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Planetary nebula · Ophiuchus

Box Nebula

Deep skyNGC 6309

Scientific overview

Box Nebula is a planetary nebula in the constellation Ophiuchus. It shines at apparent magnitude 11.5 and spans about 0.26 arcminutes of sky.

Observation guide

Difficulty
Large telescope
Recommended equipment
≈ 250 mm+ telescope
Best observed
Summer (evening sky)
Best hemisphere
Both (equatorial)

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
Ophiuchus
RA / Dec
17.2345h / -12.9106°
Hemisphere
Both
Season
Summer

Precision measurements

Distances and velocities from SIMBAD · NGC 6309

Distance9,025 lySIMBAD · catalogued
Physical size (major axis)0.68255 lySIMBAD · derived
Radial velocity-40 km/sSIMBAD · measured
Right ascension (ICRS)258.517948 degSIMBAD · measured
Declination (ICRS)-12.910526 degSIMBAD · measured
Full field-level provenance
  • Distance: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · mesDistance · dist · 2010ApJ...714.1096S · catalogued value · source value 2.767 kpc · 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 · 1999ApJ...515..610B · direct catalogue measurement · retrieved 2026-07-11
  • Right ascension (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · ra · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
  • Declination (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · dec · 2020yCat.1350....0G · 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 (′)
IC 4665Open cluster4.224.6
NGC 6633NGC 6633Open cluster4.612
M 10M 10 · NGC 6254Globular cluster4.989.3
rho Oph NebulaNebula5.160
M 19M 19 · NGC 6273Globular cluster5.577.5
M 14M 14 · NGC 6402Globular cluster5.739.9
M 12M 12 · NGC 6218Globular cluster6.0711.1
NGC 6235NGC 6235Globular cluster7.24.2

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.