Open Clusters · Constellation Cancer

King Cobra Cluster (Messier 67 / NGC 2682)

Coordinates, Gaia DR3 distance (855 pc), 4.0 Gyr solar-twin age, exoplanet hosts, and observing guide for ancient open cluster M67 in Cancer.

Right Ascension (J2000.0)08h 51m 18.00s
Declination (J2000.0)+11° 48′ 00.0″
Primary ClassificationAncient open star cluster (solar-metallicity benchmark)
Best Observing SeasonLate Winter to Spring (February–May)

Provenance-Backed Scientific Measurements

Every measurement below preserves its unit, uncertainty interval, observational method, reference epoch, quality status, and primary catalog source. See Uncertainty & Provenance for how competing measurements are handled.

Astrometric, Photometric, and Physical Parameters for King Cobra Cluster (Messier 67 / NGC 2682)
ParameterValueUncertaintyMethod & EpochQuality StatusSource Archive
Integrated visual magnitude (V)6.1 mag± 0.1 magWide-aperture integrated photometrydefinitiveRevised New General Catalogue and Index Catalogue (RNGC/IC)
Heliocentric distance2790 ly± 40 lyGaia DR3 astrometric parallax of ~1,500 members (855 ± 12 pc) (J2016.0)definitiveESA Gaia Archive — Data Release 3
Apparent diameter30 arcmin± 2.5 arcminMember star-count boundaryhigh-confidenceRevised New General Catalogue and Index Catalogue (RNGC/IC)
Turnoff, asteroseismology & white-dwarf age4 Gyr± 0.2 GyrKepler K2 giant asteroseismology + Gaia DR3 turnoff & white-dwarf coolingdefinitiveESA Gaia Archive — Data Release 3
Measurement Uncertainties & Competing Solutions: M67 is the best-calibrated old open cluster in astrophysics: Kepler K2 asteroseismology, detached eclipsing binaries, white-dwarf cooling, and Gaia DR3 parallaxes (855 ± 12 pc) converge on an age of 4.0 ± 0.2 Gyr.

J2000 Equatorial Sky Chart & Culmination Altitude

The chart below plots King Cobra Cluster (Messier 67 / NGC 2682) at RA 08h 51m 18.00s, Dec +11° 48′ 00.0″ within Cancer, alongside peak meridian transit altitudes for 40°N and 30°S observers. Use the RA/Dec Coordinate Converter to compute exact culmination altitude for your latitude.

J2000 Equatorial Sky Position (Cancer) +90° 0° −90° 24h 12h RA 0h Peak Meridian Altitude 62° 40°N Lat 48° 30°S Lat RA: 08h 51m 18.00s Dec: +11° 48′ 00.0″ Epoch: J2000.0 · V = 6.1 mag First-party vector diagram derived from IAU / CDS SIMBAD / Gaia DR3 astrometry.

Astrophysical Context & Structure

Messier 67 (NGC 2682, the King Cobra or Golden Eye Cluster) is one of the oldest and most scientifically pivotal open clusters in the Milky Way, situated 2,790 light-years (855 ± 12 parsecs) away in southern Cancer. Discovered by Johann Gottfried Koehler before 1779 and independently cataloged by Charles Messier on April 6, 1780, M67 has survived for 4.0 ± 0.2 billion years—nearly ten times longer than typical open clusters—because its inclined Galactic orbit lifts it 1,500 light-years above the dusty midplane where destructive giant molecular clouds reside.

Because M67 has an iron abundance virtually identical to our Sun ([Fe/H] = 0.00 ± 0.02 dex) and an age close to the Sun's 4.6 billion years, it hosts more than 100 true 'solar twins' (such as YBP 1194, which shares the Sun's mass, temperature, and chemical fingerprint to within 1%). Its color-magnitude diagram is the foundational textbook benchmark for testing the morphological 'hook' at the main-sequence turnoff where 1.25-solar-mass stars develop convective hydrogen-burning cores.

M67 also contains ~30 prominent blue stragglers, over 200 cooling white dwarfs, and at least five confirmed exoplanets—including the hot Jupiter YBP 1194 b orbiting a solar twin and the giant planet S364 b orbiting an evolved red giant.

Practical Visual Observing Guide

Minimum Instrument7×50 or 10×50 binoculars
Recommended Magnification50×–120×
Best Evening SeasonLate Winter to Spring (February–May)
  • Located just 1.8° directly west of the 4.2-magnitude double star Acubens (α Cancri) in southern Cancer, about 8.5° south-southeast of the Beehive Cluster (M44).
  • In 10×50 binoculars M67 is an easy 6.1-magnitude oval patch anchored on its northeastern corner by a 7.8-magnitude foreground star (HD 75700).
  • Through a 100–200 mm telescope at 60×–120×, over 100 golden-yellow and orange subgiants and red-clump giants curve into the famous hooded 'King Cobra' shape.

Catalog Cross-Identifications & Aliases

Common Aliases: M67 · NGC 2682 · King Cobra Cluster · Golden Eye Cluster

Cross-Catalog Identifiers for King Cobra Cluster (Messier 67 / NGC 2682)
Catalog AuthorityIdentifier
MESSIERM 67
NGCNGC 2682
SIMBADM 67
WIKIDATAQ11483
Related Object · Cancer

Beehive Cluster (Messier 44 Praesepe)

Coordinates, Gaia DR3 distance (186.2 pc), magnitude 3.1, exoplanet hosts, and observing guide for the Beehive Cluster (M44 / NGC 2632).

Related Object · Taurus

Hyades (Melotte 25 Nearest Cluster)

Coordinates, Gaia DR3 distance (47.0 pc), age 650 Myr, moving-group kinematics, and observing guide for the Hyades cluster in Taurus.

Reference Guide

Trigonometric Parallax, Parsecs & Gaia DR3

How trigonometric parallax (d_pc = 1 / p_arcsec), the distance modulus equation, Hipparcos, and Gaia DR3 microarcsecond astrometry measure cosmic distances.

Reference Guide

Apparent vs Absolute Magnitude Explained

Understand the logarithmic Pogson astronomical magnitude scale, apparent visual magnitude (m), absolute magnitude (M at 10 parsecs), and bolometric corrections.

Scientific Sources & Dataset Provenance

  • ESA Gaia Archive — Data Release 3 (DR3 (2022-06-13)): Gaia Collaboration, Vallenari, A., et al. 2023, A&A, 674, A1 (Gaia Data Release 3) — European Space Agency / Gaia DPAC
  • Revised New General Catalogue and Index Catalogue (RNGC/IC) (2024/2026 edition): Steinicke, W. 2010, Observing and Cataloguing Nebulae and Star Clusters (Cambridge Univ. Press); Verga, M. OpenNGC (CC-BY-SA 4.0 / data tables) — Wolfgang Steinicke / OpenNGC
  • SIMBAD Astronomical Database (CDS) (2026-10 release): Wenger, M., et al. 2000, A&AS, 143, 9 (The SIMBAD astronomical database) — Centre de Données astronomiques de Strasbourg