NGC 559 is a magnitude +9.5 open cluster in Cassiopeia that's faintly visible with binoculars, but better seen with telescopes. The surrounding area of sky is full of bright clusters including NGC 457, M 52, M 103, NGC 129, NGC 7789, NGC 654, NGC 663 and IC 1848. As a result, tenth magnitude NGC 559 is not a standout object. However, it's easy to find and a nice target for small and medium size scopes.

NGC 559 (credit:- Roberto Mura)

William Herschel discovered NGC 559 on November 9, 1787. The cluster is positioned towards the eastern edge of the "W" of Cassiopeia and 3 degrees north of Ruchbah (δ Cas - mag. +2.7). To the southeast of NGC 559 are open clusters NGC 654 (mag. +6.5), NGC 663 (mag. +7.1), M 103 (mag. +7.4) and NGC 659 (mag. +7.9). From most northern temperate latitudes, NGC 559 is circumpolar and therefore visible all year round. It appears highest in the sky during October, November and December.

Finder Chart for NGC 559 (credit:- freestarcharts)

Finder Chart for NGC 559 - pdf format (credit:- freestarcharts)

Although visible with binoculars as a faint unresolved patch of light, NGC 559 is better seen with small and medium size scopes. A 100mm (4-inch) refractor reveals up to 15 stars superimposed on a grainy background. The brightest four stars are between 11th and 12th magnitude with another dozen between 13th and 14th magnitudes. In total, about 50 stars belong to the cluster, which spans 7 arc minutes of apparent sky. Larger apertures reveal many of the fainter stars.

NGC 559 is located 3,700 light-years distance and has a spatial diameter of 7 light-years. It's an old cluster with an estimated age of 2 billion years and is listed as number 8 in the Caldwell catalogue.

NGC 559 Data Table

NGC559
Caldwell8
Object TypeOpen Cluster
ConstellationCassiopeia
Distance (light-years)3,700
Apparent Mag.+9.5
RA (J2000)01h 29m 29s
DEC (J2000)63h 18m 30s
Apparent Size (arc mins)7 x 7
Radius (light-years)3.75
Age (years)2 Billion
Number of Stars50
Other NameCollinder 13

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

Southern Hemisphere
Evening
West:- Mercury (second half of month)
Northwest:- Jupiter
East:- Saturn
Midnight
West:- Jupiter
North:- Saturn
East:- Neptune
Morning
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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