Astronomers make first radio observations of key type of supernova
The uncertainty of science: Using a variety of telescopes, astronomers have not only made the first radio observations of key type of supernova, they have also detected helium in the data, suggesting that this particular supernova of that type was still atypical.
This marks the first confirmed Type Ia supernova triggered by a white dwarf star that pulled material from a companion star with an outer layer consisting primarily of helium; normally, in the rare cases where the material stripped from the outer layers of the donor star could be detected in spectra, this was mostly hydrogen.
Type Ia supernovae are important for astronomers since they are used to measure the expansion of the universe. However, the origin of these explosions has remained an open question. While it is established that the explosion is caused by a compact white dwarf star that somehow accretes too much matter from a companion star, the exact process and the nature of the progenitor is not known. [emphasis mine]
The highlighted sentences are really the most important take-away from this research. Type Ia supernovae were the phenomenon used by cosmologists to detect the unexpected acceleration of the universe’s expansion billions of years ago. That research assumed these supernovae were well understood and consistently produced the same amount of energy and light, no matter how far away they were or the specific conditions which caused them.
This new supernovae research illustrates how absurd that assumption was. Type Ia supernovae are produced by the interaction of two stars, both of which could have innumerable unique features. It is therefore unreasonable as a scientist to assume all such supernovae are going to be identical in their output. And yet, that is what the cosmologists did in declaring the discovery of dark energy in the late 1990s.
It is also what the scientists who performed this research do. To quote one of the co-authors: “While normal Type Ia supernovae appear to always explode with the same brightness, this supernova tells us that there are many different pathways to a white dwarf star explosion.”
Forgive me if I remain very skeptical.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
The uncertainty of science: Using a variety of telescopes, astronomers have not only made the first radio observations of key type of supernova, they have also detected helium in the data, suggesting that this particular supernova of that type was still atypical.
This marks the first confirmed Type Ia supernova triggered by a white dwarf star that pulled material from a companion star with an outer layer consisting primarily of helium; normally, in the rare cases where the material stripped from the outer layers of the donor star could be detected in spectra, this was mostly hydrogen.
Type Ia supernovae are important for astronomers since they are used to measure the expansion of the universe. However, the origin of these explosions has remained an open question. While it is established that the explosion is caused by a compact white dwarf star that somehow accretes too much matter from a companion star, the exact process and the nature of the progenitor is not known. [emphasis mine]
The highlighted sentences are really the most important take-away from this research. Type Ia supernovae were the phenomenon used by cosmologists to detect the unexpected acceleration of the universe’s expansion billions of years ago. That research assumed these supernovae were well understood and consistently produced the same amount of energy and light, no matter how far away they were or the specific conditions which caused them.
This new supernovae research illustrates how absurd that assumption was. Type Ia supernovae are produced by the interaction of two stars, both of which could have innumerable unique features. It is therefore unreasonable as a scientist to assume all such supernovae are going to be identical in their output. And yet, that is what the cosmologists did in declaring the discovery of dark energy in the late 1990s.
It is also what the scientists who performed this research do. To quote one of the co-authors: “While normal Type Ia supernovae appear to always explode with the same brightness, this supernova tells us that there are many different pathways to a white dwarf star explosion.”
Forgive me if I remain very skeptical.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Tangential to topic of radio-astronomy, here’s a proposal to get Arecibo rebuilt into a smaller, cheaper, and better state. Next Generation Arecibo Telescope. NGAT-130:
http://dispatchesfromturtleisland.blogspot.com/2023/05/arecibo-20.html
Nothing is exactly identical or always the same in nature.
Why would stars of any type be different?
How many Starlink-type steerable antennae would it take to build out the basic infrastructure of Arecibo 2.0?
Yes, these apertures are tinier than even the 2.0 proposal, but synthetic aperture software can do wonders, and software has great growth potential. Don’t let perfection be the enemy of the good, and the doable!
The reasons that all type 1A supernova are considered to be the same are quantum mechanical. At the intense gravitational field strength of a white dwarf star approaching the Chandrasekhar limit all matter is in a degenerate state with the electrons forced into the closest possible orbits outside the nucleus. When the limit is reached the electrons are forced into the nucleus turning everything in the atom into neutrons. This collection of neutrons collapses into a solid neutron star and releases the same amount of gravitational collapse energy regardless of what the previous matter make up of the 2 stars involved were.