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Space Science

Stars Have a Weight Limit 83

Posted by timothy from the or-they-can't-wrestle dept.
Mike writes "Using NASA's Hubble Space Telescope, astronomers made the first direct measurement within our Milky Way Galaxy, and concluded stars cannot get any larger than about 150 times the mass of our sun. The astronomers used the Hubble to probe the Arches cluster, the densest in our galaxy. This finding takes astronomers closer to understanding the complex star formation process. It also gives the strongest backing yet to the notion stars have a weight limit."
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Stars Have a Weight Limit More

Stars Have a Weight Limit

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  • Last I checked (Score:1, Informative)

    by FuturePastNow ( 836765 )
    mass and weight- not the same thing.

  • Disagree (Score:5, Funny)

    by Ghetto_D ( 670850 ) on Wednesday March 09, 2005 @04:30PM (#11893566)
    I disagree, Stars have no weight limit

    http://www.starjones.com/ [starjones.com]

    //I'm awful, I know

  • Proven false (Score:4, Funny)

    by Dram ( 149119 ) <grant@henninger.name> on Wednesday March 09, 2005 @04:35PM (#11893629) Homepage
    Clearly Kirstie Alley is proving this false.
    • Too bad the Hubble program is being scrapped. This was one of the important space programs that has taught us the most. But leave it to bureaucrats to screw everything up.
      • Hubble = huge waste of money and resources which could be used in another space project with better results.
        • Waste of money? How so?
          • Because it is over priced and outdated.

            At the time it was a sound investment, but it would be cheaper now days to set up a very large array [wikipedia.org] type thing with low quality recievers on commercial sats. Then you can just take the raw data you get back and throw in into a SETI@home type thing to combine the feeds.
            • Funny U provided a link, I live near the VLA. Not sure if there are efficient visual-radiation arrays. Or how effective they would be in space. I know the hubble has taken duplicate images from opposite sides of our orbit with the sun to find parallax. Not sure if for image enhancement though. Maybe you know more about this? And are U saying we did'nt have the computing power when the hubble was launched? I know the seti-soft. was designed withing a few years of the hubble, and NASA probably has a mu
    • Nice.

  • Else (Score:5, Funny)

    by Dolly_Llama ( 267016 ) on Wednesday March 09, 2005 @04:39PM (#11893659) Homepage
    concluded stars cannot get any larger than about 150 times the mass of our sun.

    Else they have to pay for two seats.

    • You know, airlines could get around discrimination charges by charging _everyone_ by weight. Just make price a function of weight (e.g., fixed base price plus quadratic weight charge). The weight itself, and even price, perhaps, can be confidential to protect people with fragile and weak egos.

      • That still discriminates against fat people, but they would still pay more than skinny people to fly.
        • Hmm, last I checked, gravity discriminates against fat people.

          The airlines pay more per individual for people who weigh more (including me at 190cm over my girlfriend at 154cm) in decreased gas mileage (or is it mile gaseage in airplanes?). So why shouldn't a heavier individual pay more?

          Well, currently I think they take an average and base their rates on that average. It's just as effective for them, only light people see it as unfair that they have to pay for the "extra" on the other end of the scale (

          • Re:Else (Score:3, Funny)

            by ekuns ( 695444 ) *

            Hmm, last I checked, gravity discriminates against fat people.

            Gravity doesn't discriminate against fat people. It pulls on them too. Just imagine if all you had to do to avoid gravity was gain weight. (Wait a minute...)

      • The airlines aren't charging you by weight, they are charging by space. Know why the 1st class seats cost more? Because you're taking more space (they can carry less passengers).

        If you're such a fat bastard that you can't squeeze into a single seat, they lose money by you taking a second seat (for the airfare lost).

  • Just think, won't be able to say this much longer: (Score:5, Insightful)

    by sgant ( 178166 ) on Wednesday March 09, 2005 @04:41PM (#11893673) Homepage Journal
    "Using NASA's Hubble Space Telescope...

    Yeah, in the very near future, they'll say "wow, if only we had an orbiting telescope..."

    Back to the stone-ages for us!

  • hmmm (Score:4, Funny)

    by crimson_1190 ( 831533 ) on Wednesday March 09, 2005 @04:41PM (#11893676)
    I think Anna Nichole smith has proved that one wrong. she hasn't lost weight, mearly collapsed in on herself
  • Because if you go from star to not-star, you gain weight. If you want to be a star again, you better lose the weight [sho.com]. So stars must have a weight limit.

  • 150 solar mass -- not a hard limit (Score:5, Interesting)

    by helioquake ( 841463 ) on Wednesday March 09, 2005 @04:48PM (#11893787) Journal
    I've said this on other forums but...

    That 150 solar mass limit is not a hard limit. There will be some statistical probability to find a star greater than 150 solar mass. Figer's finding indicates that he could not find a star any more massive than 130 solar mass (in the Archer cluster? is that the pistol star again?).

    This will be an observational constraint for stellar model parameter. Any future stellar evolution theory has to take into account that there are very few number of stars that have a mass greater than 130 solar mass, and none above 150 solar.

    [Hey, some stellar evolution scientists would tell you today that there can't be a star any more massive than 80 solar mass! This topic is still debated for its accuracy. So take it with a grain of salt.]
    • This will be an observational constraint for stellar model parameter. Any future stellar evolution theory has to take into account that there are very few number of stars that have a mass greater than 130 solar mass, and none above 150 solar.

      I, for one, am eagerly awaiting the slashdot headline that will read "Distant galaxy made up of stars 200 times the size of our sun discovered".

      Never trust a scientist that tells you something is impossible, there's another out there waiting for him to die so he can
      • You should look up the Nature article. The author himself is more cautious in the main text (c.f., his abstract says a bit firmly). And you will understand why the number 150 solar mass came about.

      • The human body used to be said to be unable to survive a speed (yes, speed) of more than 30 kph, etc.

        Depends on the direction of the vector... if it's pointing towards the center of the earth, then no, you seem to encounter a hard object called the ground and go SPLAT!!! If you're lucky, you'd break a few bones. If not, then of course you wouldn't survive...

        Same applies to the opposite direction, you would eventually run out of breathable air, after 1 hour...

        If you're attempting to go 30kph in the dir
      • ...is impossible.

        Never trust a reader to correctly interpret a story posted on /. that is a misunderstood link to a pop science report about a paper published by a scientist. I think the scientists themselves are doing fine without the /. commentary on how they could do their job better.

    • Re:150 solar mass -- not a hard limit (Score:5, Interesting)

      by 4of12 ( 97621 ) on Wednesday March 09, 2005 @05:09PM (#11894033) Homepage Journal

      That 150 solar mass limit is not a hard limit.

      Bottom of TFA also cautions that.

      So, all this prompts me to come up more stupid questions of

      • what the lower mass limits are, or, more generally,
      • what does the star mass distribution function look like?
      • How does that star mass distribution function vary or correlate with star age?
      • Has anyone come up with theoretical models for energy production in stars that explains the distribution of observed star masses and observed star energy output?

      OK, I'll stop asking questions now.

      • Re:150 solar mass -- not a hard limit (Score:5, Informative)

        by wanerious ( 712877 ) on Wednesday March 09, 2005 @05:46PM (#11894437) Homepage
        Those are excellent questions:

        a) Lower limits are roughly 1/20 solar mass. Less mass than this can't product the temperatures and densities needed for hydrogen fusion.

        b) roughly the population dies off as M^{-2.5}, with some hard cut-off at high and low mass. There are many more low- than high-mass stars.

        c) Age goes roughly as M^{-3.5} or so. High mass stars don't live very long at all.

        d) Yes! Not only energy output, but elemental abundance evolution. That was my thesis.

  • Reading the article... (Score:3, Funny)

    by jd ( 1658 ) <imipakNO@SPAMyahoo.com> on Wednesday March 09, 2005 @04:51PM (#11893819) Homepage Journal
    It does NOT say that stars over 150 solar masses can't exist, only that the cluster is missing them. So, if the Anonymous Coward who walked off with them would own up, everything would be ok.
    • It does NOT say that stars over 150 solar masses can't exist, only that the cluster is missing them. So, if the Anonymous Coward who walked off with them would own up, everything would be ok.

      I just found him! Boy, was he blushing--oh wait, those were the third-degree burns he got from carrying those giants. Nevermind...

  • Article says (Score:5, Funny)

    by Profane MuthaFucka ( 574406 ) <busheatskok@gmail.com> on Wednesday March 09, 2005 @04:59PM (#11893914) Homepage Journal
    Regarding the cluster that was studied:

    "It resides 25,000 light-years away from Earth in our galaxy's hub"

    Ahhh, it's an unswitched star topology network.

  • well (Score:4, Interesting)

    by Joe the Lesser ( 533425 ) on Wednesday March 09, 2005 @05:02PM (#11893959) Homepage Journal
    Wouldn't any accumulation of mass about that size that's not a star be a black hole?

    And the larger the star the shorter it's life span, so if a star gathers too much mass in it's forming stages will it just become a black hole beforehand or lose weight and then begins it's short life span normally?
    • IANAAP (I am not an astrophysicist), but there are other risks for a massive star other than collapsing. If they are rotating too fast then the fusion reaction starting could simply blow them apart.
    • The gravitational field of a star increases with mass. So a really massive star (approaching the x150 limit) will burn very quickly to maintain equilibrium. At some point the star will eventually run out of hydrogen and blow itself out (a super nova) collapsing into a white dwarf and finally a black hole.

      A star beyond the 150 limit could therefore reach the super nova stage instantly.

      • Small correction... (Score:4, Informative)

        by MattHaffner ( 101554 ) on Wednesday March 09, 2005 @10:56PM (#11896522)
        A white dwarf is the remnant from a low to mid-mass star (less than about 10 solar masses). White dwarves do not go supernova unless they have a very close binary companion that begins to dump mass onto its surface.

        As a side note, white dwarf+companion supernova have characterstics in their spectra that are different from those of a single massive star collapse. As a result, they are distinguished by the labels Type Ia (for the WD binary SN) and Type II (for most single massive star SN), Ib, and Ic (for oddball stars that have been modified before the SN occurs). The labels are a bit strange because SN were classified by spectra before the explanation for the difference in their spectra existed.

        Finally, although I'm not an expert in massive star formation, I think the 120-150 solar mass limit is not from a fast-burning argument, but from an argument that arises from looking at how such a massive system evolves dynamically in the early part of its life. Most massive stars have significant "winds" that slowly shed material from their envelops right from the start. It may be that such a process in stars with a chance to get larger end up disrupting the accretion process too fast.

    • Re:well (Score:3, Interesting)

      by ekuns ( 695444 ) *

      Wouldn't any accumulation of mass about that size that's not a star be a black hole?

      I think the issue is that if you start with a diffuse cloud whose mass is too great, as the inner part of the cloud collapses and starts to heat up and eventually grow, its radiation pressure on the cloud's dust particles will be greater than the force of gravity on those particles. The outer layers of the cloud will be blown into interstellar space. This causes a limit to the maximum mass of a star.

      You could pr

      • You could probably create a larger star then the limit spoken of in the article by merging two smaller ones [...] However, getting two stars to collide in such a way that they merge takes some doing.

        What the hell are you, a Pearson's Puppeteer or something?
  • I think I have to disagree with the term "direct measurment". To me, that sounds like they put the thing on a scale. And I'm pretty sure that there have been "direct measurement[s] within our Milky Way Galaxy" before. In fact, I weighed myself last night.

    What exactly do they consider direct versus indirect? I'm thinking that there are differing degrees of indirect measurement. From putting it on a scale, to measuring orbits of nearby objects, to red-shifts of light passing nearby.

    • Re:Direct measurement? (Score:3, Informative)

      by ekuns ( 695444 ) *

      What exactly do they consider direct versus indirect?

      The article at hubblesite [hubblesite.org] answers your question:

      Figer estimated the stars' masses by measuring the ages of the cluster and the brightness of the individual stars. He also collaborated with Francisco Najarro of the Instituto de Estructura de la Materia in Madrid, who produced detailed models to confirm the masses, chemical abundances, and ages of the cluster's stars. [ ... ] Astronomers must know the cluster's distance to reliably estimate th

    • The OP says "Mike writes, 'blah blah'", which doesn't provide proper attribution. The "blah blah" part then goes on to be a verbatim copy of the second through fifth sentences of the linked article.

      Makes me wonder of the /. eds slept through the part of high school where they teach you about plagiarism (this "Mike" guy evidently did).

  • Re: (Score:2, Interesting)

    by account_deleted ( 4530225 )
    Comment removed based on user account deletion
    • The article you link to could have been a bit more clear, but if you read carefully, notice that "large" is not referring to the mass of the star, but to its radius.

      A star only 15 times the mass of the sun can go through the red supergiant phase near the end of its life. However, this time is short in relation to the lifetime of the star. Finding the largest ones in the sky right now is more of a matter of catching a star at the right time rather than just of how massive it actually is.

    • Re:Uh, what??? (Score:1, Interesting)

      by Anonymous Coward

      "These stars are not the most massive known," noted Levesque. "They are only 25 times the mass of the sun, while the most massive stars may have as much material as 150 suns. Nor are they the most luminous, as they are only about 300,000 times the luminosity of the sun, not the factor of 5 million or so attributed to the most luminous stars. They aren't even the coldest stars known - brown dwarfs have such low temperatures that they can't even fuse hydrogen. But the combination of modestly high luminosities

  • "Standard theories predict 20 to 30 stars with masses between 130 and 1,000 solar masses," Figer explained. "But we found none. If they had formed, we would have seen them,"

    The stars have few fundamental parameters:

    - the surface temperarure
    - the accerlation
    - and the absolute magnitude

    These parameters depend on

    - the mass, radius, density, consistance and the rotation speed

    There are alot of unanswered questions but I think we have been surprised many times in the past ;)

    First we should understand the

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