What type of supernova is SN1964A and what kind of star exploded?
Astrophysics & Progenitor
SN1964A is classified as a Type II supernova, consistent with core collapse of a massive star that retained hydrogen in its outer envelope. Typical progenitor mass ranges quoted for the class are model expectations, not a measured mass for this star.
What was the progenitor star doing in the millions of years leading up to SN1964A?
Astrophysics & Progenitor
The specific progenitor of SN1964A has not been observed. Events of this spectroscopic class are generally associated with massive-star core collapse after successive nuclear burning stages (hydrogen → helium → carbon → neon → oxygen → silicon → iron). Typical lifetimes of such progenitors are tens of millions of years, but that is a class expectation—not a measured age or evolutionary track for this star. No pre-explosion imaging identification is cited in the available record for SN1964A.
How far away is SN1964A from Earth and how old is the light reaching us?
Cosmic Distance & Time
SN1964A has a luminosity distance of approximately 58.7 Million Light-Years (redshift z = 0.00387, d_L = 18). Under a flat ΛCDM cosmology (H₀≈70 km/s/Mpc, Ωₘ≈0.3), the corresponding lookback time is ≈54 Myr — when the light set out 53.9 million years ago during the early Cenozoic era, following the extinction of the non-avian dinosaurs. Luminosity distance is larger than the light-travel distance because cosmic expansion stretches the path; the two must not be equated.
What does the cosmological redshift of SN1964A tell us about the expansion of space?
Cosmic Distance & Time
SN1964A exhibits a measured spectroscopic redshift of z = 0.0039. The cockpit reports a user-facing recession velocity of 1,158.0 km/s, computed as the redshift Doppler-equivalent v = c·((1+z)²−1)/((1+z)²+1). Cosmological redshift is not generally equivalent to special-relativistic motion through space; this number is a convenient velocity label for z, not a measured peculiar velocity and not supernova ejecta speed. Bare c·z (≈1,160 km/s) is a different low-z approximation and is not mixed here.
How bright did SN1964A become at its peak, and how many Suns does that equal?
Explosion Energetics
At peak brightness, SN1964A achieved an apparent magnitude of 17 around 1964/02/03. Corrected for cosmic distance and foreground interstellar dust, its intrinsic absolute magnitude was -14.3. At this peak, the exploding star radiated with the incandescent brilliance of approximately 44.9 million Suns combined, briefly outshining the cumulative starlight of entire dwarf galaxies!
How much total energy was released by SN1964A, and where did that energy go?
Explosion Energetics
Core-collapse events of this broad class are often discussed with a ~10⁵³ erg gravitational binding energy of which ~99% may escape as neutrinos—again a class scale, not a measured budget for SN1964A.
How fast are the supernova ejecta and shockwave of SN1964A expanding through space?
Explosion Energetics
Spectroscopic line blueshifts imply an ejecta velocity of approximately 1,158 km/s (~0.4% of c) for SN1964A. This is distinct from cosmological recession velocity inferred from redshift.
What powers the prolonged glow of SN1964A weeks and months after detonation?
Radioactive Engine
Classified core-collapse light curves are often sustained after peak by radioactive ⁵⁶Ni → ⁵⁶Co → ⁵⁶Fe decay, with typical nickel yields of order 0.05–0.15 solar masses—again a class scale, not a measured yield for SN1964A. Shock-breakout heating may dominate the earliest optical flash; without a published bolometric fit, neither nickel mass nor the dominant power source is established for this event.
What chemical elements did SN1964A create and disperse into the universe?
Nucleosynthesis & Elements
Events of SN1964A's broad spectroscopic class are discussed in galactic chemical evolution as sources of oxygen-group and intermediate-mass elements (and, for some channels, iron-peak material). No measured elemental yields are published for SN1964A.
Did SN1964A leave behind a black hole, a neutron star, or nothing at all?
Cosmic Remnant
A core-collapse explosion associated with SN1964A's class forges an ultra-dense compact stellar remnant at the center of the detonation. If the progenitor had an initial mass under ~20 solar masses, it left behind a neutron star (pulsar)—packing the mass of our entire Sun into a city-sized sphere barely 20 kilometers wide, spinning dozens or hundreds of times per second. If the progenitor exceeded ~25–30 solar masses, gravity overcame neutron degeneracy pressure, creating a permanent stellar-mass black hole.
What will SN1964A's explosion site look like in 1,000 to 10,000 years?
Cosmic Remnant
Supernova remnants in general evolve through free-expansion, Sedov–Taylor, and radiative phases over centuries to millennia, sometimes becoming bright X-ray shells and occasionally compressing nearby molecular clouds. These are standard remnant-evolution models, not forecasts measured for SN1964A. Whether this site will trigger star formation, reach particular X-ray temperatures, or match Cassiopeia A depends on local density and magnetic field—none of which are constrained by the data shown here.
In which galaxy did SN1964A explode, and where is it located relative to the galactic center?
Galactic Environment
SN1964A is associated with cataloged host NGC 3631 at an angular/physical offset of 119.30″ (9.85 kpc) from the reported galactic center. That offset places the transient in the host's projected light distribution; it does not by itself prove which stellar population produced the progenitor.
Where is SN1964A located in the night sky and which constellation is it in?
Sky Coordinates
In the celestial sphere, SN1964A is located at Right Ascension 11:20:54.1 and Declination +53:11:40, situated in the constellation Ursa Major (The Great Bear). Because its declination is +53:11:40, it is primarily placed in the Northern celestial hemisphere.
How much Milky Way interstellar dust obscures our view of SN1964A?
Interstellar Dust
Along this line of sight, the catalog records a Milky Way foreground color excess of E(B−V) = 0.0142 mag (source: published extinction estimate), corresponding to roughly A_V ≈ 0.04 mag for R_V = 3.1. Band-specific corrections (e.g. A_r) differ from A_V and should be applied when available. Map-based values (IRSA / Schlafly & Finkbeiner 2011) must not be claimed unless that map was actually queried.
Across which photometric filter bands was SN1964A monitored?
Astronomical Observations
No calibrated photometry is published for SN1964A. Without multi-epoch flux measurements, neither a light curve nor a peak magnitude can be established. Follow-up imaging from survey alert streams would be required to map its brightness evolution.
What did astronomical spectroscopy reveal about SN1964A's chemical makeup?
Astronomical Observations
No spectrum has been published for SN1964A. Without spectroscopy, its chemical composition, expansion velocity, and physical classification cannot be established. Classification spectra from follow-up observatories would be required to identify diagnostic absorption and emission lines.
Who discovered SN1964A and how was it first detected?
Discovery & History
SN1964A was officially reported on 1964/02/04 by Wild. Discoveries are typically flagged by high-cadence robotic survey telescopes (such as ATLAS, ZTF, Pan-STARRS, ASAS-SN, or Gaia) and worldwide amateur astronomers scanning the night sky, followed by rapid spectroscopic classification by international observatories.
How many scientific publications and observatories have contributed data to SN1964A?
Scientific Research
Data for SN1964A are compiled from international astronomical notices, the IAU Transient Name Server (TNS), and peer-reviewed astrophysical journals.
How does SN1964A contribute to measuring the Hubble Constant and the scale of the cosmos?
Cosmology & Distance Ladder
As a core-collapse supernova, SN1964A provides independent cosmological distance calibrations via the Expanding Photosphere Method (EPM) and the Standard Candle Method for Type II supernovae (SCM-II). By correlating the physical expansion speed of the photosphere (measured via spectroscopic Doppler shifts) with its photometric color temperature, astronomers determine direct geometric distances independent of secondary distance ladders.
Could gravitational waves or neutrinos from SN1964A be detected on Earth?
Multi-Messenger Astronomy
Core-collapse supernovae like SN1964A are premier targets for multi-messenger astrophysics! During the collapse of the iron core, an intense burst of 10⁵⁸ neutrinos escaped into space hours before the shock broke out through the stellar surface (as famously seen in SN 1987A). Furthermore, violent core asymmetries and non-axisymmetric core bounce can emit high-frequency gravitational waves detectable by advanced interferometers (LIGO, Virgo, KAGRA) for events within the Milky Way and Local Group.
How does SN1964A compare to famous historical supernovae like SN 1987A or the Crab Supernova?
Historical Comparison
Compared to historical landmarks like SN 1987A in the Large Magellanic Cloud (168,000 light-years away, naked-eye peak m = 2.9) or the Crab Supernova of 1054 (6,500 light-years away), SN1964A occurred at a distance of 58.7 Million Light-Years. While historical naked-eye supernovae occurred within our Milky Way or its immediate satellites, modern discoveries like SN1964A allow astrophysicists to probe diverse galactic environments, metallicities, and stellar populations across the broader universe.
Can I see SN1964A tonight with a backyard telescope or binoculars?
Backyard Observation
Unknown — no measured brightness. SN1964A was discovered 22915 days ago (1964/02/04), but no calibrated photometry is published for it, so its current apparent magnitude cannot be stated. Without a magnitude there is no basis for a telescope-aperture recommendation. Use the coordinates and airmass chart above to plan a follow-up observation and report what you measure.
Does the radiation or shockwave from SN1964A pose any threat to Earth?
Planetary Safety
No, Earth is in zero danger. Supernovae are violent events emitting powerful gamma rays, X-rays, and cosmic rays; however, the astrophysical 'lethal kill zone' for our planet's protective ozone layer is estimated at 50 to 100 light-years. At a distance of 58.7 Million Light-Years, the inverse-square law dilutes the radiation by quintillions of times, making SN1964A completely harmless to our biosphere and purely a fascinating spectacle for human exploration.
