M34 is a fine large loose open cluster located in the constellation of Perseus. At magnitude +5.5, it's visible as a faint smudge to the naked eye (from a reasonably dark site) and is easily identifiable with binoculars, where the brightest members are resolvable. A small telescope reveals up to 20 bright stars embedded in nebulosity with about 80 members visible in large amateur scopes.

M34 was probably discovered by Giovanni Batista Hodierna sometime before 1654. Charles Messier rediscovered it on August 25, 1764. He then included it in his catalogue describing it as, "A cluster of small stars a little below the parallel of γ (gamma) And. In an ordinary telescope of 3 feet one can distinguish the stars". M34 along with Little Dumbbell Nebula (M76) are the only Messier objects in Perseus. Finding this open cluster is easy. It's positioned on the western side of Perseus next to the Andromeda boundary and only 5 degrees northwest of famous eclipsing binary star, Algol. M34 lies about halfway along a line connecting Algol with beautiful telescopic multiple star, Almach.

M34 Open Cluster (credit:- ESO)

Finder Chart for M34 (credit:- freestarcharts)

Finder Chart for M34 - pdf format (credit:- freestarcharts)

As previously mentioned, M34 is faintly visible to the naked eye and a fine binocular object. It's a large cluster that covers 35 arc minutes of apparent sky, which is more than that of the full Moon. When viewed through a small 80mm (3.1-inch) telescope, the brighter stars of the cluster appear prominent with many fainter members also visible especially when using averted vision. At low powers, the cluster nicely fills a good portion of the eyepiece field of view. Towards the center are a couple of double stars. Through a 150mm (6-inch) or 200mm (8-inch) scope, dozens of stars are revealed and the loose scattered look of the cluster is pronounced. The bright stars towards the centre of the group form three arms that radiate outwards in a distinct "Y" or "V" shape.

M34 is about 200 Million years old, which is much older than the two components of the Double Cluster in Perseus (NGC 869 and NGC 884 - 5.6 and 3.2 million years old respectively), the famous Pleiades (M45) cluster (115 million years old) but younger than the Hyades cluster (625 million years old).

The cluster contains up to 400 stars of which at least 19 members have been identified as white dwarfs. It's best seen from the Northern Hemisphere during October, November and December.

M34 Data Table

Object TypeOpen cluster
Distance (light-years)1,500
Apparent Mag.+5.5
RA (J2000)02h 42m 07s
DEC (J2000)+42d 44m 46s
Apparent Size (arc mins)35 x 35
Radius (light-years)7.5
Age (years)200 Million
Number of Stars>80
Other NameCollinder 31

Sky Highlights - July 2017

The Planets
This Month's Guide

Algol Minima
Algol eclipse dates and times for July

Meteor Shower
Southern Delta Aquariids (Aquarids) meteor shower peaks on July 29

Northern Hemisphere
West:- Mercury (mag. -0.5 to +0.3) (second half of month)
Southwest:- Jupiter (mag. -2.0)
South:- Saturn (mag. +0.2)
West:- Jupiter
South:- Saturn
East:- Neptune (mag. +7.8)
Southwest:- Saturn
South:- Neptune
Southeast:- Uranus (mag. +5.8)
East:- Venus (mag. -4.1)

Southern Hemisphere
West:- Mercury (second half of month)
Northwest:- Jupiter
East:- Saturn
West:- Jupiter
North:- Saturn
East:- Neptune
West:- Saturn
North:- Neptune
Northeast:- Venus, Uranus

Deep Sky

Small telescopes:-
Messier 13 - M13 - Great Hercules Globular Cluster
Messier 92 - M92 - Globular Cluster
Messier 11 - M11 - The Wild Duck Cluster (Open Cluster)
Messier 7 - M7 - The Ptolemy Cluster (Open Cluster)
Messier 6 - M6 - The Butterfly Cluster (Open Cluster)
Messier 4 - M4 - Globular Cluster
Messier 8 - M8 - Lagoon Nebula (Emission Nebula)
Messier 16 - M16 - Eagle Nebula (Emission Nebula with Open Cluster)
Messier 20 - M20 - Trifid Nebula (Emission and Reflection Nebula)

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