Look at any deep-sky map of the spring sky, and it's pretty clear that when it comes to galaxy hunting, the constellations of Coma Berenices and Virgo are the places to be. The Virgo Cluster hosts an estimated 1,300 individual galaxies (though some sources suggest it may have as many as 2,000) and forms the heart of the Local Supercluster, of which our Milky Way’s Local Group is considered an outlying member.

Of those 1,300+ galaxies, two of the brightest are M84 and M86, found not far from the Virgo Cluster's geometric center. Both shine at about 10th magnitude, bringing them within the grasp of 40-mm binoculars under dark skies.  The sketch below shows them through my 10x50 binoculars. They are separated in our sky by a scant 20 arc-minutes, making them look more like a faint, fuzzy double star than a pair of extragalactic targets.  Even after careful study, it's hard to tell their true identity through binoculars.

Studies show, however, that their twin appearance does not necessarily infer twin galaxies. While many sources continue to classify each as an elliptical galaxy, the most recent evidence indicates that M84 is actually one of those strange missing links, a lenticular galaxy. Also known as type S0 galaxies, lenticular galaxies share some of the traits of traditional spirals and other qualities found in elliptical systems. Lenticular galaxies contain very little interstellar matter and are made up of mostly old stars. Any dust is generally found only near the galactic core, not in outlying regions. Their spiral arms are difficult to make out even in deep photographs, which is why many refer to lenticular galaxies as "armless spirals."

Finding M84 and M86 with standard binoculars requires a bit of extra effort, as there are no bright stars in their immediate vicinity to guide the way. Start by centering your binoculars on Vindemiatrix (Epsilon [ε] Virginis), one of the brighter stars in Virgo. From there, shift your view about 5°—roughly one binocular field—west-southwest until you come across a pair of stars formed by 5th-magnitude Rho (ρ) Virginis and a fainter 7th-magnitude companion. M84 and M86 lie another 5° to the northwest of Rho.

Visualize a large, flattened triangle with its corners at Vindemiatrix, Rho Virginis, and the M84/M86 pair. This mental image can help you zero in on the galaxies’ approximate location. Spotting them through binoculars, however, may still prove challenging due to their low surface brightness and the lack of nearby stellar landmarks. To improve your chances, try using observing techniques such as averted vision, which takes advantage of your eye’s more light-sensitive peripheral vision. Steady your binoculars using a tripod or by bracing against a solid surface, and consider gently tapping the binocular barrel to introduce slight motion to the field. Subtle motion can help faint objects pop out against the background.

If you can find M84 and M86, then try your luck with the many other galaxies in the area, such as M87, which is shown the my sketch above. All of the Messier objects in the Virgo Cluster plotted on the chart above should be visible to patient observers using 50-mm or larger binoculars. Several NGC galaxies should be observable as well, although they are not plotted on the finder chart here.

Good luck with this month's Cosmic Challenge! And be sure to post your results in this column's discussion forum.

Until next month, remember that half of the fun is the thrill of the chase.  Game on!