Observing · Overview

This section covers the practical fundamentals of ground-based observing: atmospheric seeing and transparency, the visibility of objects as determined by latitude and declination, site selection and observation planning, and visual observing techniques. It marks the start of the hands-on observing path and provides the basis for later visual work and imaging.

What this section covers

Atmosphere and Observing Conditions Seeing, transparency, light pollution and the Bortle scale, extinction, moonlight, and humidity.

Hemisphere Visibility Principles Use latitude and declination to tell whether an object is visible or circumpolar.

Site Selection and Observation Planning Dark, steady, clear sites; light-pollution maps, Clear Sky Charts, and target lists.

Visual Observing Techniques Dark adaptation, averted vision, magnification and exit pupil, filters, and star-hopping.