Host Optical Cutout
0.26″/pix
Pan-STARRS1 DR1 Optical (0.25″/pix)
Core Parameters
| R.A. (J2000) | 09:55:24.7747 (148.85323°) |
|---|---|
| Dec. (J2000) | +69:01:13.702 (69.02047°) |
| Spectral Type | IIb |
| Redshift (z) | -0.000113 |
| Recession Velocity | -35 km/s (redshift Doppler-equivalent) |
| Luminosity Distance | 2.9 Mpc |
| Peak Apparent Mag | 9.91 brightest multi-epoch detection (1993/03/30) |
| Peak Absolute Mag | -17.4 |
| MW Dust E(B-V) | 0.069 mag derived from galactic coordinates (coordinate model), not a dust-map measurement |
| Host Galaxy | NGC 3031 |
| Host Offset | 167.2 |
| Observations | 1838 detections, 100 spectra |
Interactive Sky Field (Aladin) ✨ DSS2 Optical (China-VO mirror)
🎯 09:55:24.7747 +69:01:13.702
FOV: 0.15°
● SN1993J (IIb)
Coordinate Pointing & Airmass
Discovered 33.6 years ago (1993/03/28). Cataloged peak 1993/03/30 (12271d ago; rest-frame phase +12271.0d). Cataloged/observed peak: m = 9.91 on 1993/03/30. Latest observed: m = 17.09 on 2014/06/12 (MJD 56820.0). No reliable current brightness estimate — no event-specific brightness fit with documented uncertainty is published for this object. Class-average decay templates are not used as object-specific predictions. Latest observed magnitude: m = 17.09 on 2014/06/12 (MJD 56820.0). Current brightness trend is unknown (last observation 2014/06/12 (MJD 56820.0); same-band recent pair unavailable or stale). Use the window below to plan observations tonight.
Multi-Band Light Curve
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Calibrated Spectra Viewer
🌌 Cosmic Neighbors & Contemporaries
105,768+ transients indexed
Cataloged transients closest to SN1993J in discovery time, spatial sky neighborhood, and cosmological redshift:
⏱️ Closest in Time
SN1993K
Exploded same day
Type II?
1993/03/28 · Mag 14.5
GRB 930326A
2d before
Type LGRB
1993/03/26
SN1993ak
+2d after
Type Transient
1993/03/30 · Mag 16.5
Literature & Data Provenance
| ID | Source | Reference | NASA ADS Bibcode |
|---|---|---|---|
| [1] | 2019MNRAS.482.1545S | Shivvers et al. (2019) | 2019MNRAS.482.1545S |
| [2] | 2016ApJ...833..231T | Tinyanont et al. (2016) | 2016ApJ...833..231T |
| [3] | 2015A&A...573A..12J | Jerkstrand et al. (2015) | 2015A&A...573A..12J |
| [4] | 2014AJ....147...99M | Modjaz et al. (2014) | 2014AJ....147...99M |
| [5] | 2012A&A...538A.120L | Lennarz, Altmann, & Wiebusch (2012) | 2012A&A...538A.120L |
| [6] | 2011ApJ...737..103S | Schlafly & Finkbeiner (2011) | 2011ApJ...737..103S |
| [7] | 2007ApJ...668..924B | Bartel et al. (2007) | 2007ApJ...668..924B |
| [8] | 2004AJ....127.3587F | Fey et al. (2004) | 2004AJ....127.3587F |
| [9] | 2000AJ....120.1499M | Matheson et al. (2000) | 2000AJ....120.1499M |
| [10] | 1998ApJ...500...51W | Weiler et al. (1998) | 1998ApJ...500...51W |
| [11] | 1996AJ....112..732R | Richmond et al. (1996) | 1996AJ....112..732R |
| [12] | 1995A&AS..110..513B | Barbon et al. (1995) | 1995A&AS..110..513B |
| [13] | 1995PAZh...21..670M | Metlova et al. (1995) | 1995PAZh...21..670M |
| [14] | 1995ApJ...446..167C | Clocchiatti et al. (1995) | 1995ApJ...446..167C |
| [15] | 1995ApJ...441..170B | Baron et al. (1995) | 1995ApJ...441..170B |
| [16] | 1994AJ....107.1022R | Richmond et al. (1994) | 1994AJ....107.1022R |
| [17] | 1994supe.conf...27L | 1994supe.conf...27L | |
| [18] | 1994AJ....107.1453B | Benson et al. (1994) | 1994AJ....107.1453B |
| [19] | 1994ApJ...426..334B | Baron, Hauschildt, & Branch (1994) | 1994ApJ...426..334B |
| [20] | 1993PASJ...45L..59V | van Driel et al. (1993) | 1993PASJ...45L..59V |
| [21] | 1993PASJ...45L..63O | Okyudo et al. (1993) | 1993PASJ...45L..63O |
| [22] | 1993IAUC.5796....1M | Mikuz, Dintinjana, & Zwitter (1993) | 1993IAUC.5796....1M |
| [23] | 1993IAUC.5782....1Z | Zhou (1993) | 1993IAUC.5782....1Z |
| [24] | IAUC 5731 | Ripero et al. (1993) | 1993IAUC.5731....1R |
| [25] | 1993PhDT........95S | Schmidt (1993) | 1993PhDT........95S |
| [26] | 1993Natur.364..600S | Schmidt et al. (1993) | 1993Natur.364..600S |
| [27] | 1993ApJ...416L..21B | Baron et al. (1993) | 1993ApJ...416L..21B |
| [28] | Transient Name Server | — | |
| [29] | CfA Supernova Archive | — | |
| [30] | Latest Supernovae | — | |
| [31] | SUSPECT | — | |
| [32] | Sternberg Astronomical Institute Supernova Light Curve Catalogue | — | |
| [33] | The Open Supernova Catalog | Guillochon et al. (2017) | 2017ApJ...835...64G |
| [34] | UCB Filippenko Group's Supernova Database (SNDB) | Silverman et al. (2012) | 2012MNRAS.425.1789S |
| [35] | WISeREP | Yaron & Gal-Yam (2012) | 2012PASP..124..668Y |
| [36] | SIMBAD astronomical database | Wenger et al. (2000) | 2000A&AS..143....9W |
| [37] | NED-D v13.1.0 | Helou et al. (1991) | 1991ASSL..171...89H |
| [38] | Asiago Supernova Catalogue | Barbon, Cappellaro, & Turatto (1989) | 1989A&AS...81..421B |
❓ Frequently Asked Questions About SN1993J
Scientific & observational Q&As indexed from astronomical databases & the Open Supernova Catalog
What type of supernova is SN1993J and what kind of star exploded? Astrophysics & Progenitor
SN1993J is a stripped-envelope supernova (Type IIb), consistent with core collapse after loss of the outer hydrogen (and for Ic, helium) envelope. The specific progenitor channel for this object is not uniquely determined by the spectral type alone.
What was the progenitor star doing in the millions of years leading up to SN1993J? Astrophysics & Progenitor
The specific progenitor of SN1993J 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 SN1993J.
How far away is SN1993J from Earth and how old is the light reaching us? Cosmic Distance & Time
SN1993J has a luminosity distance of approximately 9.5 Million Light-Years (redshift z = -0.000113, d_L = 2.9 Mpc). A lookback time is not computed here without a usable redshift; do not interpret the luminosity-distance light-year figure as travel time.
What does the cosmological redshift of SN1993J tell us about the expansion of space? Cosmic Distance & Time
No spectroscopic redshift has been measured for SN1993J. Without a published z, its place in the Hubble flow, recession velocity, and lookback time cannot be stated. A redshift requires a spectrum (or a well-calibrated photometric redshift from multi-band imaging). Check the sources below for follow-up spectroscopy.
How bright did SN1993J become at its peak, and how many Suns does that equal? Explosion Energetics
At peak brightness, SN1993J achieved an apparent magnitude of 9.91 around 1993/03/30. Corrected for cosmic distance and foreground interstellar dust, its intrinsic absolute magnitude was -17.4. At this peak, the exploding star radiated with the incandescent brilliance of approximately 779.8 million Suns combined, briefly outshining the cumulative starlight of entire dwarf galaxies!
How much total energy was released by SN1993J, 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 SN1993J.
How fast are the supernova ejecta and shockwave of SN1993J expanding through space? Explosion Energetics
No ejecta velocity is measured for SN1993J. Blast-wave speed is obtained from Doppler shifts of spectral absorption features (e.g. Si II λ6355 for Type Ia), not from cosmological redshift. Any recession velocity derived from z describes Hubble flow, not the explosion debris. Type IIb events typically show ejecta speeds of order ~12,500 km/s near maximum, but that class scale is not a measurement of SN1993J.
What powers the prolonged glow of SN1993J 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 SN1993J. 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 SN1993J create and disperse into the universe? Nucleosynthesis & Elements
Events of SN1993J'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 SN1993J.
Did SN1993J leave behind a black hole, a neutron star, or nothing at all? Cosmic Remnant
A core-collapse explosion associated with SN1993J'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 SN1993J'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 SN1993J. 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 SN1993J explode, and where is it located relative to the galactic center? Galactic Environment
SN1993J is associated with cataloged host NGC 3031 at an angular/physical offset of 167.2 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 SN1993J located in the night sky and which constellation is it in? Sky Coordinates
In the celestial sphere, SN1993J is located at Right Ascension 09:55:24.7747 and Declination +69:01:13.702, situated in the constellation Ursa Major (The Great Bear). Because its declination is +69:01:13.702, it is primarily placed in the Northern celestial hemisphere.
How much Milky Way interstellar dust obscures our view of SN1993J? Interstellar Dust
Along this line of sight, the catalog records a Milky Way foreground color excess of E(B−V) = 0.0690 mag (source: 6,33), corresponding to roughly A_V ≈ 0.21 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 SN1993J monitored? Astronomical Observations
SN1993J was tracked across 1838 photometric observations across a baseline of 7744.0 days utilizing filter bands including
B, I, I1, I2, R, U, V. Data were captured by observatories and survey networks including Spitzer. Multi-color photometry tracks the temperature evolution of the fireball, verifying the rise time to peak and the rate of radioactive decline.What did astronomical spectroscopy reveal about SN1993J's chemical makeup? Astronomical Observations
Astronomers obtained 100 spectroscopic epochs for SN1993J from 3094.0 Å to 12000.0 Å. Optical spectroscopy provides the definitive physical fingerprint of the transient: P-Cygni line profiles reveal the expansion speed of the ejecta, while characteristic absorption features (such as hydrogen Balmer lines Hα/Hβ in Type II, or Si II λ6355 in Type Ia) identify the stellar composition and physical mechanism of the explosion.
Who discovered SN1993J and how was it first detected? Discovery & History
SN1993J was officially reported on 1993/03/28 by Garcia. 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 SN1993J? Scientific Research
SN1993J is documented across 38 scientific references and archival data sources in the Open Supernova Catalog. These include discovery circulars and research datasets from 2019MNRAS.482.1545S, 2016ApJ...833..231T, 2015A&A...573A..12J, 2014AJ....147...99M. All raw photometry and spectroscopy points are cross-indexed to their original bibliographic records for peer-reviewed verification.
What other names and survey identifiers exist for SN1993J? Cross-Identifications
Throughout global alert streams and survey databases, SN1993J has also been designated as:
EQ 0951+692, ICRF J095524.7+690113, IERS B0951+692, INTREF 395, PBC J0955.1+6904, RORF 0951+692, 2XMM J095524.7+690114, H18, P36, M81 XMM2. 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).How does SN1993J contribute to measuring the Hubble Constant and the scale of the cosmos? Cosmology & Distance Ladder
As a core-collapse supernova, SN1993J 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 SN1993J be detected on Earth? Multi-Messenger Astronomy
Core-collapse supernovae like SN1993J 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 SN1993J 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), SN1993J occurred at a distance of 9.5 Million Light-Years. While historical naked-eye supernovae occurred within our Milky Way or its immediate satellites, modern discoveries like SN1993J allow astrophysicists to probe diverse galactic environments, metallicities, and stellar populations across the broader universe.
Can I see SN1993J tonight with a backyard telescope or binoculars? Backyard Observation
Unknown — no measured brightness. SN1993J was discovered 12273 days ago (1993/03/28), 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 SN1993J 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 9.5 Million Light-Years, the inverse-square law dilutes the radiation by quintillions of times, making SN1993J completely harmless to our biosphere and purely a fascinating spectacle for human exploration.
Data sourced from IAU TNS, ALeRCE, WISeREP, and the Open Supernova Catalog.
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