Host Optical Cutout
0.26″/pix
DESI DR10 Optical (0.26″/pix)
Core Parameters
| R.A. (J2000) | 04:45:49.430 (71.45596°) |
|---|---|
| Dec. (J2000) | -59:14:42.56 (-59.24516°) |
| Spectral Type | Ib/c |
| Redshift (z) | 0.00444 |
| Recession Velocity | 1330 km/s (redshift Doppler-equivalent) |
| Luminosity Distance | 19.72 Mpc (~62.2 Million Light-Years, μ = 31.40) |
| Peak Apparent Mag | 14.17 brightest multi-epoch detection (2017/09/08) |
| Peak Absolute Mag | -17.3 |
| MW Dust E(B-V) | 0.0201 mag derived from galactic coordinates (coordinate model), not a dust-map measurement |
| Host Galaxy | NGC 1672 |
| Host Offset | — |
| Observations | 23 detections, 1 spectra |
Interactive Sky Field (Aladin) ✨ DSS2 Optical (China-VO mirror)
🎯 04:45:49.430 -59:14:42.56
FOV: 0.15°
● SN2017gax (Ib/c)
Coordinate Pointing & Airmass
Discovered 9.3 years ago (2017/08/14). Cataloged peak 2017/09/08 (3354d ago; rest-frame phase +3339.2d). Cataloged/observed peak: m = 14.17 on 2017/09/08. Latest observed: m = 18.27 on 2018/03/12 (MJD 58189.2). 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 = 18.27 on 2018/03/12 (MJD 58189.2). Current brightness trend is unknown (last observation 2018/03/12 (MJD 58189.2); same-band recent pair unavailable or stale). It is below the horizon right now; use the window below to find the next observable slot.
Multi-Band Light Curve
|
Calibrated Spectra Viewer
🌌 Cosmic Neighbors & Contemporaries
105,868+ transients indexed
Cataloged transients closest to SN2017gax in discovery time, spatial sky neighborhood, and cosmological redshift:
⏱️ Closest in Time
AT2017gdf
Exploded same day
Type Candidate
2017/08/14 · Mag 18.8
AT2017gmv
Exploded same day
Type Candidate
2017/08/14 · Mag 18.8
AT2017gfr
Exploded same day
Type Candidate
2017/08/14 · Mag 19.1
Literature & Data Provenance
| ID | Source | Reference | NASA ADS Bibcode |
|---|---|---|---|
| [1] | 2016A&A...594A..13P | Planck Collaboration et al. (2016) | 2016A&A...594A..13P |
| [2] | SOUSA | Brown et al. (2014) | 2014Ap&SS.354...89B |
| [3] | 2011ApJ...737..103S | Schlafly & Finkbeiner (2011) | 2011ApJ...737..103S |
| [4] | ATel 10638 | — | |
| [5] | Gaia Photometric Science Alerts | — | |
| [6] | Latest Supernovae | — | |
| [7] | The Open Supernova Catalog | Guillochon et al. (2017) | 2017ApJ...835...64G |
| [8] | WISeREP | Yaron & Gal-Yam (2012) | 2012PASP..124..668Y |
❓ Frequently Asked Questions About SN2017gax
Scientific & observational Q&As indexed from astronomical databases & the sne.space
What type of supernova is SN2017gax and what kind of star exploded? Astrophysics & Progenitor
SN2017gax is a stripped-envelope supernova (Type Ib/c), 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 SN2017gax? Astrophysics & Progenitor
The specific progenitor of SN2017gax 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 SN2017gax.
How far away is SN2017gax from Earth and how old is the light reaching us? Cosmic Distance & Time
SN2017gax has a luminosity distance of approximately 64.3 Million Light-Years (redshift z = 0.00444, d_L = 19.72 Mpc). Under a flat ΛCDM cosmology (H₀≈70 km/s/Mpc, Ωₘ≈0.3), the corresponding lookback time is ≈62 Myr — when the light set out 61.8 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 SN2017gax tell us about the expansion of space? Cosmic Distance & Time
SN2017gax exhibits a measured spectroscopic redshift of z = 0.0044. The cockpit reports a user-facing recession velocity of 1,328.1 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 (≈1,331 km/s) is a different low-z approximation and is not mixed here.
How bright did SN2017gax become at its peak, and how many Suns does that equal? Explosion Energetics
At peak brightness, SN2017gax achieved an apparent magnitude of 14.17 around 2017/09/08. Corrected for cosmic distance and foreground interstellar dust, its intrinsic absolute magnitude was -17.3. At this peak, the exploding star radiated with the incandescent brilliance of approximately 711.2 million Suns combined, briefly outshining the cumulative starlight of entire dwarf galaxies!
How much total energy was released by SN2017gax, 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 SN2017gax.
How fast are the supernova ejecta and shockwave of SN2017gax expanding through space? Explosion Energetics
Spectroscopic line blueshifts imply an ejecta velocity of approximately 1,330 km/s (~0.4% of c) for SN2017gax. This is distinct from cosmological recession velocity inferred from redshift.
What powers the prolonged glow of SN2017gax 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 SN2017gax. 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 SN2017gax create and disperse into the universe? Nucleosynthesis & Elements
Events of SN2017gax'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 SN2017gax.
Did SN2017gax leave behind a black hole, a neutron star, or nothing at all? Cosmic Remnant
A core-collapse explosion associated with SN2017gax'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 SN2017gax'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 SN2017gax. 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 SN2017gax explode, and where is it located relative to the galactic center? Galactic Environment
SN2017gax is cataloged with host galaxy NGC 1672. No secure nuclear offset is published in this record.
Where is SN2017gax located in the night sky and which constellation is it in? Sky Coordinates
In the celestial sphere, SN2017gax is located at Right Ascension 04:45:49.430 and Declination -59:14:42.56, situated in the constellation Dorado (The Swordfish / Dolphinfish). Because its declination is -59:14:42.56, it is favorably placed for Southern Hemisphere observatories.
How much Milky Way interstellar dust obscures our view of SN2017gax? Interstellar Dust
Along this line of sight, the catalog records a Milky Way foreground color excess of E(B−V) = 0.0201 mag (source: 3,7), corresponding to roughly A_V ≈ 0.06 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 SN2017gax monitored? Astronomical Observations
SN2017gax was tracked across 23 photometric observations across a baseline of 207.3 days utilizing filter bands including
B, G, U, UVM2, UVW1, UVW2, V. Data were captured by observatories and survey networks including GAIA, Swift. 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 SN2017gax's chemical makeup? Astronomical Observations
Astronomers obtained 1 spectroscopic epochs for SN2017gax from 3496.2 Å to 9400.4 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 SN2017gax and how was it first detected? Discovery & History
SN2017gax was officially reported on 2017/08/14 by DLT40. 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 SN2017gax? Scientific Research
SN2017gax is documented across 8 scientific references and archival data sources in the sne.space. These include discovery circulars and research datasets from 2016A&A...594A..13P, SOUSA, 2011ApJ...737..103S, ATel 10638. 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 SN2017gax? Cross-Identifications
Throughout global alert streams and survey databases, SN2017gax has also been designated as:
AT2017gax, DLT17ch, Gaia17cgy. 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 SN2017gax contribute to measuring the Hubble Constant and the scale of the cosmos? Cosmology & Distance Ladder
As a core-collapse supernova, SN2017gax 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 SN2017gax be detected on Earth? Multi-Messenger Astronomy
Core-collapse supernovae like SN2017gax 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 SN2017gax 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), SN2017gax occurred at a distance of 64.3 Million Light-Years. While historical naked-eye supernovae occurred within our Milky Way or its immediate satellites, modern discoveries like SN2017gax allow astrophysicists to probe diverse galactic environments, metallicities, and stellar populations across the broader universe.
Can I see SN2017gax tonight with a backyard telescope or binoculars? Backyard Observation
Unknown — no measured brightness. SN2017gax was discovered 3379 days ago (2017/08/14), 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 SN2017gax 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 64.3 Million Light-Years, the inverse-square law dilutes the radiation by quintillions of times, making SN2017gax completely harmless to our biosphere and purely a fascinating spectacle for human exploration.
Data sourced from IAU TNS, ALeRCE, WISeREP, and the sne.space.
View All General Astrophysics FAQs →