Astronomers Have Discovered a Totally New Type of Violent Star Death
When a star goes supernova, it’s such a gargantuan process that it usually lasts for months. So when astronomers caught one lasting just a few weeks, they sat up and paid attention – and found a totally new type of supernova never observed before.
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That would mean that the star first dimmed then dimmed to no light.
Does humanity have the capability to video graph the whole sky southern and northern hemispheres continually?
opps, that should have been in chat.
Tau.Neutrino said:
That would mean that the star first dimmed then dimmed to no light.Does humanity have the capability to video graph the whole sky southern and northern hemispheres continually?
Not yet. There are various groups that are attempting something similar.
Desert Fireball Network in Australia comes to mind. The purpose there is to 3-D locate everything that falls out of the night sky over a large patch of Australia.
Another which comes to mind is Pan-starrs, a set of 4 telescopes (two operating and two still to go). The purpose is to map the entire sky visible from Hawaii every night.
The LSST will start operating next year and will do something similar to Pan-Starrs from South America.
There’s also mollwolfumble’s “blind spot telescope” which would see a large patch of sky that no other telescope can see.
> The supernova is called KSN 2015K, and it peaked in brightness and then faded completely in under a month, 10 times faster than other supernovae of similar brightness, which typically take months.
OK, I agree, that’s new.
There are now so many different types of supernovas that I’ve lost count. I tracked the new types through Type IIp, supernova imposters, differences in 3-D behavior, stars that die without exploding, stars that collapse early because of the formation of an iron core, the difference between merger of two white dwarfs and slow accretion onto a white dwarf from a binary red giant. I’ve tracked supernova progenitors that are asymptotic branch stars, planetary nebulae, and supergiants coloured every colour of the rainbow.
So what is it this time?
> the most likely explanation is that it was shrouded by a cocoon of gas and dust it had already ejected – only becoming visible after the dust was blasted away by the supernova’s shockwave.
That could be an asmptotic giant branch star. Such stars puff off pulses of matter at intervals. A rapid blasting away of such matter suggests that either the star shucked off matter shortly before the supernova, not too unexpected. Or we happen to be in the plane perpendicular to the stars spin axis, in which case it would be a bog standard supernova seen from an unusual direction.
> The most likely explanation, then, is what is known as an asymptotic giant branch star – a low-to-intermediate-mass red giant gaining in brightness as it dies. If KSN 2015K was on the higher mass end of this type of star, with a very slow, dusty wind blowing around it, this could have created the cocoon. However, red giant supernovae aren’t as bright as white dwarf supernovae.
They have a point. What could cause a Type II to be brighter than normal? Orientation? Or what could cause a Type Ia to be shrouded in nearby material? Orientation of accretion disk from red giant companion? Or what could cause a faster explosion from two white dwarfs colliding?
Something of a mystery.
Tau.Neutrino said:
That would mean that the star first dimmed then dimmed to no light.Does humanity have the capability to video graph the whole sky southern and northern hemispheres continually?
Oops, I gave you the wrong answer to that. The answer is “yes”. Well, almost. It can’t see within 60 degrees of the Sun and may have other blind spots.
“The All Sky Automated Survey for SuperNovae or ASAS-SN is an automated program to search for new supernovae and other astronomical transients. It has robotic telescopes in both the northern and southern hemispheres. Currently, it can survey the entire sky approximately once every day.”
“Initially, there were four ASAS-SN telescopes at Haleakala and another four at Cerro Tololo, an LCOGT site. Twelve more telescopes were deployed in 2017 in Chile, South Africa and Texas,”
More details in https://en.m.wikipedia.org/wiki/All_Sky_Automated_Survey_for_SuperNovae