state the distance to Zeta Oph now is about 366 ly. The above referenced Wiki article also lists it’s peculiar (that is actual) velocity as being 30 km/s. Multiplying that by 3 MYA yields approximately 300 ly. So we have two sides of an irregular triangle and if we can estimate the angle between these lines we can then calculate the estimated distance between where the earth is now and where Zeta Oph was 3 MYA when its companion popped.

The Wiki article also lists the proper motions in Right Ascension and in Declination as being +15.26 and +24.79 in milliarcseconds per year. Someone with somewhat more math skills and or time than I should be able to do the calculation with this set of givens, I would think. Once we have solved for the distance stated in the last sentence of my previous paragraph then we would simply need to account for the sun’s motion backwards 3 MYA and we would then have a fairly good answer as to how far away from earth this SN was. I can not imagine that this hasn’t already been done, since even someone like me can conceive of how to arrive at the solution.

In short though Ann, since Zeta Oph is receding from us, I do think that the SN that launched it could indeed have been the one that nuefer referenced. If so then you and I and likely everyone else as well as this runaway star share atoms that were created in this supernova blast, which I think is a very nice connection.

Bruce

[ta152h0]

maybe a hypernovae ????? a really big kaboom like the Big Bang and this star has been traveling ever since, in various forms ? or not !

[Raven]

...a really big kaboom like the Big Bang and this star has been traveling ever since, in various forms ?

gypsy of a strange and distant time
traveling in panic, all direction blind ...
oh oh, oh oh oh oh oh oh
oh oh, oh oh oh oh oh oh
left without a hope of coming home

-- Justin Hayward / Moody Blues