If a nearby star goes supernova?

[weeman]

Lets say for a second that Betelguese suddenly became a supernova. How bright would it shine in the night sky? In the March 2007 edition of National Geographic, there is an article about supernovae. At the beginning it has an interesting quote:<br /><br />"Once a second, somewhere in the Universe, a star shines with the brilliance of an entire galaxy."<br /><br />I've never been completely knowledgable with supernovae. They are some of the most intriguing objects that I have seen in Astronomy, and want to learn more. So, again my question is:<br /><br />If a star in our nearby region of the Milky Way were to go supernova, how bright would it shine in the night sky? <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>

 

[qso1]

It depends on how supernova it goes and nobody really knows for sure since we haven't had one close by so to speak, go off in quite awhile.<br /><br />Because astronomers have long been saying Betelgeuse may be close, I have it going partial supernova in my illustrated book series dealing with human spaceflight. The year is 2016. But at some 400 Ly out, it only gets to be somewhat brighter than Sirius. The partial event is another reason it doesn't brighten to something like another sun in the sky.<br /><br />If Sirius were to go supernove, at only 8.9 Ly distant, we'd be in deep you know what. Same if a star like Eta Carinae finally exploded. Eta Car is 7 or 8,000 Ly out and appears to be in the beginning stages of going supernova.<br /><br />And that brings us to nobody really knows. Its always been assumed that a star will go supernova, big bang...done. But Eta Carinae shows the process could actually come in several stages over hundreds of years before finally blowing for good.<br /><br />Eta Car would probably be the most spectacular supernova in our Galaxy. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[docm]

Eta Carina might have already gone and it just hasn't reached us yet.<br /><br />If we survive the radiation pulse the the sky will get real pretty as the nebula expands, but shame on us if the resulting pulsar's poles rotate our way <img src="/images/icons/tongue.gif" /> <div class="Discussion_UserSignature"> </div>

 

[qso1]

Thats correct, it would have blown some 8,000 years ago. That would also be one spectacular sight and like you said, we would have to survive the blast of radiation that would accompany the light show. All assuming we have a pretty good understanding of how these things work in actual situations. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[weeman]

I was thinking that if it were to be a very powerful supernova, if it would mean the end of night time <img src="/images/icons/tongue.gif" /><br /><br />Although, it seems to me that it would be quite a dazzling spectacle! Of course, then we might have many problems to deal with. <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>

 

[ianke]

Could Eta Carina Kill us? In other words would the radiation from 8000ly distance be that powerful?<br /><br />I realize Eta Carina is a really massive star, but I thought we were far enough away to be relatively safe. <div class="Discussion_UserSignature"> </div>

 

[3488]

Seeing as radiation from Eta Carinae would propagate outwards (remember the square law). Double the distance from the source, energy received is 25%. <br /><br />I am not sure if Eta Carinae would be dangerous. Betelgeuse being much closer could well be. Rigel, Alnitak, Alnilam, Deneb, Rho Cassiopea, Eta Aurigae, etc are all likely to go supernova.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[qso1]

Good point and it may well be that Eta Car might not actually prove as dangerous should it blow. Betelgeuse would probably be more of a hazard to anyone who might be in space if it were to blow but may not be a danger to anyone on earth due to the ozone layer protection. Guess theres just enough uncertainty not to really know. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[alokmohan]

We are too far away.

 

[nexium]

The atmosphere of Earth is thought to protect us from the intense radiation of a super Nova, so there would be perhaps a one percent increase in cancer deaths, if Sirus went super nova. Pesons in space would die without shielding. Betelgeuse has lots more mass, and thus potential for lots more dangerous radiation but 2500 times more radiation is needed than from Sirus which is 50 times closer. My guess is negligible hazard to Earth when Eta Carnae goes super nova because of the 4000 light years. There is some evidence that planets continue orbit a billion miles from a super nova, but they are likely stripped of most of their volatiles.<br />We are all but certain that Sirus has too little mass to go supernova. Neil

 

[docm]

A supernova could result in a big enough gamma ray pulse to induce the conversion of nitrogen to nitrogen dioxide in the upper atmosphere, depleting the ozone layer 50% or more, perhaps entirely, in just a few minutes. <br /><br />Goodbye ozone layer, hello high intensity ultraviolet. Phytoplankton and surface dwellers die and some researchers think global cooling follows, making life hard for what remains.<br /><br />Just such an event is a possible cause of the Ordovician extinction 450 m/y ago, in which 60% plus of Earths lifeforms died. <br /><br />This could result from a supernova <100 l/y distant or from a gamma ray burst aimed our way from up to several thousand l/y away. <div class="Discussion_UserSignature"> </div>

 

[SpeedFreek]

I wish I could remember where I read that we are really only in danger from stars within a radius of around 30 light years, in terms of deadly radiation. It may have been on BAUT. <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[ianke]

Thanks to all on this. I was under a similar understanding, but some of the earlier posts had me wondering if I had it wrong. <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

Ideas here flow like "buttah" <img src="/images/icons/laugh.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[search]

LINK<br />"Scientists at NASA and Kansas University have determined that the supernova would need to be within 26 light years from Earth to significantly damage the ozone layer and allow cancer-causing ultraviolet radiation to saturate the Earth's surface.<br />An encounter with a supernova that close only happens at a rate of about once in 670 million years(...)<br />The new calculations are based largely on advances in atmospheric modeling, analysis of gamma rays produced by a supernova in 1987 called SN1987a, and a better understanding of galactic supernova locations and rates. A supernova is an explosion of a star at least twice as massive as our Sun."

 

[docm]

Newer data, good. <br /><br />That however does not help if we're in the path of a GRB's polar emission. We'd be fried at a lot more than 26ly. <div class="Discussion_UserSignature"> </div>

 

[weeman]

Thanks for all the info. I wasn't really thinking about radiation at all when I posted this thread, I guess that could be a bigger problem than too much light from a supernova! <br /><br />It's amazing that a single supernova can emit radiation for several lightyears. Of course, it is far just to human standards, because in space, it isn't necessarily far at all <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>

 

[qso1]

speedfreek:<br />I wish I could remember where I read that we are really only in danger from stars within a radius of around 30 light years,<br /><br />Me:<br />When I did the section in my book where Betelgeuse goes partial supernova...I looked at several astronomy sites and a couple of books to try to get a definitive answer and I recall seeing that Betelgeuse would probably be a danger to astronauts but not those on the ground. I also recall running across a site that mentioned something along the lines of what your saying...stars within 30 Ly which IIRC, would be a danger to astronauts and the rest of us.<br /><br />There was some uncertainty due in part to the probability that if such an event takes place. It will probably do a little of everything. Eta Car for example. I tend to agree that if it goes supernova it probably won't affect us that much but in some circles, it is theorized that Eta Car may eventually go hypernova. Becoming like one of those extremely bright super/hypernova objects that can be seen in galaxies tens of millions of Ly away. Wish I could think of a recent example. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[qso1]

SEARCH:<br />"Scientists at NASA and Kansas University have determined that the supernova would need to be within 26 light years from Earth...<br /><br />Me:<br />Ah...that answers the question a bit better. 26 light years. AFAIK, there are no candidate supernova stars that close to us. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[lukman]

LINK <br />Impact on Earth<br /><br />A near-Earth supernova is an explosion resulting from the death of a star that occurs close enough to the Earth (roughly fewer than 100 light-years away) to have noticeable effects on its biosphere. Gamma rays are responsible for most of the adverse effects a supernova can have on a living terrestrial planet. In Earth's case, gamma rays induce a chemical reaction in the upper atmosphere, converting molecular nitrogen into nitrogen oxides, depleting the ozone layer enough to expose the surface to harmful solar and cosmic radiation. The gamma ray burst from a nearby supernova explosion has been proposed as the cause of the end Ordovician extinction, which resulted in the death of nearly 60% of the oceanic life on Earth. [74]<br /><br />Speculation as to the effects of a nearby supernova on Earth often focuses on large stars, such as Betelgeuse, a red supergiant 427 light-years from Earth which is a Type II supernova candidate. Several prominent stars within a few light centuries from the Sun are candidates for becoming supernovae in as little as a millennium.[75] Though spectacular, these "predictable" supernovae are thought to have little potential to affect Earth. Type Ia supernovae, though, are thought to be potentially the most dangerous if they occur close enough to the Earth. Because Type Ia supernovae arise from dim, common white dwarf stars, it is likely that a supernova that could affect the Earth will occur unpredictably and take place in a star system that is not well studied. One theory suggests that a Type Ia supernova would have to be closer than a thousand parsecs (3300 light years) to affect the Earth.[76]<br /><br />Recent estimates predict that a Type II supernova would have to be closer than eight parsecs (twenty-six light years) to destroy half of the Earth's ozone layer.[77] Such estimates are mostly concerned with atmospheric modeling and considered <div class="Discussion_UserSignature"> </div>

 

[bdewoody]

This is the most interesting question I've seen asked in here in a long time and possibly the most relevant. I can hardly imagine what the night sky would look like if a nearby (but not too nearby) star went nova or supernova. <div class="Discussion_UserSignature"> <em><font size="2">Bob DeWoody</font></em> </div>

 

[search]

LINK Supernova 1987A

 

[search]

LINK Supernova 1987A

 

[chyten]

<b>That however does not help if we're in the path of a GRB's polar emission. We'd be fried at a lot more than 26ly. </b><br /><br />Qualitatively, "at about 10 times more than 26 ly" since someone in the path of a GRB receives about 100 times the energy of "mere" supernova. <br /><br />Which means Betelgeuse would be dangerous, although not "extinction-level dangerous", if we had the incredible bad luck to get in its GRB beam. Eta Carina is too far away to harm us.