APOD: Recycling Cassiopeia A (2021 Jan 23)

[APOD Robot]

Recycling Cassiopeia A

Explanation: Massive stars in our Milky Way Galaxy live spectacular lives. Collapsing from vast cosmic clouds, their nuclear furnaces ignite and create heavy elements in their cores. After a few million years, the enriched material is blasted back into interstellar space where star formation can begin anew. The expanding debris cloud known as Cassiopeia A is an example of this final phase of the stellar life cycle. Light from the explosion which created this supernova remnant would have been first seen in planet Earth's sky about 350 years ago, although it took that light about 11,000 years to reach us. This false-color image, composed of X-ray and optical image data from the Chandra X-ray Observatory and Hubble Space Telescope, shows the still hot filaments and knots in the remnant. It spans about 30 light-years at the estimated distance of Cassiopeia A. High-energy X-ray emission from specific elements has been color coded, silicon in red, sulfur in yellow, calcium in green and iron in purple, to help astronomers explore the recycling of our galaxy's star stuff. Still expanding, the outer blast wave is seen in blue hues. The bright speck near the center is a neutron star, the incredibly dense, collapsed remains of the massive stellar core.

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[Sérgio]

Túnel de laser pode facilitar o impulso da nave para sair da terra ou viajar mais rápido no espaço.

[Sérgio]

Um raio puxa ou empura ?

[VictorBorun]

Click to view full size image

Is there another cannonball overrunning the shock front?
And by the way does its trail point slightly to the left and below as if the neutron star shifted slightly to the right and up since the moment of the SN explosion?

[VictorBorun]

Click to view full size image

All the lines I think I can see have a common point and the neutron star (see the red ring) is off that common point.

Suppose that common point of all the lines is the center of the Supernova explosion.
Then the shock front ball (shown in blue) is not centered on it.
Maybe there is more dense interstellar gas in the bottom half of the picture, and it slows the shock wave?

All the lines I draw don't look like an edgehog, a bunch of tracks with a zero sum of momenta.
But then we don't know if each of the tracks is perpendicular to our line of sight or at an angle.

Large white and yellow (sulphur) ring may be a porthole made in the shock sphere by a cannonball flying almost toward us. I draw the ring (in red) and the center is to the right and up from the common point of all the lines. So I draw in red a line for this cannonball too though I can't see it at all.

[Ann]

Click to view full size image

All the lines I think I can see have a common point and the neutron star (see the red ring) is off that common point.

Suppose that common point of all the lines is the center of the Supernova explosion.
Then the shock front ball (shown in blue) is not centered on it.
Maybe there is more dense interstellar gas in the bottom half of the picture, and it slows the shock wave?

All the lines I draw don't look like an edgehog, a bunch of tracks with a zero sum of momenta.
But then we don't know if each of the tracks is perpendicular to our line of sight or at an angle.

Large white and yellow (sulphur) ring may be a porthole made in the shock sphere by a cannonball flying almost toward us. I draw the ring (in red) and the center is to the right and up from the common point of all the lines. So I draw in red a line for this cannonball too though I can't see it at all.

Interesting, Victor. I agree with you that something has broken through the "shell" of the supernova remnant at about 10 o'clock. It is a known fact that neutron stars and even black holes can get a kick during a supernova explosion so that they get sent flying.

I also agree that the red ring you have circled is the neutron star that was left behind after the explosion. At least I think we have to interpret the wording of the caption that way.

Ann

[orin stepanek]

Just showing the picture; I guess I'm missing the cannonball! I do
see the straight line from the center but have no means of identifying
what ever it is; probably a projectile from the star!

[neufer]

Cassiopeia A was the first light image of the Chandra X-ray Observatory

---

Click to play embedded YouTube video.

NASA Unveils First Images From Chandra X-Ray Observatory
August 26, 1999

<<Extraordinary first images from NASA's Chandra X-ray Observatory trace the aftermath of a gigantic stellar explosion in such stunning detail that scientists can see evidence of what may be a neutron star or black hole near the center.

"When I saw the first image, I knew that the dream had been realized," said Dr. Martin Weisskopf, Chandra Project Scientist, NASA's Marshall Space Flight Center, Huntsville, AL. "This observatory is ready to take its place in the history of spectacular scientific achievements."

"We were astounded by these images," said Harvey Tananbaum, Director of the Smithsonian Astrophysical Observatory's Chandra X- ray Center, Cambridge, MA. "We see the collision of the debris from the exploded star with the matter around it, we see shock waves rushing into interstellar space at millions of miles per hour, and, as a real bonus, we see for the first time a tantalizing bright point near the center of the remnant that could possibly be a collapsed star associated with the outburst."

After the telescope's sunshade door was opened last week, one of the first images taken was of the 320-year-old supernova remnant Cassiopeia A, which astronomers believe was produced by the explosion of a massive star. Material blasted into space from the explosion crashed into surrounding material at 10 million miles per hour. This collision caused violent shock waves, like massive sonic booms, creating a vast 50-million degree bubble of X-ray emitting gas.

Heavy elements in the hot gas produce X-rays of specific energies. Chandra's ability to precisely measure these X-rays tells how much of each element is present. With this information, astronomers can investigate how the elements necessary for life are created and spread throughout the galaxy by exploding stars.>>

<<In 2013, astronomers detected phosphorus in Cassiopeia A, which confirmed that this element is produced in supernovae as a byproduct of supernova nucleosynthesis. The phosphorus-to-iron ratio in material from the supernova remnant could be up to 100 times higher than in the Milky Way in general.

In 2020, astronomers analysed ALMA and ROSINA data from the massive star-forming region AFGL 5142, to detect phosphorus-bearing molecules, and how they are carried in comets to the early Earth. Phosphorus is essential for life. [Almost 99% of the mass of the human body is made up of six elements: hydrogen (H), carbon (C), nitrogen (N), oxygen (O), calcium (Ca), and phosphorus (P) (CHNOPS for short).] Phosphates (compounds containing the phosphate ion, PO₄³⁻) are a component of DNA, RNA, ATP, and phospholipids. Elemental phosphorus was first isolated from human urine, and bone ash was an important early phosphate source. Phosphate mines contain fossils because phosphate is present in the fossilized deposits of animal remains and excreta. Low phosphate levels are an important limit to growth in some aquatic systems. The vast majority of phosphorus compounds mined are consumed as fertilisers. Phosphate is needed to replace the phosphorus that plants remove from the soil, and its annual demand is rising nearly twice as fast as the growth of the human population. Other applications include organophosphorus compounds in detergents, pesticides, and nerve agents.

Phosphorus has a concentration in the Earth's crust of about one gram per kilogram. It is not found free in nature, but is widely distributed in many minerals, usually as phosphates. Inorganic phosphate rock, which is partially made of apatite (a group of minerals being, generally, pentacalcium triorthophosphate fluoride (hydroxide)), is today the chief commercial source of this element. Organic sources, namely urine, bone ash and (in the latter 19th century) guano, were historically of importance but had only limited commercial success. As urine contains phosphorus, it has fertilising qualities which are still harnessed today in some countries, including Sweden, using methods for reuse of excreta. To this end, urine can be used as a fertiliser in its pure form or part of being mixed with water in the form of sewage or sewage sludge. >>

[bystander]

Elementary Nature of Cassiopeia A
Chandra X-ray Observatory | 2017 Dec 12

16 pointings between Jan 2000 - Nov 2010 ~ Credit: NASA/CXC/SAO

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Latest Look at "First Light" from Chandra
Chandra X-ray Observatory | 2019 Aug 26

Hubble data 2004-2011 ~ Credit: NASA/STScI

---

[johnnydeep]

Recycling Cassiopeia A

Explanation: Massive stars in our Milky Way Galaxy live spectacular lives. Collapsing from vast cosmic clouds, their nuclear furnaces ignite and create heavy elements in their cores. After a few million years, the enriched material is blasted back into interstellar space where star formation can begin anew. The expanding debris cloud known as Cassiopeia A is an example of this final phase of the stellar life cycle. Light from the explosion which created this supernova remnant would have been first seen in planet Earth's sky about 350 years ago, although it took that light about 11,000 years to reach us. This false-color image, composed of X-ray and optical image data from the Chandra X-ray Observatory and Hubble Space Telescope, shows the still hot filaments and knots in the remnant. It spans about 30 light-years at the estimated distance of Cassiopeia A. High-energy X-ray emission from specific elements has been color coded, silicon in red, sulfur in yellow, calcium in green and iron in purple, to help astronomers explore the recycling of our galaxy's star stuff. Still expanding, the outer blast wave is seen in blue hues. The bright speck near the center is a neutron star, the incredibly dense, collapsed remains of the massive stellar core.

So, let's see, the debris expanded 15 ly from the center in 350 years, which means the material traveled at 15/350*100 = 4.3% c, do I have that right?

[DL MARTIN]

Am I wrong to conclude a degree of subjectivity regarding the absence of conjecture on what has taken place in Cassiopeia A during the intervening 11,000 years? Surely the 350 year window of observation doesn't define totality!

[Chris Peterson]

Am I wrong to conclude a degree of subjectivity regarding the absence of conjecture on what has taken place in Cassiopeia A during the intervening 11,000 years?

Yes. All that matters is that we're looking at a 350 year old structure.

[MarkBour]

Art (neufer) --

Thanks for sharing this relevant work from Wikipedia. I was happy to gain some of this additional learning. I do have a question about the sourcing here, though. I think you did a little cutting and pasting. I'm referring to your second citation of: https://en.wikipedia.org/wiki/Phosphorus#Universe .

The part I have put a border around below is not in that article in that place.

. . .

I point this out, not to criticize, but because I was trying to figure out something in that citation. So, on further investigation, I see that almost everything in that boxed portion did come from the very same Wikipedia article, just earlier in the article than the rest. The first sentence, and also the third sentence and everything after it are in that Wikipedia article, up in the opening section of it. No problem.

That leaves the second sentence in that boxed part. I now see that you had marked this sentence as an insert; it has square brackets around it. So, the sentence in question is:

[Almost 99% of the mass of the human body is made up of six elements: hydrogen (H), carbon (C), nitrogen (N), oxygen (O), calcium (Ca), and phosphorus (P) (CHNOPS for short).]

Sure enough, though, that was the sentence that had given me pause. Here's a revision of it:

https://socratic.org/questions/548f1e30581e2a6c73538706

What does CHNOPS stand for?
Biology
1 Answer

Johnny L. · Media Owl
Dec 15, 2014
The acronym CHNOPS is often used to remember the 6 most common elements in living things: carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur. The first four of those (C, H, N, and O) are more common than the last two (P and S), so that's the simple answer to your question.

Since all life (or almost all life) is organically based, carbon is incredibly abundant in living things. Its flexible bonding allows it to make many types of molecules, including macromolecules like carbohydrates, proteins, lipids, and nucleic acids. Nitrogen is present in proteins, which make up a large percentage of the solid material of organisms' bodies. Hydrogen and oxygen are present in many macromolecules as well as being the constituents of water.

capture.gif (8.39 KiB) Viewed 9041 times

So the CHNOPS acronym lists the most common elements for Earth life in general, and the S is for Sulfur. However, the list of top elements in the human body is slightly different. The top elements in the human body (by number of atoms
-- not mass) are: Hydrogen, Oxygen, Carbon, Nitrogen, Calcium, and Phosphorus. For humans, Sulfur is a distant 7th, closely followed in abundance by Sodium and Potassium, then in smaller amounts Chlorine and Magnesium, and then "trace" elements.

So, again, your inserted statement about the top 6 elements in the human body is correct, and they do comprise over 99% of the atoms and over 98% of the mass. (They just don't match the CHNOPS acronym.)

So ends my long-winded quibble.

[neufer]

So, let's see, the debris expanded 15 ly from the center in 350 years,
which means the material traveled at 15/350*100 = 4.3% c, do I have that right?

• Yes.

Am I wrong to conclude a degree of subjectivity regarding the absence of conjecture
on what has taken place in Cassiopeia A during the intervening 11,000 years?

Yes. All that matters is that we're looking at a 350 year old structure.

• I think Chris misunderstands DL MARTIN's word salad inquiry.

Perhaps I can interest "DL MARTIN" in a ~11,000 year old supernova remnant only 800 light-years away:

• https://apod.nasa.gov/apod/ap080306.html
  https://apod.nasa.gov/apod/ap070213.html
  https://apod.nasa.gov/apod/ap131001.html

Click to play embedded YouTube video.

Long exposure of the northern section of the Vela Supernova Remnant, taken from the Kalahari Desert in Namibia. This image shows the supernova remnant's northern section. The location of the Vela Pulsar, which is the origin of the supernova remnant, is approximately indicated by the annotation.

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<<When the supernova remnant slows to the speed of the random velocities in the surrounding medium, after roughly 30,000 years, it will merge into the general turbulent flow, contributing its remaining kinetic energy to the turbulence.

The Vela supernova remnant is a supernova remnant in the southern constellation Vela. Its source Type II supernova exploded approximately 11,000–12,300 years ago (and was about 800 light-years away). The association of the Vela supernova remnant with the Vela pulsar, made by astronomers at the University of Sydney in 1968, was direct observational evidence that supernovae form neutron stars.

The Vela supernova remnant includes NGC 2736. It also overlaps the Puppis A supernova remnant, which is four times more distant. Both the Puppis and Vela remnants are among the largest and brightest features in the X-ray sky.

The Vela supernova remnant (SNR) is one of the closest known to us. The Geminga pulsar is closer (and also resulted from a supernova), and in 1998 another near-Earth supernova remnant was discovered, RX J0852.0-4622, which from our point of view appears to be contained in the southeastern part of the Vela remnant. One estimate of its distance puts it only about 650 ly, closer than the Vela remnant, and, surprisingly, it seems to have exploded much more recently, in the last thousand years, because it is still radiating gamma rays from the decay of titanium-44. This remnant was not seen earlier because in most wavelengths, it is lost because of the presence of the Vela remnant.>>

[MarkBour]

Recycling Cassiopeia A

Explanation: Massive stars in our Milky Way Galaxy live spectacular lives. Collapsing from vast cosmic clouds, their nuclear furnaces ignite and create heavy elements in their cores. After a few million years, the enriched material is blasted back into interstellar space where star formation can begin anew. The expanding debris cloud known as Cassiopeia A is an example of this final phase of the stellar life cycle. Light from the explosion which created this supernova remnant would have been first seen in planet Earth's sky about 350 years ago, although it took that light about 11,000 years to reach us. This false-color image, composed of X-ray and optical image data from the Chandra X-ray Observatory and Hubble Space Telescope, shows the still hot filaments and knots in the remnant. It spans about 30 light-years at the estimated distance of Cassiopeia A. High-energy X-ray emission from specific elements has been color coded, silicon in red, sulfur in yellow, calcium in green and iron in purple, to help astronomers explore the recycling of our galaxy's star stuff. Still expanding, the outer blast wave is seen in blue hues. The bright speck near the center is a neutron star, the incredibly dense, collapsed remains of the massive stellar core.

So, let's see, the debris expanded 15 ly from the center in 350 years, which means the material traveled at 15/350*100 = 4.3% c, do I have that right?

I agree. (Well, my calculator does.) The material is creating a shock wave as it encounters other material, and this interaction is probably how we can see it -- because it is heated and radiates from that.

From the Wikipedia article: "Supernova Remnant": https://en.wikipedia.org/wiki/Supernova_remnant

... the resulting supernova explosion expels much or all of the stellar material with velocities as much as 10% the speed of light (or approximately 30,000 km/s). These speeds are highly supersonic, so a strong shock wave forms ahead of the ejecta. That heats the upstream plasma up to temperatures well above millions of K. The shock continuously slows down over time as it sweeps up the ambient medium, but it can expand over hundreds or thousands of years and over tens of parsecs before its speed falls below the local sound speed.

Over the course of just 350 years, I don't know that there has been an appreciable slowing, so your constant-velocity estimate seems reasonable.

[neufer]

So the CHNOPS acronym lists the most common elements for Earth life in general, and the S is for Sulfur.

However, the list of top elements in the human body is slightly different. The top elements in the human body (by number of atoms
-- not mass) are: Hydrogen, Oxygen, Carbon, Nitrogen, Calcium, and Phosphorus. For humans, Sulfur is a distant 7th, closely followed in abundance by Sodium and Potassium, then in smaller amounts Chlorine and Magnesium, and then "trace" elements.

So, again, your inserted statement about the top 6 elements in the human body is correct, and they do comprise over 99% of the atoms and over 98% of the mass. (They just don't match the CHNOPS acronym.)

So ends my long-winded quibble.

• HOCNCP is simply the sound one makes from drinking too much CHNOPS:
  https://www.popularmechanics.com/space/ ... hosphorus/
  https://www.nature.com/articles/s41467-020-17649-9

Click to play embedded YouTube video.

<<Schnapps or schnaps is a type of alcoholic beverage that may take several forms, including distilled fruit brandies, herbal liqueurs, infusions, and "flavored liqueurs" made by adding fruit syrups, spices, or artificial flavorings to neutral grain spirits.

The English loanword "schnapps" is derived from the colloquial German word Schnaps (plural: Schnäpse) which is used in reference to spirit drinks. The word Schnaps stems from Low German language and is related to the German term "schnappen", meaning "snap" or "snatch" which refers to the fact that the spirit is usually consumed in a quick slug from a small glass (i.e., a shot glass). In British English, a corresponding term is "dram" [of liquor].>>

[MarkBour]

• HOCNCP is simply the sound one makes from drinking too much CHNOPS:
  
  CHOrtle !

[DL MARTIN]

Thanks to all for the response to my query as to what happens after the 350 year period. I'm not sure that I agree that nothing is of concern after what we see. Are we not ignoring an evolutionary transition?

[MarkBour]

Elementary Nature of Cassiopeia A
Chandra X-ray Observatory | 2017 Dec 12

16 pointings between Jan 2000 - Nov 2010 ~ Credit: NASA/CXC/SAO

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Thank you for sharing this, bystander. From the APOD image, I was wondering why it seemed that iron had mainly been ejected just in one large clump in a single direction. You images helped me see that the iron (and all of the elements) were more evenly distributed than I could see just from the APOD image itself. And all of the ejecta are essentially spherically symmetric in their dispersal, as would make sense.

But my wondering about it remains.

When something the size of a star comes to its end, how can it explode in such a way that the distribution of its heavy elements is not a relatively smooth and homogeneous sphere? How could the dynamics result in releasing iron in three large portions of much higher density than the rest of the sphere? It would make some sense to me that the dynamics might cause it to be ejected in a band, rather than the whole sphere (for example, the rotational component of the star's motion might cause the iron to come out mostly towards the equator). But your image of the iron detected makes it look like a bomb of the size humans might make, having exploded and broken into 3 primary parts. All of the elements shown in your images are those that would have formed deep in the heart of the star before it exploded. But if they begin as a shell of material in a sphere of very large size, then when they are expelled, it is hard for me to imagine what might cause them to be so unevenly distributed in the ejecta.

As I look at it a little longer, I perceive that all 4 of your elemental images show this unevenness, and the higher-concentration regions of all of those elements mostly coincide. It is most pronounced in iron and almost as pronounced in calcium. The order of mass of these elements from highest to lowest, is: Iron (56), Calcium (40), Sulfur (32), and Silicon (28). So the heavier the element, the more unevenly it appears distributed in your images.

Is it possible that this star ripped apart into 3 main parts as it exploded? Or is there another explanation? Perhaps it was very uniform, but we only see these elements in parts of the sphere. Maybe those parts had the most material to run into on the way out of the center, so they are lighting up the most. (?)

As such an explosion occurs, is it believed that the heavier elements are ejected more slowly than the lighter ones? Or is it sensible that at least they are not as prevalent in the leading edge of the shock wave, so they are producing less radiation for us to see?

[VictorBorun]

Click to view full size image

What if an SN explosion throws around several of magnetic dinamo cannonball bodies, each travelling at a constant velocity through interstellar gas and in time overrunning the shock front sphere and making a porthole in it the size of the magnetic halo of the cannonball?

It looks like the shock front sphere has large portholes centered around cannonballs' trails overunning the the shock front.
The brightest trail belong to a pair of cannonballs at 10 o'clock which are also the fastest. Their porthole frames we see edge-on like rectangular view of a cylinder wall.

The largest porthole though we see face-on and I can't see any trail ending at the center of this porthole. Maybe it's sort of an anti-jet, a shadow cast by a close companion body inside SN when another body inside SN collapsed and produced the heat? If the cold body was massive it would have stood still and we can't see it now.

[VictorBorun]

Click to view full size image

I think I can see a shadow cone with its axis at 11 o'clock.

If it is real and was casted by a massive cold body close to the point of the SN expolsion, then this cone can not hold cannonball trails. Therefore the pair of cannonballs must flow in the plane of the picture or somewhat away from us while the shadow cone must expand in our half-space of the picture's plane.

We can see some blue spots of the shock front in the area I drew for the shadow cone. But they all may belong to the far side of the shock front sphere, can't they?

[TheZuke!]

"Collapsing from vast cosmic clouds, their nuclear furnaces ignite and create heavy elements in their cores. "

I'm a bit puzzled by this sentence in the description.

It has been my (newbie) understanding that "heavy elements" are created not during the ignition/burning phase of the star's "life", but only during the immense pressure of its fatal implosion.

Unless? Iron is a "heavy element"?

Relativity... Iron is heavy if dropped and lands on my toes.

[Chris Peterson]

"Collapsing from vast cosmic clouds, their nuclear furnaces ignite and create heavy elements in their cores. "

I'm a bit puzzled by this sentence in the description.

It has been my (newbie) understanding that "heavy elements" are created not during the ignition/burning phase of the star's "life", but only during the immense pressure of its fatal implosion.

Unless? Iron is a "heavy element"?

Relativity... Iron is heavy if dropped and lands on my toes. :ssmile:

Elements up to iron are created by normal stellar fusion processes. Elements heavier than iron are created in supernovas.

[TheZuke!]

So, the description is misleading.
Thanks.

P.s. in regard to an earlier comment by neufer.
Phillips also makes Root Beer Schnapps.
I hope to sample some, someday...

[VictorBorun]

So, the description is misleading.
Thanks.

P.s. in regard to an earlier comment by neufer.
Phillips also makes Root Beer Schnapps.
I hope to sample some, someday...

heavy, heavier and heavier still. What is a heavy element astrophysically speaking: Li to Fe, Fe to U?
Wiki paints Uranium purple meaning it's produced by kilonova neutron stars binary merges, not by SNs.
Iron is mostly gray while silicon is mostly amber meaning different types of SNs or novas.

Click to view full size image