Supernovas

[vintersorg]

Hi everyone, I'm new to this forum, and I've had something going through my mind.<br /><br />Now, there are some things I'm about to write I'm not totally sure, since I've read them in a while and I'm not sure where or how accurate it was.<br /><br />Thing is, Eta Carinae could explode any moment from now, some claim, and, if it were to explode it would create a massive light visible from Earth, even at day. My question is: how long would this "light" be visible? Would it be a few seconds and I could simply lose it because I was home or sleeping, or it would take longer? How much? I know it may not even explode in the next few millenia, but well, I'm quite curious about it.<br /><br />Also, I've read that the last supernova that exploded in our galaxy was about 200-400 years ago? I find that hard to believe, but since I don't know, I must ask. Is this true? When has the last supernova, visible from Earth exploded? If so, there are any historical writings from the people at the time about this event?<br /><br />Thank you in advance, sorry for the burst of questions, some of them may even sound a little silly.

 

[docm]

How long would the brightest part of am Eta Carinae supernova last? Weeks at least & probably with a king-sized remnant, but there is also a fairly high likelihood it will be a hypernova instead. <br /><br />A hypernova would be 100+ times as powerful and likely create gamma ray bursts from its poles. If that's the case hope the poles aren't aimed at us, which it looks like they won't be.<br /><br />In either case it'll be one helluva show.<br /><br />AFAIK SN 1680/1667 (Cassiopeia A, 3C 461) was the last in the Milky Way. This is a bit odd in that galaxies like the Milky Way often see one every 50 years or so.<br /><br />Supernova candidates besides Eta Carinae include Rho Cassiopeiae, IK Pegasi, RS Ophiuchi, KPD1930+2752, HD 179821, IRC+10420, VY Canis Majoris, Gamma Velorum, WR 104, Betelgeuse, Antares and Spica. IK Pegasi is the closest @ 150 light years. <div class="Discussion_UserSignature"> </div>

 

[derekmcd]

Eta C's poles are not directed at us. I could be wrong, but I remember seeing pics that showed expulsion of its gasses that would lead us to believe that Eta C's axis in not pointed at us.<br /><br />We should be relieved. A GRB from this star being so close could catastrophic.<br /><br />Eta Car may have gone supernova already... we just dont know it yet. The light has not reached us. Should this happen, yes... It would likely be visible during the day and last several months if not longer. It might even be bright enough to read a book during the night.<br /><br />This would not be a minor event. Every major network news channel would all over this. <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[vintersorg]

Thank you both for the reply. I was wondering if I could lose such a show if it were to happen, apparently that's not the problem at all. It has to happen first (or reach Earth if it has already.).<br /><br />I had no idea supernovas could happen that often in our galaxy, are there no historical accounts of the people that were able to see the last supernovas? Or rarely other stars would provide such a show like Eta Carinae might?

 

[MeteorWayne]

Supernovas have been observed in our galaxy by eye in the daytime from earth.<br /><br />"The supernova was noted on July 4, 1054 A.D. by Chinese astronomers as a new or "guest star," and was about four times brighter than Venus, or about mag -6. According to the records, it was visible in daylight for 23 days, and 653 days to the naked eye in the night sky. It was probably also recorded by Anasazi Indian artists (in present-day Arizona and New Mexico), as findings in Navaho Canyon and White Mesa (both Arizona) as well as in the Chaco Canyon National Park (New Mexico) indicate; there's a review of the research on the Chaco Canyon Anasazi art online. In addition, Ralph R. Robbins of the University of Texas has found Mimbres Indian art from New Mexico, possibly depicting the supernova. ?<br /><br />This left us the Crab Nebula, which can still be seen today.<br /><br /> <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>

 

[Saiph]

the event would be visible to the naked eye on a timescale of weeks (maybe a month or two). <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>