by BDanielMayfield » Sat Dec 29, 2012 10:48 pm
neufer wrote:Boomer12k wrote:
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.
http://en.wikipedia.org/wiki/Zeta_Ophiuchi wrote:
<<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.>>
http://en.wikipedia.org/wiki/Scorpius-Centaurus_Association wrote:
<<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
[quote="neufer"][float=right][img3="[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]"]http://media.eurekalert.org/multimedia_prod/pub/web/1499_web.jpg[/img3][/float][quote="Boomer12k"]
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.[/quote]
After ~40,000 years there is not much left of a [url=http://apod.nasa.gov/apod/ap121009.html]supernova remnant[/url] to observe and we would likely be [u]inside of any remnant this close[/u]. One must look rather for pulsars. :arrow:
[quote=" http://en.wikipedia.org/wiki/Zeta_Ophiuchi"]
<<ζ Ophiuchi is moving through space with a peculiar velocity of 30 km/s. [b][color=#0000FF]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.[/color][/b] 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.[b][color=#0000FF] 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.[/color][/b]>>[/quote][quote=" http://en.wikipedia.org/wiki/Scorpius-Centaurus_Association"]
[float=right][img3=""]http://upload.wikimedia.org/wikipedia/commons/thumb/f/fe/Sco-CenMap.png/720px-Sco-CenMap.png[/img3][/float]
<<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. [b][color=#0000FF]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 [sup]60[/sup]Fe in deep ocean ferromanganese crusts, it has been hypothesized that a nearby supernova, [u]possibly a member of Sco-Cen[/u], exploded in the Sun's vicinity roughly 3 million years ago.[/color][/b]>>[/quote][/quote]
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