by Ann » Sat May 28, 2022 6:24 pm
VictorBorun wrote: ↑Sat May 28, 2022 3:18 pm
I wonder
1) why did Ancient Greeks named Centaurus what Babylonians called Man Bull
2) where is the 3/4 degree bubble of RCW 86 within Centaurus and within Southern Gate [南門] [an asterism consisting of ε Centauri and α Centauri]
3) why do they say that the bubble of RCW 86 is piriform
4) how can a massive star move fast enough to get to the boundary of its fast wind bubble before it goes SuperNova
Victor, you ask many questions that I can't answer, but I think that the supernova remnant formed like this:
The RCW 86 supernova remnant in infrared.
Data: Spitzer and WISE.
I think the progenitor of RCW 86 was a fast-moving massive star with a solar-mass companion. The pair interacted with another massive star and got a gravitational kick, which sent them "running" at a high speed. During their headlong flight, the massive component exploded as a supernova, and as it did so, it ejected an expanding shell of gas. But the supernova remnant, a neutron star, kept moving in the same direction. The neutron star has now caught up with the expanding supernova shell, and now it is ionizing a small part of that shell, making it glow brightly.
We may compare the appearance of the very bright and rather small arc of RWC 86 with the appearance of the California Nebula and its ionizing runaway star, Xi Per:
But wait!! It seems I was wrong about where the progenitor star actually exploded:
V.V. Gvaramadze et.al. wrote:
We report the discovery of a solar-type star in a close, eccentric binary system with a neutron star within the young Galactic supernova remnant RCW 86. Our discovery implies that
the supernova progenitor was a moving star, which exploded near the edge of its wind bubble and lost most of its initial mass due to common-envelope evolution shortly before core collapse.
So the supernova progenitor was located at the edge of a bubble of its own creation. All hot stars eventually start blowing a strong wind, which creates a bubble around the star. But if the star moves fast enough, it can almost "outrun" its own wind bubble. The progenitor star was asymmetrically located inside its own wind bubble, near the edge of its own bubble, as it exploded.
So it didn't explode in the middle of the bubble, but near the edge of it.
As for why the progenitor star moved so fast, it was probably a runaway star. We see lots of them. Read about them
here.
As to where exactly RCW 86 is located, you can find its coordinates
here.
Ann
[quote=VictorBorun post_id=323015 time=1653751124 user_id=145500]
I wonder
1) why did Ancient Greeks named Centaurus what Babylonians called Man Bull
2) where is the 3/4 degree bubble of RCW 86 within Centaurus and within Southern Gate [南門] [an asterism consisting of ε Centauri and α Centauri]
3) why do they say that the bubble of RCW 86 is piriform
4) how can a massive star move fast enough to get to the boundary of its fast wind bubble before it goes SuperNova
[/quote]
Victor, you ask many questions that I can't answer, but I think that the supernova remnant formed like this:
[float=left][attachment=0]Supernova remnant RCW 86 fast moving progenitor Spitzer WISE.png[/attachment][c][size=85][color=#FF0000]The RCW 86 supernova remnant in infrared.
Data: Spitzer and WISE.[/color][/size][/c][/float]
[clear][/clear]
I think the progenitor of RCW 86 was a fast-moving massive star with a solar-mass companion. The pair interacted with another massive star and got a gravitational kick, which sent them "running" at a high speed. During their headlong flight, the massive component exploded as a supernova, and as it did so, it ejected an expanding shell of gas. But the supernova remnant, a neutron star, kept moving in the same direction. The neutron star has now caught up with the expanding supernova shell, and now it is ionizing a small part of that shell, making it glow brightly.
We may compare the appearance of the very bright and rather small arc of RWC 86 with the appearance of the California Nebula and its ionizing runaway star, Xi Per:
[float=left][img3="California Nebula being ionized by hot runaway star Xi Per. Image: Remidone.
"]https://upload.wikimedia.org/wikipedia/commons/thumb/d/d2/NGC_1499_%28California_Nebula%29_narrowband.jpg/792px-NGC_1499_%28California_Nebula%29_narrowband.jpg?20180824132038[/img3][/float]
[clear][/clear]
[b][size=120][color=#0040FF]But wait!![/color][/size][/b] [b][color=#FF0000]It seems I was wrong about where the progenitor star actually exploded:[/color][/b]
[quote][url=https://arxiv.org/abs/1702.00936]V.V. Gvaramadze et.al[/url]. wrote:
We report the discovery of a solar-type star in a close, eccentric binary system with a neutron star within the young Galactic supernova remnant RCW 86. Our discovery implies that [b][color=#0040FF]the supernova progenitor was a moving star, which exploded near the edge of its wind bubble[/color][/b] and lost most of its initial mass due to common-envelope evolution shortly before core collapse.[/quote]
So the supernova progenitor was located at the edge of a bubble of its own creation. All hot stars eventually start blowing a strong wind, which creates a bubble around the star. But if the star moves fast enough, it can almost "outrun" its own wind bubble. The progenitor star was asymmetrically located inside its own wind bubble, near the edge of its own bubble, as it exploded.
[b][size=110][color=#FF0000]So it didn't explode in the middle of the bubble, but near the edge of it.[/color][/size][/b]
As for why the progenitor star moved so fast, it was probably a runaway star. We see lots of them. Read about them [url=https://en.wikipedia.org/wiki/Stellar_kinematics#Runaway_stars]here[/url].
As to where exactly RCW 86 is located, you can find its coordinates [url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=RCW%2086]here.[/url]
Ann