M58 (NGC 4579) Observing Guide — Barred Spiral Galaxy in Virgo

Overview

M58 is a barred spiral galaxy in Virgo, catalogued as NGC 4579. At magnitude 9.7 and roughly 60 million light-years away, it is the brightest spiral galaxy in the Virgo Cluster — an important distinction in a cluster otherwise dominated by elliptical and lenticular galaxies. Its active nucleus makes it a member of the LINER (Low-Ionization Nuclear Emission-line Region) galaxy class.

Barred spiral galaxies carry a central bar of stars from which the spiral arms originate. In M58, the bar is subtle visually but clear in detailed images.

Basic Data

Physical Characteristics

M58 lies about 60 million light-years away and glows at magnitude 9.7. Its bright nucleus and moderately high surface brightness make it one of the more detectable spiral galaxies in the Virgo Cluster, despite lying at the same distance as its elliptical neighbors. An active central nucleus contributes additional luminosity to the core.

Observing Guide

Finding It

M58 sits in the eastern Virgo Cluster and transits around 8–10 PM in spring. It lies a few arcminutes south-southeast of the 6th-magnitude star 20 Virginis, making it relatively easy to pinpoint compared to galaxies in the more crowded cluster core. The bright compact core is the first thing to identify.

Observing Tips

The bright, compact nuclear region is immediately apparent even at moderate aperture. A 150mm or larger instrument under dark skies begins to show the halo surrounding the core — the disk of the spiral galaxy. The bar structure requires imaging or very large aperture to confirm visually.

Recommended Equipment

A medium telescope with 80–100mm aperture detects M58 from a dark site. Moving to 150mm improves the view of the halo and makes the galaxy feel three-dimensional rather than just a bright dot.

Astrophotography Tips

Tracked long exposures reveal M58's bright bar and faint outer spiral arms. Pairing M58, M59, and M60 in the same wide-field composition creates a scientifically interesting portrait of Virgo Cluster galaxy diversity — spiral, elliptical, and giant elliptical in a single frame.

Summary

M58 is the Virgo Cluster's standout spiral galaxy — the brightest of its type among the cluster's Messier members, and an active galactic nucleus with scientific significance. For spring observers completing the Virgo Cluster sequence, M58 provides a satisfying spiral counterpoint to the region's many ellipticals.