Gamma-ray burst could kill off ocean life
in [Physics]
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From: Sam Wormley on 25 Jul 2010 17:13 On 7/25/10 3:59 PM, Brad Guth wrote: > On Jul 25, 11:58 am, palsing<pnals...(a)gmail.com> wrote: >> On Jul 25, 6:05 am, Sam Wormley<sworml...(a)gmail.com> wrote: >> >>> On 7/24/10 11:04 PM, Brad Guth wrote: >> >>>> How much gamma did we get from Sirius(B)? >> >>> You do know that Sirius B is a white dwarf and not a black >>> hole, Right? >> >> And, just to be clear, this means that Sirius B was never a >> supernova... >> >> \Paul A > > The original mass of Sirius(B) was likely less than 10 Ms, and as a > result it didn't live very long before going postal. > > ~ BG The fact that Sirius B is observed to be a white dwarf means that it was less than eight solar masses as a main sequence star. Ref: http://stars.astro.illinois.edu/sow/sirius.html "Sirius B is the chief member of a trio of classic white dwarfs, the others Procyon B and 40 Eridani B. Its high mass and tiny radius lead to an amazing average density of 1.7 metric tons per cubic centimeter, roughly a sugar cube. White dwarfs are the end products of ordinary stars like the Sun, tiny remnants that were once nuclear-fusing cores that have run out of fuel. Most are balls of carbon and oxygen whose fates are merely to cool forever. To have evolved first, Sirius B must once have been more massive and luminous than Sirius A. That its mass is now lower is proof that stars lose considerable mass as they die. Given the mass of the white dwarf and the 250 million year age of the system, Sirius B may once have been a hot class B3-B5 star that could have contained as much as 5 to 7 solar masses, the star perhaps losing over 80 percent of itself back into interstellar space through earlier winds".
From: Sam Wormley on 25 Jul 2010 17:22 On 7/25/10 3:56 PM, Brad Guth wrote: > On Jul 25, 6:05 am, Sam Wormley<sworml...(a)gmail.com> wrote: >> On 7/24/10 11:04 PM, Brad Guth wrote: >> >>> How much gamma did we get from Sirius(B)? >> >> You do know that Sirius B is a white dwarf and not a black >> hole, Right? > > It was nearby when its helium flashover took place. > > Are you suggesting that a powerful nova is not gamma worthy? > > ~ BG There is no evidence that Sirius B has ever gone Nova--For one thing Sirius A and B are too far apart. Background on Helium Flash for Brad http://en.wikipedia.org/wiki/Helium_flash "Stars with greater than about 2.25 solar masses start to burn helium without their core becoming degenerate and so do not exhibit this type of helium flash". "The helium flash is NOT directly observable on the surface by electromagnetic radiation. The flash occurs in the core deep inside the star, and the net effect will be that all released energy is absorbed by the entire core leaving the degenerate state to become nondegenerate. Earlier computations indicated that a nondisruptive mass loss would be possible in some cases, but later star modeling taking neutrino energy loss in account indicates no such mass loss".
From: Brad Guth on 25 Jul 2010 19:03 On Jul 25, 2:22 pm, Sam Wormley <sworml...(a)gmail.com> wrote: > On 7/25/10 3:56 PM, Brad Guth wrote: > > > On Jul 25, 6:05 am, Sam Wormley<sworml...(a)gmail.com> wrote: > >> On 7/24/10 11:04 PM, Brad Guth wrote: > > >>> How much gamma did we get from Sirius(B)? > > >> You do know that Sirius B is a white dwarf and not a black > >> hole, Right? > > > It was nearby when its helium flashover took place. > > > Are you suggesting that a powerful nova is not gamma worthy? > > > ~ BG > > There is no evidence that Sirius B has ever gone Nova--For one thing > Sirius A and B are too far apart. > > Background on Helium Flash for Brad > http://en.wikipedia.org/wiki/Helium_flash > > "Stars with greater than about 2.25 solar masses start to burn helium > without their core becoming degenerate and so do not exhibit this type > of helium flash". > > "The helium flash is NOT directly observable on the surface by > electromagnetic radiation. The flash occurs in the core deep inside the > star, and the net effect will be that all released energy is absorbed by > the entire core leaving the degenerate state to become nondegenerate. > Earlier computations indicated that a nondisruptive mass loss would be > possible in some cases, but later star modeling taking neutrino energy > loss in account indicates no such mass loss". Your purely subjective interpretation is noted. Sirius(B) started off as a 9 Ms. Go fish. Sirius(B) may also have consumed Sirius(C). Go fish again. You don't even know how close we were to those Sirius stars. ~ BG
From: Brad Guth on 25 Jul 2010 19:06 On Jul 25, 2:13 pm, Sam Wormley <sworml...(a)gmail.com> wrote: > On 7/25/10 3:59 PM, Brad Guth wrote: > > > > > On Jul 25, 11:58 am, palsing<pnals...(a)gmail.com> wrote: > >> On Jul 25, 6:05 am, Sam Wormley<sworml...(a)gmail.com> wrote: > > >>> On 7/24/10 11:04 PM, Brad Guth wrote: > > >>>> How much gamma did we get from Sirius(B)? > > >>> You do know that Sirius B is a white dwarf and not a black > >>> hole, Right? > > >> And, just to be clear, this means that Sirius B was never a > >> supernova... > > >> \Paul A > > > The original mass of Sirius(B) was likely less than 10 Ms, and as a > > result it didn't live very long before going postal. > > > ~ BG > > The fact that Sirius B is observed to be a white dwarf means > that it was less than eight solar masses as a main sequence star. > > Ref:http://stars.astro.illinois.edu/sow/sirius.html > > "Sirius B is the chief member of a trio of classic white dwarfs, the > others Procyon B and 40 Eridani B. Its high mass and tiny radius lead to > an amazing average density of 1.7 metric tons per cubic centimeter, > roughly a sugar cube. White dwarfs are the end products of ordinary > stars like the Sun, tiny remnants that were once nuclear-fusing cores > that have run out of fuel. Most are balls of carbon and oxygen whose > fates are merely to cool forever. To have evolved first, Sirius B must > once have been more massive and luminous than Sirius A. That its mass is > now lower is proof that stars lose considerable mass as they die. Given > the mass of the white dwarf and the 250 million year age of the system, > Sirius B may once have been a hot class B3-B5 star that could have > contained as much as 5 to 7 solar masses, the star perhaps losing over > 80 percent of itself back into interstellar space through earlier winds". Again, your purely subjective interpretation or acceptance of the mainstream status quo is noted. Now like good parrot you should get back in your cage and on your perch. ~ BG
From: Sam Wormley on 25 Jul 2010 19:41
On 7/25/10 6:06 PM, Brad Guth wrote: > On Jul 25, 2:13 pm, Sam Wormley<sworml...(a)gmail.com> wrote: >> On 7/25/10 3:59 PM, Brad Guth wrote: >> >> >> >>> On Jul 25, 11:58 am, palsing<pnals...(a)gmail.com> wrote: >>>> On Jul 25, 6:05 am, Sam Wormley<sworml...(a)gmail.com> wrote: >> >>>>> On 7/24/10 11:04 PM, Brad Guth wrote: >> >>>>>> How much gamma did we get from Sirius(B)? >> >>>>> You do know that Sirius B is a white dwarf and not a black >>>>> hole, Right? >> >>>> And, just to be clear, this means that Sirius B was never a >>>> supernova... >> >>>> \Paul A >> >>> The original mass of Sirius(B) was likely less than 10 Ms, and as a >>> result it didn't live very long before going postal. >> >>> ~ BG >> >> The fact that Sirius B is observed to be a white dwarf means >> that it was less than eight solar masses as a main sequence star. >> >> Ref:http://stars.astro.illinois.edu/sow/sirius.html >> >> "Sirius B is the chief member of a trio of classic white dwarfs, the >> others Procyon B and 40 Eridani B. Its high mass and tiny radius lead to >> an amazing average density of 1.7 metric tons per cubic centimeter, >> roughly a sugar cube. White dwarfs are the end products of ordinary >> stars like the Sun, tiny remnants that were once nuclear-fusing cores >> that have run out of fuel. Most are balls of carbon and oxygen whose >> fates are merely to cool forever. To have evolved first, Sirius B must >> once have been more massive and luminous than Sirius A. That its mass is >> now lower is proof that stars lose considerable mass as they die. Given >> the mass of the white dwarf and the 250 million year age of the system, >> Sirius B may once have been a hot class B3-B5 star that could have >> contained as much as 5 to 7 solar masses, the star perhaps losing over >> 80 percent of itself back into interstellar space through earlier winds". > > Again, your purely subjective interpretation or acceptance of the > mainstream status quo is noted. Now like good parrot you should get > back in your cage and on your perch. > > ~ BG Awk--What evidence do you have? None! |