Galaxy · in Andromeda

Andromeda Galaxy

The nearest large spiral galaxy, about 2.5 million light-years away. The light you see left it long before there were humans. Also catalogued as M31.

When to look: Autumn evenings, roughly September to December.

What it looks like

Described as seen by eye at the eyepiece, on a clear night. Photographs collect light for minutes or hours and show far more colour and detail.

With the naked eye: From a dark site, an elongated smudge of light. It is not visible from city centres.
Small telescope (60-90 mm): A bright oval core fading outward. A wide field of view shows it best, so binoculars and small telescopes do well.
Medium telescope (114-150 mm): The core and a longer glow, its companion galaxies M32 and M110, and at a dark site a hint of a dust lane.
Large telescope (200 mm and up): Dust lanes at a dark site. The galaxy is larger than the field of view of most telescopes.

City or dark sky

From a city

From a city, usually only the core is visible, if at all.

From a dark site

A dark sky transforms the view. This target rewards a trip out of town.

Observing tip: Use your lowest magnification. It spans more sky than the full Moon but is faint, so give your eyes 20 minutes to adapt to the dark.