Mar 23, 2021
More than 11,000 years ago, a massive, supergiant star came to the end of its life. The star’s core collapsed to form an incredibly dense ball of neutrons, and its exterior was blasted away in an immense release of energy astronomers call a supernova.
The light from this supernova first reached Earth from the direction of the constellation Cassiopeia around 1667 A.D. If anyone alive at the time saw it, they left no records. It is likely that large amounts of dust between the dying star and Earth dimmed the brightness of the explosion to the point that it was barely, if at all, visible to the unaided eye.
The remnant of this supernova was discovered in 1947 from its powerful radio emission. Listed as Cassiopeia A, it is one of the brightest radio sources in the whole sky. More recently, the Wide-field Infrared Survey Explorer (WISE), detected infrared echoes of the flash of light rippling outwards from the supernova.
In the image, the central bright cloud of dust is the blast wave moving through interstellar space heating up dust as it goes. The blast wave travels fast – at about 6% the speed of light. By the time WISE took this image, the blast wave has expanded out to about a distance of 21 light-years from the original explosion. The flash of light from the explosion, traveling at the speed of light, has covered well over 300 light-years. The orange-colored echoes further out from the central remnant are from interstellar dust that was heated by the supernova flash centuries after the original explosion.
The false colors in this image represent different wavelengths of infrared light, which is invisible to the human eye.
Image Credit: NASA/JPL-Caltech/UCLALast Updated: Mar 23, 2021Editor: Yvette Smith
The original flash of light has covered well over 11,300 light-years.
From the article (bold mine): “The light from this supernova first reached Earth from the direction of the constellation Cassiopeia around 1667 A.D.”
I read the article and came back to check on comments (none at my writing).
I remembered that date and thought, “Oh, no. Another example of false precision.” So I was pleasantly surprised when I looked again and saw that they used “around” and not something like September 17th, 1667.
Ah, and here’s a bit more.
By the time WISE took this image, the blast wave has expanded out to about a distance of 21 light-years from the original explosion. The flash of light from the explosion, traveling at the speed of light, has covered well over 300 light-years.
I’m so used to seeing false precision from the “We’re all gonna fry!” gang that it was nice to see some less-than-exact but better-than-making-it-up numbers for a change. I’m sure their calculation wound up at an exact number, but they have the sense to know it’s not actually that number and had the good grace to say “somewhere around” their calculated number.
I have to give them a ‘Like” for that.
“The flash of light from the explosion, traveling at the speed of light, has covered well over 300 light-years.”
If this star is 11,000 light years from Earth and it has been a little more than 300 years since the explosion, the flash of light has traveled in excess of 11,300 light-years. I guess that is “well over 300 light-years”.
Yeah, got to looking at that I think it was a typo in publishing. I did a copy and paste from the article, so it looks like I got the typo; the missing “11,”
I suppose 11,000 light years more is enough “over” that you can be pretty sure the ice cream will melt before you get home.
😜
I still like the round numbers, though, as it highlights how unsettled science can be.
OK. Talk about muddled writing.
Take 1667 from 1947, that’s about 280 years. The picture of the shock wave, at 6% of the speed of light, adds about 21 years to get the “over 300.” So the recent picture (2020? 2021?) is looking at it well over 300 years later since they figured the light from the initial blast reached us in 1667.
So the 11,000 (time for light of the blast to reach us) and the over 300 (time since the blast light hit Earth) are different things, not a typo. So we missed getting a shot of the blast itself by |—| that much.
That’s as best I can figure out what they were getting at. No wonder they used round numbers. And I still like ’em,
“around 1667 A.D”
Give a ‘year or two, or a dozen’, coincides with two events extensively discussed on the WUWT, but alas nothing to do with the that supernova.
Yes you got it
a) Start of Maunder minimum (~1650)
b) Start of the CET ‘instrumental’ data records (1659)
Sorry- off topic- but:
“California looks to electric vehicles for grid stability”
https://energynews.us/2021/03/23/california-looks-to-electric-vehicles-for-grid-stability/
Believe it or not- the climate change religious fanatics in California now want to suck electricity out of your electric car during power shortages. So, not only will you not be able to charge your EV, you’ll have to sacrifice what power it has back to the grid!
All bow to the Green God.
The humor is the expectation that they’ll get more than 5 minutes of stability from EV’s. They my be mobile power sources, but without draining them dry and stranding drivers, they severely lack mega watt hours for any significant time.
That’s assuming the EV is plugged in. And if you reverse the direction of power flow, do the chargers take the DC battery power and convert it to 120V/60 cycle in sync with the grid?
Some people have thought of that apparently, see, for instance
https://www.emobilitysimplified.com/2020/01/electric-car-powers-home-v2h-charger.html
However, I’ll bet that most of the EV chargers you see around just can’t do the back to grid inversion?
Um…how far away from Earth was this event? If the event happened ~11,000 years ago and the light reached earth in ~1667, that means the star was roughly 10,600 light years away when it blew.
Why is this important? Because, we’re not seeing what it looks like right now in any spectrum. What we’re seeing is what it looked like 10,600 years ago when the infrared light we’re picking up departed the area being viewed.
Why they always refer to these types of images as if this is what it looks like “right now” is beyond me. Any number of the stars around us could have already gone supernova and we just don’t know it yet because the light won’t reach us for thousands of years.
And as a previous commenter said…the light hasn’t traveled “well over 300 light years”, it’s traveled over 300 light years since it arrived at Earth, which was, again, after it had already traveled some 10,600 light years.
Nice point. Now, think about this: According to Hubble, the Universe is expanding because galaxies are observed moving away from us and one another and the farther away they are, the faster they are moving away from us and one another.
This can be restated: Galaxies are moving away from us and one another and, the farther back in time you look, the faster they are moving away from us and one another.
In other word, as you approach the present time, galaxies are moving away from one another and us at lesser and lesser velocities. As a matter of fact, there are some 400 galaxies that are moving towards us including Andromeda which is just about (in the history of the Universe sense) to crash into the Milky Way.
These 400 galaxies are within a couple of hundred million light years of us.
Can we not hypothesize that the Universe slowed it expansion and started to contract some couple of hundred million years ago?
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These 400 galaxies are within a couple of hundred million light years of us.
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If you’re talking about galaxies in the local group, then the number is more like 80.
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Can we not hypothesize that the Universe slowed it expansion and started to contract some couple of hundred million years ago?
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No. The expansion of the Universe is due to the expansion of space and not due to the individual speeds of galaxies through space.
Jim
New paper on Black Holes
Abstract: ….. These polarimetric images carry information about the structure of the magnetic fields responsible for the synchrotron emission. Their physical interpretation is discussed in an accompanying publication.
hundreds of contributors
https://iopscience-event-horizon.s3.amazonaws.com/article/10.3847/2041-8213/abe71d/Akiyama_2021_ApJL_910_L12.pdf
Warm-up article : Mysterious swirling light gives new insights into black holes
says: “The observations suggest that the magnetic fields at the black hole’s edge are strong enough to push back on the hot gas and help it resist gravity’s pull. Only the gas that slips through the field can spiral inwards to the event horizon.”
https://www.theguardian.com/science/2021/mar/24/mysterious-swirling-light-provides-new-clue-to-black-holes
Hubble: Universe in Motionhttps://youtu.be/IN1KJ8LYW3U
https://youtu.be/NEOHFbhWiG0