Will The Sirius Binary System Sirius A And B Soon End Up In A Type 1a Supernova

Are there any stars within thirty light-years that might go supernova?

Planetary objects do not go supernova. I think the term you are thinking of is celestial, as only stars, rather than planets, can undergo a nova event.With this in mind, I will try to answer your question.There are only 67 bright stars within 10 parsecs (32.6 light years). Of these, there are:4 A class stars6 F class stars22 G class stars35 K class starsOne of the G class stars is Sol, our sun.Only A,B, and O class stars can go supernova. There are no B or O class stars anywhere near us. That means that there are only 4 stars within 10 parsecs of us which are able to go supernova, and all 4 would only undergo the dwarf star runaway type supernova, and so they would be unable to harm Earth deeply.The 4 A class stars areVegaSiriusFomalhautAltairFomalhaut is young, and will not nova for a very long time.Altair is only 1.2 Gigayears old, and also has a long time.Sirius is even younger with only 228 Megayears under its belt.Vega is only slightly older, at 455 Megayears.All of these are much too young to go nova any time soon. In fact, Life on Earth is older than all 3 of these stars combined!So we do have 4 stars that CAN go supernova, but 0 stars that might go nova anytime soon.We’re safe… for now!

How did researchers know that a type 1A supernova was always the same brightness?

Type 1a supernova results from a binary star system. One of them is a white dwarf star along with a (or sometimes more) companion star.Sirius B is an example of white dwarf star and you can easily spot the Sirius system on a night sky as Sirius A is the brightest star in the night sky.Image Source: Orion constellationThe white dwarf stars weigh below the Chandrasekhar Limit, which is ~1.4 times the solar mass. But in a binary system a strongly dense white dwarf can accrete matter from the companion star and eventually reach Chandrasekhar Limit and this could lead to a runaway thermonuclear reaction***.This explosion is known as Type 1a supernova. Absence of Hydrogen in the absorption spectrum is the reason it’s designated as Type 1 and presence of Silicon absorption line at [math]6150 A^{\circ}[/math] gives a.The luminous output is controlled by a nuclear chain reaction[math]^{56} Ni \rightarrow \, ^{56}Co \rightarrow \, ^{56}Fe[/math]which is same for almost every Type 1a supernova. The light curves (magnitude vs time) follow very similar patterns and it was suggested that they can be used as standard candles for measuring relative distances.Eventually Nobel Prize in Physics was given on 2011“for the discovery of the accelerating expansion of the Universe through observations of distant supernovae."So to answer your question, nearly same mass and nuclear chain reaction causes brightness of the Type 1a supernovae to be within an uncertainty of [math]8-10\%[/math] and hence they can be used as standard candles.I recommend you to read this elegant meditation by Dr. Saul Perlmutter, one of the winners of 2011 Physics Nobel Prize.For advanced readers I recommend this review articleType Ia Supernova Explosion Models*** The explosion method is still debatable and I personally know fellow colleague who’s writing dissertation on this topic).

What would happen if Sirius exploded?

Sirius is 8.5 light-years away from here. I’ll assume the way Sirius explodes is a Type I supernova as its companion dwarf star Sirius B eats its material (not going to happen in a long time by the way, so don’t worry).Scientists debate a lot on how far a supernova has to be in order to induce a mass extinction event on Earth. The estimates are from 30 to 1000 light years (this is for maximum distance, by the way). That range is big.But Sirius is 8.5 light years from us. Even the most optimistic scientists (those who say 30 light years) know that this supernova will affect us. And it does.Gamma rays from the supernova would cascade from the atmosphere. This makes a chemical reaction with the ozone, forming nitrogen oxide. Since it’s so close, the ozone layer will be depleted by a significant amount. In addition, it will form a smog that will deplete visible light from the Sun, forming an ice age.The ozone layer protects us from UV rays. Without it, havoc would ensue. It’s not just the increased sunburn risk or the increased melanoma risk. It’s that those at the bottom of the food chain (the plankton) is incredibly sensitive to UV light. They’ll be the first to die. And then a chain reaction grows which causes a collapse of the entire food chain, resulting in mass extinction.Basically, almost everything dies. Deepsea creatures and extremophiles would probably be the only ones that will definitely still survive. The rest would eventually die out over thousands of years due to the sudden ice age, the weakening of ozone, and the collapse of the food chain.