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  1. Senior Member
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    #1

    Stellar Classification - Part 2: "How a star gets its color"

    Hello, this is part two of my too-long-post. The purpose is to teach myself how to write something worth reading. Although this is "part two", it is meant to be a standalone post as well.
    Could you please tell me which parts of the text need improvement?

    Stars vary in size, mass, brightness, temperature, age, and color. Trying to look for correlations and patterns in these intertwined stellar properties is difficult - there’s just too much data. But it all became much easier once we figured out how a star gets its color.

    What our brains interpret as blue is light at a short wavelength (~450 nm). Light at a longer wavelength (~650 nm) is perceived as red. Shorter wavelengths allow the electromagnetic wave to have more densely-packed peaks, compress the photons that comprise it, and consequently carry more energy. Blue must, therefore, be produced by a high-energy source, and the source of red must be low-energy. That energy can be thought of as heat, and radiating light is a way to dissipate it.

    It's worth noting that most of the light coming from objects around us is not produced by them. When light falls on an object, a portion of its spectrum is absorbed, and the remaining portion that is reflected is seen as the light’s hue.

    Body heat is high enough for humans to radiate in infrared. Embers are hot enough to radiate in what our eyes register as dim red. An old lightbulb, soon to be past due, shines in orange-yellow because its filament can't be heated enough to produce the bright, white light that it used to produce when it was brand new. The temperature of a lightning bolt reaches the ranges of astounding 25,000°K, making it blue. And the sun, with the surface temperature of over 5,700°K, is bright white. Nonetheless, most of the blue in the sunlight’s spectrum is scattered through the atmosphere, so from Earth, it appears yellow-white, and even deep orange during sunset.

    The color of a star is directly connected to its temperature - the hotter the star, the shorter the wavelength. Stars are heated from the inside by their source of energy, the stellar core. This means that the color of a star allows us to determine what’s happening inside. Thus, the color of the star correlates with its other properties.

    Last edited by Glizdka; 01-Jul-2019 at 10:47. Reason: A comma asked me to join the text since nobody's replied yet.

  2. teechar's Avatar
    Moderator
    English Teacher
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    #2

    Re: Stellar Classification - Part 2: "How a star gets its color"

    Quote Originally Posted by Glizdka View Post
    Body heat is high enough has sufficient energy for humans to radiate in infrared. Embers are hot enough to radiate in what our eyes register as dim red. An old lightbulb, soon to be past due, shines in orange-yellow because its filament can't be heated enough to produce the bright, white light that it used to produce when it was brand new. The temperature of a lightning bolt reaches the ranges of an astounding 25,000°K, making it blue. And the sun, with the a surface temperature of over 5,700°K, is bright white. Nonetheless, most of the blue in the sunlight’s spectrum is scattered through the atmosphere, so from Earth, it appears yellow-white, and even deep orange during sunset.
    ,

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