Stars & the Deep Sky · Overview
This section covers the principal subjects of deep-sky imaging: the physical properties of stars, the systems used to name and catalog them, and the star clusters, nebulae, and galaxies they form. It begins with stellar evolution and proceeds to the classification and observation of each type of deep-sky object, providing the basis for identifying and interpreting these targets.
What this section covers
Section titled “What this section covers” Stellar Physics and the H–R Diagram Spectral classification, the H–R diagram, and mass-dependent stellar evolution.
Notable Stars and Stellar Nomenclature Bayer, Flamsteed, variable-star and IAU naming systems, plus the brightest stars.
Double, Multiple, and Variable Stars Measuring mass from binary orbits, and eclipsing, pulsating, and cataclysmic variables.
Star Clusters Open vs. globular clusters, dating via the H–R turnoff, and membership.
Nebulae Emission, reflection, planetary, dark, and remnant nebulae, and narrowband imaging.
Galaxies Hubble classification, galaxy structure, active galactic nuclei, and clusters.
A Guide to Notable Deep-Sky Objects A quick reference to the deep-sky objects most often imaged by amateurs.