M34 (open cluster in Perseus)

220: M34 Image

M34 was discovered by Giovanni Batista Hodierna before 1654, and re-discovered independently by Charles Messier on August 25, 1764. At about 180 million years old, M34 is a middle-aged open cluster, which has about 100 member stars, ranging from magnitude 7.9 down. Its full extent is a circle of about 35 arcminutes, or just a bit larger than the full moon. Its visual magnitude of 5.5 and surface brightness of 12.7 mean that it may be visible to the naked eye as a faint nebulosity under excellent seeing conditions and dark skies.

230: M34 with binoculars

The Astronomical League rates M34 as an “Easy” object with 7X50 binoculars, which indeed it is from Bullington. To locate M34 in your binocular, begin by locating Algol in Perseus and Almaak in Andromeda. With Algol centered in your view, swing your binocular toward Almaak until Algol is at the edge of the field. M34 is visible as a bright luminosity near the other edge of the field.

My 7X50s don’t quite resolve the cluster into individual stars except under perfect seeing conditions, but even 10X50s or a short-tube 80 will routinely resolve the individual stars. In anything larger, the view is even more impressive. Using a low-power eyepiece, the scopes most of us use will resolve about 80 member stars in the cluster, with about two dozen bright central stars in a 10 arcminute circle, and many dimmer stars filling out the remaining extent of the cluster. Many of those stars are doubles, and are worth exploring on their own.

240: M34 Telrad with Telrad

M34 is also easy to find in your telescope. Start with your Telrad centered on Algol in Perseus. Swing your scope on a line toward Almaak in Andromeda until Algol is on the edge of the 4-degree circle. Continue on the same line for another three-quarters of a Telrad field. M34 lies one degree north of the Algol->Almaak line on-center with your Telrad, right on the 2-degree circle.

SEDS M34 Page

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