Great Barred Spiral Galaxy (NGC 1365 / VV 825)
J2000 coordinates, HST/JWST Cepheid distance (59.7 Mly), magnitude 9.56, Z-shaped barred spiral, spinning black hole, and NGC 1365 observing guide.
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 |
|---|---|---|---|---|---|
| Integrated visual magnitude (V) | 9.56 mag | ± 0.08 mag | Wide-field integrated CCD aperture photometry | definitive | Revised New General Catalogue and Index Catalogue (RNGC/IC) |
| Distance in light-years | 59700000 ly | ± 1900000 ly | HST & JWST Cepheid period-luminosity relation + TRGB (18.3 ± 0.6 Mpc) | definitive | SH0ES Local Distance Ladder Hubble Constant |
| Apparent major axis | 11.2 arcmin | ± 0.4 arcmin | Optical 25 mag/arcsec² isophotal dimensions (11.2′ × 6.2′) | definitive | Revised New General Catalogue and Index Catalogue (RNGC/IC) |
| Heliocentric recession velocity | 1636 km/s | ± 4 km/s | H I 21-cm and ALMA CO molecular rotation spectroscopy | definitive | SIMBAD Astronomical Database (CDS) |
J2000 Equatorial Sky Chart & Culmination Altitude
The chart below plots Great Barred Spiral (NGC 1365 in Fornax) at RA 03h 33m 36.08s, Dec -36° 08′ 26.3″ within Fornax, 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
Discovered by James Dunlop on September 24, 1826, from Australia, the Great Barred Spiral Galaxy (NGC 1365) is widely considered the single most spectacular barred spiral galaxy in the visible universe. Residing 59.7 million light-years away in the Fornax Galaxy Cluster, NGC 1365 is a true supergiant spiral: its sweeping Z-shaped pair of outer spiral arms spans more than 200,000 light-years from tip to tip—roughly twice the diameter of the Milky Way—while its massive central stellar bar alone stretches nearly 90,000 light-years across.
High-resolution infrared imaging from the James Webb Space Telescope (PHANGS-JWST survey) reveals that NGC 1365 possesses a second, smaller nuclear bar nested inside its giant primary bar. Together, these twin bars act as a gravitational funnel, driving supersonic dust lanes and molecular clouds inward at hundreds of kilometers per second to ignite a fierce circumnuclear starburst ring and feed an active Seyfert 1.8 nucleus. Four supernovae have been recorded in NGC 1365: SN 1957C, 1983V, 2001du, and the bright Type Ia calibrator SN 2012fr.
In 2013 NASA's NuSTAR hard-X-ray telescope and ESA's XMM-Newton observatory used NGC 1365 to achieve the first direct measurement of a supermassive black hole's spin rate: by analyzing relativistically broadened iron K-alpha X-ray fluorescence lines reflected off the inner edge of the accretion disk, astronomers proved that NGC 1365's 2-million-solar-mass central black hole is spinning at more than 84% of the maximum relativistic Kerr limit allowed by general relativity.
Practical Visual Observing Guide
- Located on the southwestern side of the main Fornax Galaxy Cluster core, about 1.4° southwest of central elliptical NGC 1399.
- At declination −36° 08′, NGC 1365 rises 15°–25° above the southern horizon from mid-northern latitudes in late autumn and passes nearly overhead from the Southern Hemisphere.
- In a 150–250 mm (6–10 inch) telescope at 80×–140× under dark skies, NGC 1365 is one of the very few galaxies where visual observers can immediately trace a bright, 3′-long straight central bar with two dramatic, sharp-angled spiral arms hooking off opposite ends in a cosmic 'Z' shape!
Catalog Cross-Identifications & Aliases
Common Aliases: NGC 1365 · Great Barred Spiral Galaxy · PGC 13179 · ESO 358-G 017
| Catalog Authority | Identifier |
|---|---|
| NGC | NGC 1365 |
| SIMBAD | NGC 1365 |
| WIKIDATA | Q502006 |
Related Objects, Comparisons & Guides
Southern Pinwheel (Messier 83 / NGC 5236)
J2000 coordinates, Cepheid/TRGB distance (15.2 Mly), magnitude 7.54, barred spiral starburst core, six supernovae, and observing guide for Messier 83.
Messier 95 (NGC 3351 Theta-Shaped Spiral)
J2000 coordinates, HST Cepheid distance (32.6 Mly), magnitude 9.73, textbook SB(r)b bar and ring, circumnuclear knots, and observing guide for Messier 95.
Vacuum Cleaner Galaxy (M109 / NGC 3992)
J2000 coordinates, Tully-Fisher distance (67.2 Mly), magnitude 9.80, grand SB(rs)bc barred spiral, Phecda glare tips, and observing guide for M109.
Measurement Uncertainty & Optics in Astronomy
How random vs systematic errors, asymmetric error bars, model dependencies, and optical aperture/exit-pupil limits shape astronomical measurements.
Surface Brightness & Extended Objects Guide
Why surface brightness (mag/arcsec²) governs nebula and galaxy visibility more than integrated magnitude, and how exit pupil controls eyepiece contrast.
Scientific Sources & Dataset Provenance
- 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
- SH0ES Local Distance Ladder Hubble Constant (2022 Baseline Cepheid + SN Ia): Riess, A. G., et al. 2022, ApJL, 934, L7 (A Comprehensive Measurement of the Local Value of the Hubble Constant) — SH0ES Collaboration (HST / JWST)
- 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