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- Sky2Pix_Mercator

# Sky2Pix_Mercator

class astropy.modeling.projections.Sky2Pix_Mercator(*args, **kwargs)

  Bases: `Sky2PixProjection`, `Cylindrical`

  Mercator - sky to pixel.

  Corresponds to the `MER` projection in FITS WCS.

  \[\begin{split}x &= \phi \\ y &= \frac{180^{\circ}}{\pi}\ln \tan \left(\frac{90^{\circ} + \theta}{2}\right)\end{split}\]