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NGC 6539 — Globular Cluster in Serpens

Globular Cluster Good (46/100)
Magnitude 9.6m GlobularCluster Serpens (Ser) Visible
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1Properties

Magnitude 9.6
Angular Size 6.0′
no description

Position & Identifiers

RA 18h 04m 48.0s
Dec -07° 34' 60.0"
Constellation Serpens (Ser)
Catalog NGC 6539

2How easy to spot?

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Telescope Bortle 3 Bortle 4 Bortle 5
80mm refr. Medium+ Medium+ Medium
150mm Newt. Easy Easy Easy
C8 203mm Easy Easy Easy
Easy Medium Hard Very hard Impossible

Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs

Easy on Seestar S50

3Visibility

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Best season May – Jul (peak: Jun)

4 Eyepiece View

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125x TFOV: 0.4° Lim. mag: 13.6
N E

NGC 6539 · 6.0′ diameter · N up, E left

5 Best Magnification

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6 Classification Decoder

Nearby in the Sky

Other targets within a few degrees — pan your scope a little and keep exploring.

Visibility scores assume a 150 mm Newton at Bortle 4.

Tau Oph
HIP 88404; Tau Ophiuchi; 69 Ophiuchi
Hard+
Tight double — a rewarding split at 1.4″
Double Star mag 5.24 0.7° Ophiuchus
NGC 6517
Medium+
Globular cluster — dense ball of ancient stars
Globular Cluster mag 10.3 1.6° Ophiuchus
Y Oph
Medium
Pulsating variable, period 17.1d
Variable Star mag 6.21 3.3° Ophiuchus
NGC 6625
Easy
Open cluster
Open Cluster mag 9.0 6.2° Scutum
NGC 6535
Medium+
Compact globular cluster
Globular Cluster mag 10.6 7.3° Serpens
M14
NGC 6402
Easy
Globular cluster — dense ball of ancient stars
Globular Cluster mag 7.6 8.0° Ophiuchus
NGC 6366
Easy
Globular cluster — dense ball of ancient stars
Globular Cluster mag 10.0 9.5° Ophiuchus
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