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NGC 6642 — Globular Cluster in Sagittarius

Globular Cluster Good (45/100)
Magnitude 8.8m GlobularCluster Sagittarius (Sgr) Visible
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1Properties

Magnitude 8.8
Angular Size 3.9′
glob. cl. , pB, pL, iR, gpmbM rrr, st 16

Position & Identifiers

RA 18h 31m 54.0s
Dec -23° 28' 60.0"
Constellation Sagittarius (Sgr)
Catalog NGC 6642

2How easy to spot?

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Telescope Bortle 3 Bortle 4 Bortle 5
80mm refr. Easy Easy 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

Medium 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 6642 · 3.9′ 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.

M22
NGC 6656
Easy
Large bright globular cluster
Globular Cluster mag 5.1 1.1° Sagittarius
NGC 6638
Easy
Globular cluster — dense ball of ancient stars
Globular Cluster mag 9.2 2.0° Sagittarius
M28
NGC 6626
Easy
Globular cluster — dense ball of ancient stars
Globular Cluster mag 6.8 2.2° Sagittarius
21 Sgr
Hard+
Colorful double, sep 1.7″
Double Star mag 4.81 3.3° Sagittarius
NGC 6583
Easy
Open cluster
Open Cluster mag 10.0 3.9° Sagittarius
U Sgr
Medium
Pulsating variable, period 6.7d
Variable Star mag 6.68 4.4° Sagittarius
NGC 6717
Medium+
Compact globular cluster
Globular Cluster mag 10.35 5.4° Sagittarius
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