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Space Science

Exploding Star May Be Seen From Earth 35

Posted by michael from the kaboom dept.
fjordboy writes "The star Rho Cas, which can be seen by the naked eye from the Northern Hemisphere, is showing signs that it may be exploding in the near future. Rho exploded in 2000, creating a cloud of gas over 10,000 times the size of earth (which isn't all that large in space scales), however, the same star is showing signs of collapsing which may point to a much larger explosion in the near future, which should be large enough to be seen by backyard astronomers with little to no specialized equipment. MSNBC has more info, Space.com also has the story here and here."
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Exploding Star May Be Seen From Earth More

Exploding Star May Be Seen From Earth

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  • Wow (Score:3, Funny)

    by GigsVT ( 208848 ) on Thursday January 09, 2003 @01:17PM (#5048635) Journal
    That star must be pretty damn close if it exploded in 2000 and we can already see it.
    • It didn't explode in 2000, the explosion was first recorded in 2000. The star is over 10,000 light-years away.

      • Re:Wow (Score:2, Informative)

        by Cy Guy ( 56083 )
        Yes the write-up needs lots of work.

        The title being not news, people can see about a dozen novae & supernovae from the Earth every year, the interesting fact is that you might be able to see it with the naked eye.

        But the biggest problem is that what we would see would not be an explosion but an implosion of matter which will release huge quantities of light and other radiation.

        • Yeah..you're right. I should have proof-read it or at least compared it to the space.com article. *shrug* I just thought it was interesting and thought the slashdot crowd would too. If I had mentioned the 50k years or the 10000 light years, it probably wouldn't have been posted. *grin* Hind-sight is 20/20 I guess.

      • Skymap Pro [skymap.com]'s telling me that it's 11649 +/- 7856 light years away, so the 10,000 figure isn't necessarily very accurate. I'm not sure which catalogue it's pulling it from.

  • 10,000 light years away and I'm not holding my breath waiting for the big pop, which the article indicates could come in the next 50,000 years.

    But I would assign an undergrad to keep an eye on this daily and be prepared with some high powered [space based] telescopes to capture it's death in all it's glory.

    Almost like being there?

    What would the cost be to take a picture of this star every day/month and just observe it?
    • oriiginal story: it may be exploding in the near future

      Hmm, interesting phrasing considering the star exploded (if it did explode) a long, long, long time ago. (10,000+ years). Even if the Sun were to explode we wouldn't know for several minutes, strange to think.
      • We should get plenty of warning of when the explosion would happen BEFORE it happens.....but once it did, yeah, like 8 minutes before we toast. A drastic change in neutrino emissions (which do get to us at lightspeed from the core) should tip us off, we hope

        Events in the core of the Sun would take a long time, a million years, [solarviews.com] to work their way through the many layers of the Sun to the surface.

        • Yes, that's why I said if the Sun were to explode. :)

          The model I remember is that the sun will turn into a red giant in a mere several billion years, enveloping the Earth, then contract again. It may never explode because it is too small. [cornell.edu]

          I don't spend a lot of time worrying about the Sun exploding. Having a big meteor hit us is a lot more probable. Well, anything is more probable than an event that is probably impossible.... Far more probable that the errant asteroid is that will all get caught up in a nuclear war, our own little bitty version of a supernova. What are the chances of humans lasting another billion years? Hmm. Probably depends on us.
          • I do remember a novel based on the premise that a giant asteroid/planetoid thing was on a collision course with the Sun, coming into a pole on a trajectory that made it impossible to spot until too late (like 300 years notice or some such in the book)....wouldn't hurt the core, but the disruption to the photosphere would trash the earth for a few thousand years before going back to normal.......that would be a major bummer!
  • Whew. I wont be needing my crash helmet and lead lined jockstrap.
  • Lobel said because of the star's advanced age, it could go supernova in as little as 50,000 years.

    So much for being alive when it makes the final boom. Interestingly enough they said that the star had a prior recorded "shedding" of material in the 1940's, which begs the question "Is this normal?" Since it seems like it's getting ready to do it again after 2 such prior expulsions, perhaps this is actually the process of an explosing massive star? Multiple explosions, each more furious then the last until finally it destroys itself...

    <Cartman voice>Kick ass</Cartman voice>
    • Interestingly enough they said that the star had a prior recorded "shedding" of material in the 1940's, which begs the question "Is this normal?"
      Apparently, yes. There are lots of "planetary nebulae" out there, which are composed of the outer layers lost by aging, dying stars. From what little I understand (IANAastronomer) a great deal of the carbon in the universe is shed by stars which are too small to go supernova, but which nonetheless manage to get it from their cores to their outer layers and then blow it off into space. Some of those things are practically exhaling Buckyballs.

      Even supernovae are not exempt. The star Sanduleak whatever, which appears to have been the source of SN 1987A, was a blue star; apparently it had shed its red-giant outer layers as a nebula and had stripped down to little more than its core before it blew.

  • So which is it? (Score:3, Funny)

    by matth ( 22742 ) on Thursday January 09, 2003 @02:20PM (#5049095) Homepage
    Rho Cas, as it is often referred to, is visible to skywatchers in the Northern Hemisphere who have dark sky conditions away from city lights, prompting the astronomers to suggest that amateurs might spot the next explosion.

    But then they go on to say:
    An eruption would pose no danger to Earth, and in fact would likely be spotted only by seasoned skywatchers who know how to navigate the sea of stars surrounding the relatively dim Rho Cas.
    • I think the text is ambiguous enough to allow either interpretation. MSNBC (and space.com) have "might spot" and "likely be spotted," which are both pretty conditional and relative phrases. I think either interpretation holds true simply because there is so much gray area and they (purposely) keep it ambiguous. *shrug*
    • There are seasoned skywatchers out there who know how to navigate the sea of stars, and they are amateurs! Amazing, no?

    • Re:So which is it? (Score:5, Insightful)

      by jesterzog ( 189797 ) on Thursday January 09, 2003 @04:25PM (#5050216) Journal

      Most of the experienced skywatchers in the world are amateurs. Professional astronomy hardly ever involves directly looking at the sky. The amateurs are the people who go out on their own initiative and look at the sky, get to know small regions containing thousands of stars (or more), and can often immediately spot any change and report it. Back yard astronomers frequently provide historical observation data that professionals refer to later on when it's relevant to whatever they're studying.

      Supernova 1987A was first discovered [aavso.org] by several such people who've spent most of their lives learning where the stars should be, and could immediately tell that something was different.

    • Re:So which is it? (Score:3, Interesting)

      by msheppard ( 150231 )
      The stars of a constillation are assigned greek letters in order of their brightness (roughly). So the brightest star in a constillation is alpha. Rho (a little p) is the 17th letter in the greek alphabet so 'rho cas' will be the 17th brightest star in the constalltion cassiopia. Go outside some night, find the big W and see how many of its stars you can see. If you can see more than 17 you can see 'rho cas.'

      Rho Cas is magnitude 4.51. The lower the number the brighter the star. Magnitude 1 is a very easily seen star. 2 is pretty easy to see from most locations. Magnitude 3, you're gonna need to be away from a city. Mag 4 you need to be in the country really. Mag 5 you better have binocs or a scope.

      BTW: The space station is often mag -1, and can be found with ease using the tools at www.heavens-above.com .

      PPS: My advice on getting into astronomy, get some software (skymap.com / starrynight) THEN get some good binocs (tons of astronomy buying guides online) THEN maybe get a scope or ten.

      (Then convert your webcam to work on your star-drive scope and hook it to an 802.11b laptop and do some star gazing from your living room)

      M@

  • Nova, this is a Nova (Score:5, Interesting)

    by pease1 ( 134187 ) <bbunge@l a d y a n d t r a m p.com> on Thursday January 09, 2003 @03:02PM (#5049378)
    Traditionally, events of this sort are called nova by astronomers.

    Nova events that are visible to the naked eye don't happen every day, but aren't all that uncommon. In my 20 years of being an active amateur astronomer, I've seen a half dozen or so. Most are very dim and require the use of some sort of chart to tell the nova from nearby stars.

    When they are this dim, it is a requirement to get out under dark skys and away from the CRT or LCD.

    Nova events that don't get as bright as six or seventh magnitude require some sort of optical aid - perhaps just binoculars - to see. These sorts of events happen all the time.

    At mag 4.5 this is a pretty bright star (greek letter named stars usually are pretty bright since they were cataloged hundreds of years ago before the invention of the telescope).

    Thus, this one might get bright enough to actually be pretty easy to see. Only time will tell.

    After all, as far as we know, some other star has gone supernova and the light will only reach Earth today in the form of an daylight object, or something that is as bright as Venus or even the Moon.

    • The plural of "nova" is "novae", pronounced "noh-vee".

      (Fscking Slashdot response timer!)

    • Are you sure about this? Traditionally, a "nova" occurs when accreting material builds up enough on a white dwarf to retrigger fusion burning, resulting in a rather large "Boom!" as all of the fresh yummy hydrogen goes away relatively rapidly. This isn't really the same thing - the triple-alpha process is becoming unstable inside the star, occasionally shoving large quantities of gas off the star when a large supply of helium reaches the core. It's a "dying planetary nebula", basically.

      "Novae" were named because they were "new stars" that showed up out of nowhere (because the white dwarf was originally nowhere near visible) and then disappeared. Rho Cas isn't like that - it's bright enough to be seen normally, but is changing its brightness rapidly.

      It definitely looks like it's going to go supernova, though. I don't know its actual mass, so I'm not sure whether or not it's an "absolute given" or not.

  • From the article:

    "Rho Cas is faraway compared to most stars visible at night, more than 10,000 light-years. It is visible because it is among the most massive stars known, 20 to 40 times more heavy than the Sun, and shines nearly a million times more brightly than the Sun. If it replaced our Sun, its girth would consume Earth and Mars."

    And from NASA [nasa.gov]:

    "Black holes are the evolutionary endpoints of stars at least 10 to 15 times as massive as the Sun."

    So, is this a black hole waiting to happen? I would think that would be a thing of note, yet I don't see it mentioned in the article. They talk about it going supernova, then collapsing, but they don't say into what... Anyone know?

    -T

    • "...20 to 40 times more heavy than the Sun..."


      "Black holes are the evolutionary endpoints of stars at least 10 to 15 times as massive as the Sun."

      is this a black hole waiting to happen?
      Some stars throw off enough matter not to collapse into a black hole. It has to be 10-15 times the sun after the explosion. Still, with this one at a whopping 20-40, it's quite likely that it'll be black hole.

    • Re:Impending black hole? (Score:4, Informative)

      by mcfiddish ( 35360 ) on Thursday January 09, 2003 @04:35PM (#5050308)

      So, is this a black hole waiting to happen?
      It depends on what's left after the supernova explosion. If the mass of the remnant is less than 1.4 solar, it's a white dwarf. If it's more than 1.4 and less than 3.2 solar, it's a neutron star. If it's more than 3.2 solar, it's a black hole
  • You mean that Rho Cas has already imploded and exploaded. The light FROM the said explosion will reach us in the near future. Since Rho Cas is 10,000 light years away.. it probably exploded 9,980 years ago? how long is the "near future?"

  • Now to locate it (Score:3, Informative)

    by Shamanin ( 561998 ) on Thursday January 09, 2003 @04:46PM (#5050423)
    location [akamaitech.net]

    If only we could mount some lasers on stars to project those helpful constellation lines.
    • If only we could mount some lasers on stars to project those helpful constellation lines.

      Actually, Cassiopeia is one of those "can't miss it" constellations, lines or no lines. Just look for five stars arranged in a big "W" overhead. They're all pretty bright stars, too, so you can find them easily even if you live in the middle of the city.

      Now finding the actual nova candidate in question, that's more of a challenge. You can estimate the place where it should be, but actually seeing it is going to take a clear dark sky. Which are getting harder and harder to find, these days, unless you go way out in the middle of nowhere, away from all city and road lights...

  • ...read Robert P. Kirshner's Our Extravagant Universe: Exploding Stars, Dark Energy, and the Accelerating Cosmos [amazon.com]. Quite an excellent read, if I do say so myself.

    Posted with Safari build 51 [apple.com].

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