.. _sphx_glr_api_gallery_astro_stellar_structure:

Stellar structure
-------------------

Polytropic gas spheres, the Chandrasekhar mass limit, the mass-luminosity
relation, and the nuclear reactions that power a star, from
:mod:`physicskit.astro.stellar_structure` (and, for nucleosynthesis,
:mod:`physicskit.particle.nuclear`).


.. raw:: html

  <div id='sg-tag-list' class='sphx-glr-tag-list'></div>


.. raw:: html

    <div class="sphx-glr-thumbnails">

.. thumbnail-parent-div-open

.. raw:: html

    <div class="sphx-glr-thumbcontainer" tooltip="Lane (1870) first treated a star as a self-gravitating polytropic gas sphere, Ritter (1878-1889) generalized the analysis to arbitrary polytropic index n, and Emden (1907) systematized the resulting family of solutions to the dimensionless equation">

.. only:: html

  .. image:: /api/gallery/astro/stellar_structure/images/thumb/sphx_glr_plot_01_lane_emden_polytropes_thumb.png
    :alt:

  :doc:`/api/gallery/astro/stellar_structure/plot_01_lane_emden_polytropes`

.. raw:: html

      <div class="sphx-glr-thumbnail-title">Lane-Emden polytropes: Lane, Ritter, and Emden's gas spheres</div>
    </div>


.. raw:: html

    <div class="sphx-glr-thumbcontainer" tooltip="Chandrasekhar (1931) showed that electron degeneracy pressure cannot support an arbitrarily massive white dwarf: as the star&#x27;s mass grows, the degenerate electrons are forced relativistic, softening the pressure-density relation until, above a critical mass, no equilibrium exists at all,">

.. only:: html

  .. image:: /api/gallery/astro/stellar_structure/images/thumb/sphx_glr_plot_02_chandrasekhar_mass_thumb.png
    :alt:

  :doc:`/api/gallery/astro/stellar_structure/plot_02_chandrasekhar_mass`

.. raw:: html

      <div class="sphx-glr-thumbnail-title">Chandrasekhar's white dwarf mass limit</div>
    </div>


.. raw:: html

    <div class="sphx-glr-thumbcontainer" tooltip="Eddington (1924) showed that a main-sequence star&#x27;s luminosity is fixed almost entirely by its mass, regardless of what actually generates the star&#x27;s energy -- fifteen years before Bethe worked out the nuclear reactions responsible:">

.. only:: html

  .. image:: /api/gallery/astro/stellar_structure/images/thumb/sphx_glr_plot_03_eddington_mass_luminosity_thumb.png
    :alt:

  :doc:`/api/gallery/astro/stellar_structure/plot_03_eddington_mass_luminosity`

.. raw:: html

      <div class="sphx-glr-thumbnail-title">Eddington's mass-luminosity relation</div>
    </div>


.. raw:: html

    <div class="sphx-glr-thumbcontainer" tooltip="Fifteen years after Eddington&#x27;s mass-luminosity relation described the consequences of a star&#x27;s energy output without explaining its source, Bethe (1939) worked out the two nuclear fusion chains that actually power it: the proton-proton (pp) chain, dominant in Sun-like stars, and the carbon-nitrogen-oxygen (CNO) cycle, dominant in hotter, more massive stars. Both fuse four hydrogen nuclei into one helium-4 nucleus,">

.. only:: html

  .. image:: /api/gallery/astro/stellar_structure/images/thumb/sphx_glr_plot_04_bethe_nucleosynthesis_thumb.png
    :alt:

  :doc:`/api/gallery/astro/stellar_structure/plot_04_bethe_nucleosynthesis`

.. raw:: html

      <div class="sphx-glr-thumbnail-title">Bethe's pp-chain and CNO cycle: the energy source of stars</div>
    </div>


.. thumbnail-parent-div-close

.. raw:: html

    </div>


.. toctree::
   :hidden:

   /api/gallery/astro/stellar_structure/plot_01_lane_emden_polytropes
   /api/gallery/astro/stellar_structure/plot_02_chandrasekhar_mass
   /api/gallery/astro/stellar_structure/plot_03_eddington_mass_luminosity
   /api/gallery/astro/stellar_structure/plot_04_bethe_nucleosynthesis