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Open cluster · Sagittarius

NGC 6546

Deep skyNGC 6546

Scientific overview

NGC 6546 is an open cluster in the constellation Sagittarius. It shines at apparent magnitude 8 and spans about 6.9 arcminutes of sky.

Observation guide

Difficulty
Small telescope
Recommended equipment
≈ 80–100 mm telescope
Best observed
Summer (S. evening sky)
Best hemisphere
Southern

Guidance follows standard observing practice, derived from the object's real magnitude and position. A dark, moonless sky always helps.

Location in the sky

Constellation
Sagittarius
RA / Dec
18.1229h / -23.2962°
Hemisphere
Southern
Season
Summer

Precision measurements

Distances and velocities from SIMBAD · NGC 6546

Distance3,082 lySIMBAD · catalogued
Physical size (major axis)6.186327 lySIMBAD · derived
Radial velocity-29.427 ± 1 km/sSIMBAD · measured
Right ascension (ICRS)271.841667 degSIMBAD · measured
Declination (ICRS)-23.296667 degSIMBAD · measured
Full field-level provenance
  • Distance: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · mesDistance · dist · 2017AstBu..72..257L · catalogued value · source value 945 pc · retrieved 2026-07-11
  • Physical size (major axis): Centre de données astronomiques de Strasbourg (CDS) · derived (OpenNGC angular size × SIMBAD distance) · physical size = angular size × distance (small-angle); angular size from OpenNGC, distance from SIMBAD mesDistance · derived · retrieved 2026-07-11
  • Radial velocity: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · rvz_radvel · 2014A&A...562A..54C · direct catalogue measurement · retrieved 2026-07-11
  • Right ascension (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · ra · 2009MNRAS.399.2146W · direct catalogue measurement · retrieved 2026-07-11
  • Declination (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · dec · 2009MNRAS.399.2146W · direct catalogue measurement · retrieved 2026-07-11

Physical size is derived from the OpenNGC angular size and the catalogued distance (small-angle: size = angle × distance). This is a Galactic object: its Doppler shift is shown as a radial velocity, not a cosmological redshift. Fields a source did not provide are omitted, never invented.

ObjectTypeMagSize (′)
M 25M 25Open cluster4.614.1
NGC 6530NGC 6530Cluster with nebulosity4.66
M 23M 23 · NGC 6494Open cluster5.516.8
Lagoon NebulaM 8 · NGC 6523Nebula5.845
M 21M 21 · NGC 6531Open cluster5.96
M 22M 22 · NGC 6656Globular cluster6.1712.6
M 55M 55 · NGC 6809Globular cluster6.4912
M 18M 18 · NGC 6613Open cluster6.96

Sources

The primary and reference sources this topic draws on.

  • OpenNGCOpenNGC (M. Verga) — NGC/IC, Messier, and Caldwell catalogue data

    Openly-licensed deep-sky catalogue: object types, positions, magnitudes, sizes, morphology, and cross-identifiers.