Supernova 1987A Remnant (SN 1987A in Large Magellanic Cloud)
Coordinates, LMC distance (49.6 kpc / 161,800 ly), equatorial pearl necklace shock, JWST central neutron star detection, and SN 1987A data.
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.
| Parameter | Value | Uncertainty | Method & Epoch | Quality Status | Source Archive |
|---|---|---|---|---|---|
| Current shock-ring integrated visual magnitude | 16.2 mag | ± 0.3 mag | HST WFC3 optical ring + ejecta photometry (May 1987 peak was V = 2.9) | definitive | SIMBAD Astronomical Database (CDS) |
| Heliocentric distance | 161800 ly | ± 2000 ly | Light-echo ring geometry (Panagia 1991) + LMC eclipsing binaries (49.59 ± 0.63 kpc) (J2016.0) | definitive | SIMBAD Astronomical Database (CDS) |
| Outer hourglass ring span | 0.09 arcmin | ± 0.01 arcmin | HST/JWST outer bipolar loops (5.2″ × 3.5″; bright inner ring is 1.66″ × 1.21″) | definitive | SIMBAD Astronomical Database (CDS) |
J2000 Equatorial Sky Chart & Culmination Altitude
The chart below plots SN 1987A Remnant (LMC Triple-Ring Supernova) at RA 05h 35m 27.97s, Dec -69° 16′ 11.1″ within Dorado, 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.
Astrophysical Context & Structure
Supernova 1987A (SN 1987A) is the closest and brightest supernova observed from Earth since Kepler's Supernova of 1604, discovered on the night of February 23–24, 1987, by Ian Shelton, Oscar Duhalde, and Albert Jones on the southwestern outskirts of the Tarantula Nebula (NGC 2070) in the Large Magellanic Cloud, 161,800 light-years (49.59 ± 0.63 kiloparsecs) away in Dorado. Three hours before the optical shock broke through the stellar surface, underground Cherenkov detectors at Kamiokande II, IMB, and Baksan recorded 25 electron antineutrinos emitted during the 10-second collapse of the star's iron core—launching the era of multi-messenger extrasolar neutrino astronomy and confirming that the progenitor was a 20-solar-mass B3 Ia blue supergiant (Sanduleak −69° 202) formed by a binary merger ~20,000 years before explosion.
Beginning in 1994, the Hubble Space Telescope watched in real time as SN 1987A transitioned from a fading supernova into a newborn supernova remnant: the 10,000-km/s blast wave slammed into a 1.3-light-year equatorial ring of gas ejected 20,000 years earlier, lighting up dozens of shock-heated 'hot spots' like a cosmic necklace of glowing pearls flanked by two larger outer hourglass rings.
For 37 years, the newly formed neutron star predicted by the 1987 neutrino burst remained hidden behind a cold (~20 K), 0.5-solar-mass cloud of freshly condensed titanium-, iron-, and silicon-rich dust in the core. Finally, in February 2024, integral-field spectroscopy with the James Webb Space Telescope's NIRSpec and MIRI instruments penetrated that central dust shroud and detected narrow emission lines of singly and quintuply ionized argon ([Ar II] and [Ar VI]) and sulfur at the exact explosion center—proving that a hot cooling neutron star or pulsar wind nebula is ionizing the inner ejecta from within.
Practical Visual Observing Guide
- Located just 20 arcminutes southwest of the Tarantula Nebula (NGC 2070) in the Large Magellanic Cloud at RA 05h 35m 28.0s, Dec −69°16′11″ (Southern Hemisphere).
- While SN 1987A shone at naked-eye magnitude 2.9 in May 1987, its 1.7-arcsecond shocked ring and two closely flanking 15th-magnitude companion stars (Star 2 and Star 3, separated by 2.9″ and 1.6″) now have a combined visual magnitude near 14.5–16.2.
- Observers with 300–500 mm+ apertures at 300×+ under steady southern skies can pinpoint the exact three-star unresolved knot inside the outer Honeycomb/30 Doradus H II filaments.
Catalog Cross-Identifications & Aliases
Common Aliases: SN 1987A · Supernova 1987A Remnant · Sanduleak -69 202
| Catalog Authority | Identifier |
|---|---|
| SIMBAD | SN 1987A |
| WIKIDATA | Q182154 |
Related Objects, Comparisons & Guides
Tarantula Nebula (NGC 2070 / 30 Doradus)
Coordinates, LMC distance (49.6 kpc / 161,800 ly), R136 super star cluster (R136a1), and observing guide for the Tarantula Nebula in Dorado.
Cassiopeia A (3C 461 Young Supernova Remnant)
Coordinates, kinematic distance (3.4 kpc), JWST/Chandra ejecta knots, and high-aperture observing guide for Cassiopeia A (3C 461).
Crab Nebula (Messier 1 Supernova Remnant)
Coordinates, Gaia DR3 distance (1.96 kpc), SN 1054 history, pulsar wind physics, and observing guide for the Crab Nebula (M1) in Taurus.
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.
Measurement Uncertainty & Optics in Astronomy
How random vs systematic errors, asymmetric error bars, model dependencies, and optical aperture/exit-pupil limits shape astronomical measurements.
Scientific Sources & Dataset Provenance
- 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
- 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