APOD: SN 1006 Supernova Remnant (2014 Jul 12)

[APOD Robot]

SN 1006 Supernova Remnant

Explanation: A new star, likely the brightest supernova in recorded human history, lit up planet Earth's sky in the year 1006 AD. The expanding debris cloud from the stellar explosion, found in the southerly constellation of Lupus, still puts on a cosmic light show across the electromagnetic spectrum. In fact, this composite view includes X-ray data in blue from the Chandra Observatory, optical data in yellowish hues, and radio image data in red. Now known as the SN 1006 supernova remnant, the debris cloud appears to be about 60 light-years across and is understood to represent the remains of a white dwarf star. Part of a binary star system, the compact white dwarf gradually captured material from its companion star. The buildup in mass finally triggered a thermonuclear explosion that destroyed the dwarf star. Because the distance to the supernova remnant is about 7,000 light-years, that explosion actually happened 7,000 years before the light reached Earth in 1006. Shockwaves in the remnant accelerate particles to extreme energies and are thought to be a source of the mysterious cosmic rays.

<< Previous APOD

This Day in APOD

Next APOD >>

[/b]

[Nitpicker]

Beautiful and frightening. Is the remnant's expansion rate of about three percent of the speed of light, about typical? Does the expansion rate help to indicate anything about the original stars of the supernova?

[Boomer12k]

UM......Every Supernova Remnant has a Silver Lining?????

Interesting that there is very little..."yellow hues".....


:---[===] *

[BillBixby]

UM......Every Supernova Remnant has a Silver Lining?????

Interesting that there is very little..."yellow hues".....


:---[===] *

Also interesting, not only the small amount of yellow the human eye can see, how much red and blue the human mind has devised to see what is invisible to the eye.

I hope somebody other than me is curious as to why the long yellow horizontal line the eye can see, because I have no idea what I am seeing. I don't think another cup of coffee will unfog my mind.

[geckzilla]

Bill, check this article:
http://hubblesite.org/newscenter/archiv ... 2/image/a/

It's a shock front, which I take to be a part of the expanding shell which is running into some interstellar gas, which slows it down a little (explains the "dent" in the sphere) and also glows faintly optically.

[BillBixby]

Thank you, geck, both for the answer and the article explaining.

[starsurfer]

The entire shell is visible optically in hydrogen alpha! See here: http://iopscience.iop.org/0004-637X/585/1/324/

[somebodyshort]

I assume that at 60 light year diameter it has enveloped several stars. I also assume that as it went supernova it fried any possible life on nearby star systems.

[neufer]

I assume that at 60 light year diameter it has enveloped several stars. I also assume that as it went supernova it fried any possible life on nearby star systems.

<<One theory suggests that a Type Ia supernova would have to be closer than 10 parsecs (33 light-years) to adversely affect the Earth. On average, a supernova explosion occurs within 10 parsecs of the Earth every 240 million years. Gamma rays are responsible for most of the adverse effects a supernova can have on a living terrestrial planet. In Earth's case, gamma rays induce a chemical reaction in the upper atmosphere, converting molecular nitrogen into nitrogen oxides, depleting the ozone layer enough to expose the surface to harmful solar and cosmic radiation. Phytoplankton and reef communities would be particularly affected, which could severely deplete the base of the marine food chain. Adrian L. Melott et al. has even proposed that gamma ray bursts from a "dangerously close" supernova explosion ~444 million years ago, caused the Ordovician-Silurian extinction, which resulted in the death of nearly 60% of the oceanic life on Earth.

In 2009, researchers have found nitrates in ice cores from Antarctica at depths corresponding to the known supernovae of 1006 and 1054 CE, as well as from around 1060 CE. The nitrates were apparently formed from nitrogen oxides created by gamma rays from the supernovae. This technique should be able to detect supernovae going back several thousand years.>>

[neufer]

The entire shell is visible optically in hydrogen alpha!
See here: http://iopscience.iop.org/0004-637X/585/1/324/

The entire shell is visible optically in hydrogen alpha in this APOD if one looks carefully enough (at the yellow).

[DavidLeodis]

Bill, check this article:
http://hubblesite.org/newscenter/archiv ... 2/image/a/

It's a shock front, which I take to be a part of the expanding shell which is running into some interstellar gas, which slows it down a little (explains the "dent" in the sphere) and also glows faintly optically.

Thanks geckzilla for that explanation as I was also wondering about the yellow filament.

According to the CXC release that is brought up through the explanation's "this composite view" link the yellow in the image is optical data acquired by the CTIO, but I'm unsure if I am interpreting that correctly in regard to the yellow filament. I appreciate that there would not be room in a short explanation to give information about everything in this APOD but it is odd that the explanation does not directly mention the very obvious yellow filament. Why for example is it only a short length (relatively speaking compared to the rest of the sphere's circumference)

[Chris Peterson]

I assume that at 60 light year diameter it has enveloped several stars. I also assume that as it went supernova it fried any possible life on nearby star systems.

The gas we're seeing here represents a very good vacuum- probably better than we can achieve in a laboratory. If you lived in a nearby star system, you wouldn't even be aware it was passing you (although as Art notes, the initial radiation burst could be a big problem if you were within a few parsecs).

[geckzilla]

Why for example is it only a short length (relatively speaking compared to the rest of the sphere's circumference)

Once a ball of gas starts expanding and it's not held in shape by gravity then anything nearby can easily put dents in it or blow it into a very different shape. This is some special ionized hydrogen getting scrunched up on one side. What's it running into? I don't know if it's the hydrogen itself just chillin' out in space and getting blasted by the supernova or if some of it came out of the supernova itself and then ran into a denser part of space. I guess the important thing to take away is that space is mostly empty but just a few extra atoms of stuff here and there mean we don't see a lot of perfect spheres.

[DavidLeodis]

Why for example is it only a short length (relatively speaking compared to the rest of the sphere's circumference)

Once a ball of gas starts expanding and it's not held in shape by gravity then anything nearby can easily put dents in it or blow it into a very different shape. This is some special ionized hydrogen getting scrunched up on one side. What's it running into? I don't know if it's the hydrogen itself just chillin' out in space and getting blasted by the supernova or if some of it came out of the supernova itself and then ran into a denser part of space. I guess the important thing to take away is that space is mostly empty but just a few extra atoms of stuff here and there mean we don't see a lot of perfect spheres.

Thanks geckzilla.

I wonder if the Universe is a perfect sphere?

[Chris Peterson]

I wonder if the Universe is a perfect sphere?

Any visible universe is very close to a sphere, but not a perfect one since gravity has influenced the expansion of space. The Universe is not a three-dimensional structure, so it can't be a sphere (although it may be the four-dimensional analog of a sphere).

[geckzilla]

I was just about to ask if it was safe to assume the visible universe is a sphere. Oh, you answered the question before I could even type it.

[Ann]

Geck wrote:
I guess the important thing to take away is that space is mostly empty but just a few extra atoms of stuff here and there mean we don't see a lot of perfect spheres.

There are some pretty good spheres out there, though. This one is a planetary nebula, not a supernova remnant, so it was created in a gentler way.

Ann

[geckzilla]

Yeah. I'm partial to the lemon slice, myself. There are some very cool rings, tubes, cones, and hourglass shapes that are nearly perfect geometrical structures formed by dying stars, too. It's probably a lot easier to form nice shapes on a smaller scale like that. Less of a chance to get messed with, assuming the start wasn't already messy to begin with. Planetaries are some of the most complicated nebulas out there.

[DavidLeodis]

Thanks all for your responses, which are appreciated.

I hope my layman's thoughts are considered worthy of asking. For example, I understand that the Universe may be expanding faster than the speed of light. If so I wonder what will happen if the Universe starts to contract faster than the speed of light and thus light travelling out can catch up so to speak. I visualise a scene where all the light that has ever been (even will be) meets the boundary of the shrinking Universe and displays as a beautiful collected aurora of light!

[Chris Peterson]

I understand that the Universe may be expanding faster than the speed of light.

That assertion is a little unclear. Because the Universe is expanding uniformly, the speed that any two points are separating from each other increases with the distance between them. Consequently, once points are sufficiently far apart, they are separating at greater than c.

If so I wonder what will happen if the Universe starts to contract faster than the speed of light and thus light travelling out can catch up so to speak.

But that's not going to happen. The rate of expansion is increasing due to the effects of dark energy. There will be no contraction.

[starsurfer]

The entire shell is visible optically in hydrogen alpha!
See here: http://iopscience.iop.org/0004-637X/585/1/324/

The entire shell is visible optically in hydrogen alpha in this APOD if one looks carefully enough (at the yellow).

I can only see the bright filament in optical in the image.

It would be awesome if Don Goldman took a deep image of this next year!