• uis@lemm.ee
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    4 months ago

    Mass in seconds? How? I get mass in Joules, but seconds?

    • Eiri@lemmy.ca
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      4 months ago

      There are two possibilities I can think of:

      • Orbit duration can be used to calculate mass
      • The diameter of a star or the parallax distance on the sky (in arcseconds) can also be used to evaluate mass
        • Eiri@lemmy.ca
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          3 months ago

          I thought stars of similar masses were also of similar sizes. They’re not?

          • Lifter@discuss.tchncs.de
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            3 months ago

            I’m no astrologer but from what I’ve learned, we also need to look at the color to glassify stars into categories. It varies a bit though in each category so it’s a blunt tool.

            Then there are other objects like gas clouds and even galaxies. For those, we have no idea of the density distribution, so radial size gives us even less info.