M40 (Winnecke 4) Complete Guide — Double Star in Ursa Major

Overview

Winnecke 4 (M40) is a Double Star located in Ursa Major, cataloged as WNC 4. With an apparent magnitude of 8.4, it lies About 510 light-years from Earth. This Intermediate-level object is best observed in the Spring sky.

This is one of the objects cataloged in the Messier catalog.

Basic Data

Physical Characteristics

Located About 510 light-years from Earth with an apparent magnitude of 8.4.

Observation Guide

How to Find

Winnecke 4 (M40) is located in the Ursa Major region. It transits around 20:00–22:00 during Spring, making it well-positioned for observation. use the main stars of Ursa Major as guide stars and confirm the exact position with a star chart or app.

Observation Tips

Observation with a telescope is recommended.

Recommended Equipment

We recommend observing from dark skies with a telescope of 80mm aperture or more.

Astrophotography Tips

For photographing Winnecke 4 (M40), prime-focus astrophotography with a camera attached to a telescope is recommended. Use a tracking mount and appropriate exposure times.

Summary

M40 is a Double Star observable in Ursa Major, rated Intermediate level. Enjoyable with a small telescope, it is one of the most popular Messier objects for observation. Try observing it in the Spring night sky!