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AsteriaStar
Open cluster · Vulpecula

NGC 6940

Deep skyNGC 6940

Scientific overview

NGC 6940 is an open cluster in the constellation Vulpecula. It shines at apparent magnitude 6.3 and spans about 10.8 arcminutes of sky.

Observation guide

Difficulty
Binoculars
Recommended equipment
10×50 binoculars or any small telescope
Best observed
Summer (N. evening sky)
Best hemisphere
Northern

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
Vulpecula
RA / Dec
20.5741h / 28.2827°
Hemisphere
Northern
Season
Summer

Precision measurements

Distances and velocities from SIMBAD · NGC 6940

Distance3,591 lySIMBAD · catalogued
Physical size (major axis)11.281402 lySIMBAD · derived
Radial velocity7.7 ± 0.1 km/sSIMBAD · measured
Right ascension (ICRS)308.625833 degSIMBAD · measured
Declination (ICRS)28.278056 degSIMBAD · measured
Full field-level provenance
  • Distance: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · mesDistance · dist · 2021A&A...651A.104P · distance indicator: paral · catalogued value · source value 1101 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 · 2017A&A...600A.106C · direct catalogue measurement · retrieved 2026-07-11
  • Right ascension (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · ra · 2021A&A...647A..19T · direct catalogue measurement · retrieved 2026-07-11
  • Declination (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · dec · 2021A&A...647A..19T · 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 (′)
NGC 6823NGC 6823Cluster with nebulosity7.16
Dumbbell NebulaM 27 · NGC 6853Planetary nebula7.46.7
NGC 6830NGC 6830Open cluster7.94.2
NGC 6802NGC 6802Open cluster8.84.5
NGC 6882C 37 · NGC 6882Open cluster14.17.5

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.