High-magnification deep optical view into SN1961H's host environment. Pan and scroll to explore the cosmic neighborhood where this star exploded.
★ Benchmark Astrophysical Landmark
SN1961H is recognized as one of the definitive benchmark supernovae in modern astrophysics. Due to its exceptional peak luminosity, favorable host galaxy orientation, and rapid multi-messenger follow-up, it was extensively observed across the electromagnetic spectrum by premier facilities—including space telescopes (HST, JWST, Swift) and global ground-based spectroscopic networks. It provides foundational empirical constraints for stellar progenitor models, ejecta dynamics, and cosmological distance calibrations.
⚡ Quick Observer Facts & Telemetry
IAU Transients DBA Type Ia Thermonuclear Explosion
On 1961/05/02, astronomers scanning the heavens flagged a sudden, violent pinpoint of light that had flared into visibility. Designated SN1961H, it represents a catastrophic stellar explosion classified as a Type Ia supernova.
SN1961H is spectroscopically classified as Type Ia, consistent with a thermonuclear white-dwarf explosion in NGC 4564. Competing progenitor channels (single-degenerate accretion, double-degenerate merger, sub-Chandrasekhar detonations) remain open; an individual accretion history toward the Chandrasekhar mass is not established for this event.
A Message Across Deep Cosmic Time
SN1961H has a luminosity distance of approximately 47.6 Million Light-Years
(redshift z = 0.003809).
That figure is not the light-travel time: under flat ΛCDM the lookback time is ≈53 Myr, when the light set out 53.1 million years ago during the early Cenozoic era, following the extinction of the non-avian dinosaurs.
Luminosity distance incorporates cosmic expansion and exceeds the light-travel distance. The two quantities must be reported separately.
Incandescence of 7.9 billion Suns
At the height of the outburst around 1961/05/08, SN1961H surged to a peak apparent magnitude of 10.9 and an intrinsic absolute magnitude of -19.92. At that instant, this single dying star radiated with the collective power of approximately 7.9 billion Suns combined, outshining whole dwarf galaxies.
The total energy released by the cataclysm was on the order of 10⁵¹ to 10⁵³ ergs. Virtually all of this was deposited into the kinetic shockwave and radioactive nucleosynthesis.
The Radioactive Furnace: Why Supernovae Glow for Months
After peak, many supernovae are powered by the radioactive chain ⁵⁶Ni → ⁵⁶Co → ⁵⁶Fe. That is the standard model for Type Ia light curves; an object-specific nickel mass for SN1961H is not published here.
Nickel-56 decays to Cobalt-56 (half-life ≈6.1 days), then to stable Iron-56 (half-life ≈77.2 days), heating the ejecta from within. Typical class yields must not be quoted as measured values for this event.
Cosmic Kiln: Seeding the Elements of Life
Supernovae enrich galaxies with heavy elements. Events of SN1961H's class are associated with iron-peak and intermediate-mass products (Ni/Fe, Si, S, Ca) in galactic chemical-evolution models. No measured elemental yields are published for SN1961H.
As Carl Sagan observed, "We are made of star-stuff" — a statement about nucleosynthesis in general, not a claim that atoms from this specific remnant are identified in the Solar System.
Galactic Setting in Coma Berenices
SN1961H is associated with cataloged host NGC 4564
, at an offset of 5.36″ (0.36 kpc) from the reported galactic center.
In our terrestrial sky, it resides in the constellation Coma Berenices (Berenice's Hair) at Right Ascension 12:36:27.27
and Declination +11:26:24.6.
The Scientific Surveillance Campaign
Following its discovery by Romano, observatories worldwide swung their lenses toward SN1961H. In the Open Supernova Catalog, SN1961H is documented across 0 photometric measurements and 0 spectroscopic epochs. These multi-wavelength observations allow astrophysicists to model the expanding photosphere, measure shock velocities, and probe circumstellar interactions.
Stargazer's Field Guide: Can You See It Tonight?
Can I see it tonight? Unknown — no measured brightness.
Discovered 65.5 years ago (1961/05/02). No reliable current brightness estimate — no photometry has been published.
Planetary Safety Note: Even though SN1961H was a titanic explosion, our planet sits safely outside the lethal 50–100 light-year kill zone. At a distance of 47.6 Million Light-Years, the blast poses zero physical hazard to Earth's biosphere.
Cataloged transients closest to SN1961H in discovery time, spatial sky neighborhood, and cosmological redshift:
❓ Frequently Asked Questions About SN1961H
What type of supernova is SN1961H and what kind of star exploded? Astrophysics & Progenitor
What was the progenitor star doing in the millions of years leading up to SN1961H? Astrophysics & Progenitor
How far away is SN1961H from Earth and how old is the light reaching us? Cosmic Distance & Time
What does the cosmological redshift of SN1961H tell us about the expansion of space? Cosmic Distance & Time
How bright did SN1961H become at its peak, and how many Suns does that equal? Explosion Energetics
How much total energy was released by SN1961H, and where did that energy go? Explosion Energetics
How fast are the supernova ejecta and shockwave of SN1961H expanding through space? Explosion Energetics
What powers the prolonged glow of SN1961H weeks and months after detonation? Radioactive Engine
What chemical elements did SN1961H create and disperse into the universe? Nucleosynthesis & Elements
Did SN1961H leave behind a black hole, a neutron star, or nothing at all? Cosmic Remnant
What will SN1961H's explosion site look like in 1,000 to 10,000 years? Cosmic Remnant
In which galaxy did SN1961H explode, and where is it located relative to the galactic center? Galactic Environment
Where is SN1961H located in the night sky and which constellation is it in? Sky Coordinates
How much Milky Way interstellar dust obscures our view of SN1961H? Interstellar Dust
Across which photometric filter bands was SN1961H monitored? Astronomical Observations
What did astronomical spectroscopy reveal about SN1961H's chemical makeup? Astronomical Observations
Who discovered SN1961H and how was it first detected? Discovery & History
How many scientific publications and observatories have contributed data to SN1961H? Scientific Research
What other names and survey identifiers exist for SN1961H? Cross-Identifications
AAVSO 1231+12. These cross-matched identifiers allow astronomers to cross-reference observations across the Zwicky Transient Facility (ZTF), the Asteroid Terrestrial-impact Last Alert System (ATLAS), Pan-STARRS, Gaia Photometric Science Alerts, and the IAU Transient Name Server (TNS).