SN2026acxa: What Happened, Distance & Viewing Guide

Q: What type of supernova is SN2026acxa and what kind of star exploded?

SN2026acxa is a stripped-envelope supernova (Type Ic-BL), 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.

Q: How far away is SN2026acxa from Earth and how old is the light reaching us?

SN2026acxa has a luminosity distance of approximately 117.4 Million Light-Years (redshift z = 0.008089, d_L = 35.989). Under a flat ΛCDM cosmology (H₀≈70 km/s/Mpc, Ωₘ≈0.3), the corresponding lookback time is ≈112 Myr — when the light set out 112.3 million years ago during the Cretaceous period when Tyrannosaurus rex and Triceratops walked the planet. Luminosity distance is larger than the light-travel distance because cosmic expansion stretches the path; the two must not be equated.

Q: What does the cosmological redshift of SN2026acxa tell us about the expansion of space?

SN2026acxa exhibits a measured spectroscopic redshift of z = 0.0081. The cockpit reports a user-facing recession velocity of 2,415.2 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 (≈2,425 km/s) is a different low-z approximation and is not mixed here.

Q: How fast are the supernova ejecta and shockwave of SN2026acxa expanding through space?

No ejecta velocity is measured for SN2026acxa. 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 Ic-BL events typically show ejecta speeds of order ~22,000 km/s near maximum, but that class scale is not a measurement of SN2026acxa.

          🔭 Deep Field (~2.1′ FOV) · DSS2 Optical (China-VO mirror)
        

● SN2026acxa Explosion Site

High-magnification deep optical view into SN2026acxa's host environment. Pan and scroll to explore the cosmic neighborhood where this star exploded.

⚡ Quick Observer Facts & Telemetry

IAU Transients DB

🌐 Distance to Earth

117.4 Million Light-Years

Lookback Cosmic Time

✨ Peak Brightness

Mag 15.15

Astro Camera (CCD)

☀️ Peak Radiance

955.0 million Suns

Combined Stellar Energy

🚀 Shock Velocity

Not measured

No spectral ejecta velocity

🌌 Host Galaxy

Field Transient Host

Center Coincident

🧭 Constellation

Capricornus

The Sea Goat

💥 Explosion Physics

Type Ic-BL

Core-Collapse Supergiant

📅 Discovered On

2026/09/25

BTSbot_bot

CHAPTER I

A Core-Collapse Class Transient

On 2026/09/25, astronomers scanning the heavens flagged a sudden, violent pinpoint of light that had flared into visibility. Designated SN2026acxa, it represents a catastrophic stellar explosion classified as a Type Ic-BL supernova.

SN2026acxa is classified in a core-collapse spectroscopic family. Events of this class are generally linked to the death of a massive star after successive nuclear burning stages, but no unique progenitor mass, lifetime, or pre-explosion identification is established for this object. The narrative of onion-shell fusion ending in iron-core collapse describes the class model, not a measured biography of SN2026acxa.

Astrophysical Mechanism Summary

Type: Type Ic-BL • Progenitor: Massive Red/Stripped Supergiant Star • Velocity: Not measured

CHAPTER II

A Message Across Deep Cosmic Time

SN2026acxa has a luminosity distance of approximately 117.4 Million Light-Years (redshift z = 0.008089). That figure is not the light-travel time: under flat ΛCDM the lookback time is ≈112 Myr, when the light set out 112.3 million years ago during the Cretaceous period when Tyrannosaurus rex and Triceratops walked the planet.

Luminosity distance incorporates cosmic expansion and exceeds the light-travel distance. The two quantities must be reported separately.

CHAPTER III

Incandescence of 955.0 million Suns

At the height of the outburst around 2026/09/26, SN2026acxa surged to a peak apparent magnitude of 15.15 and an intrinsic absolute magnitude of -17.62. At that instant, this single dying star radiated with the collective power of approximately 955.0 million Suns combined, outshining whole dwarf galaxies.

The total energy released by the cataclysm was on the order of 10⁵¹ to 10⁵³ ergs. Over 99% of this energy was emitted within the first 10 seconds as a dense burst of trillions of neutrinos, with only 1% driving the visible blast wave.

CHAPTER IV

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 Ic-BL light curves; an object-specific nickel mass for SN2026acxa 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.

CHAPTER V

Cosmic Kiln: Seeding the Elements of Life

Supernovae enrich galaxies with heavy elements. Events of SN2026acxa's class are associated with oxygen-group and intermediate-mass products (O, C, Ne, Mg, Si) in galactic chemical-evolution models. No measured elemental yields are published for SN2026acxa.

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.

CHAPTER VI

Galactic Setting in Capricornus

No host galaxy is identified for SN2026acxa in this catalog record . In our terrestrial sky, it resides in the constellation Capricornus (The Sea Goat) at Right Ascension 21:02:30.263 and Declination -19:27:41.91.

CHAPTER VII

The Scientific Surveillance Campaign

Following its discovery by BTSbot_bot, observatories worldwide swung their lenses toward SN2026acxa. In the sne.space, SN2026acxa is documented across 6 photometric measurements in passbands such as g, g-ZTF, i, r and 1 spectroscopic epochs. These multi-wavelength observations allow astrophysicists to model the expanding photosphere, measure shock velocities, and probe circumstellar interactions.

CHAPTER VIII

Stargazer's Field Guide: Can You See It Tonight?

Can I see it tonight? Multi-epoch light curve supports an ongoing outburst.

Discovered 49 days ago (2026/09/25). Cataloged peak 2026/09/26 (48d ago; rest-frame phase +47.6d). Cataloged/observed peak: m = 15.15 on 2026/09/26. Latest observed: m = 15.43 on 2026/09/26 (MJD 61309.3).

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 = 15.43 on 2026/09/26 (MJD 61309.3). Current brightness trend is unknown (last observation 2026/09/26 (MJD 61309.3); same-band recent pair unavailable or stale).

Instrument Class & Aperture	Sensitivity Limit	Cataloged Peak (m=15.15 on 2026/09/26)	Current Brightness Tonight
Naked Eye Dark sky site (Bortle 1–3) with no optical aid	m ≤ 6.0	Requires larger aperture (limit m ≤ 6.0)	No reliable estimate
Binoculars (50mm) Standard 7x50 or 10x50 handheld binoculars	m ≤ 9.5	Requires larger aperture (limit m ≤ 9.5)	No reliable estimate
Small Backyard Scope (4" / 100mm) Entry 4-inch (100mm) refractor / reflector	m ≤ 12.0	Requires larger aperture (limit m ≤ 12.0)	No reliable estimate
Medium Amateur Scope (8"–12") 8-inch to 12-inch Dobsonian or Schmidt-Cassegrain	m ≤ 14.5	Requires larger aperture (limit m ≤ 14.5)	No reliable estimate
Amateur CMOS Rig Cooled monochrome/color CMOS camera with multi-hour stack	m ≤ 19.5	✅ Reachable	No reliable estimate
2m–3m Research Telescope University or regional observatory (e.g. Palomar 60", Calar Alto)	m ≤ 22.0	✅ Reachable	No reliable estimate
Giant 8m–10m Observatories Keck (10m), VLT (8.2m), Gemini, Subaru optical imaging	m ≤ 25.0	✅ Reachable	No reliable estimate
Space Observatories Only Hubble Space Telescope (WFC3) / JWST (NIRCam deep stack)	m ≤ 30.0	✅ Reachable	No reliable estimate

Planetary Safety Note: Even though SN2026acxa was a titanic explosion, our planet sits safely outside the lethal 50–100 light-year kill zone. At a distance of 117.4 Million Light-Years, the blast poses zero physical hazard to Earth's biosphere.

🌌 Cosmic Neighbors & Contemporaries 105,868+ transients indexed

Cataloged transients closest to SN2026acxa in discovery time, spatial sky neighborhood, and cosmological redshift:

⏱️ Closest in Time

SN2026ahyg +6d after

Type IIP 2026/10/01 · Mag 19.2701

SN2026afqb +10d after

Type Ia 2026/10/05 · Mag 20.6842

SN2026aevi +11d after

Type Ia 2026/10/06 · Mag 19.99

🔭 Closest on the Sky

SN2022kye 10.9′ away

Type II Discovered 2022/05/25

AT2026airw 19.0′ away

Type unclassified Discovered 2026/11/08

AT2026aisa 31.3′ away

Type unclassified Discovered 2026/11/08

🌌 Same Cosmic Era (Redshift)

AT2022crv z = 0.008091

Type Ib ~110.8 Mly (approx.)

SN2018hfm z = 0.008087

Type II ~110.8 Mly (approx.)

AT2020po z = 0.008086

Type Candidate ~110.8 Mly (approx.)

❓ Frequently Asked Questions About SN2026acxa

Scientific & observational Q&As indexed from astronomical databases & the sne.space

What type of supernova is SN2026acxa and what kind of star exploded? Astrophysics & Progenitor

SN2026acxa is a stripped-envelope supernova (Type Ic-BL), 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 SN2026acxa? Astrophysics & Progenitor

The specific progenitor of SN2026acxa 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 SN2026acxa.

How far away is SN2026acxa from Earth and how old is the light reaching us? Cosmic Distance & Time

SN2026acxa has a luminosity distance of approximately 117.4 Million Light-Years (redshift z = 0.008089, d_L = 35.989). Under a flat ΛCDM cosmology (H₀≈70 km/s/Mpc, Ωₘ≈0.3), the corresponding lookback time is ≈112 Myr — when the light set out 112.3 million years ago during the Cretaceous period when Tyrannosaurus rex and Triceratops walked the planet. 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 SN2026acxa tell us about the expansion of space? Cosmic Distance & Time

SN2026acxa exhibits a measured spectroscopic redshift of z = 0.0081. The cockpit reports a user-facing recession velocity of 2,415.2 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 (≈2,425 km/s) is a different low-z approximation and is not mixed here.

How bright did SN2026acxa become at its peak, and how many Suns does that equal? Explosion Energetics

At peak brightness, SN2026acxa achieved an apparent magnitude of 15.15 around 2026/09/26. Corrected for cosmic distance and foreground interstellar dust, its intrinsic absolute magnitude was -17.62. At this peak, the exploding star radiated with the incandescent brilliance of approximately 955.0 million Suns combined, briefly outshining the cumulative starlight of entire dwarf galaxies!

How much total energy was released by SN2026acxa, 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 SN2026acxa.

How fast are the supernova ejecta and shockwave of SN2026acxa expanding through space? Explosion Energetics

No ejecta velocity is measured for SN2026acxa. 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 Ic-BL events typically show ejecta speeds of order ~22,000 km/s near maximum, but that class scale is not a measurement of SN2026acxa.

What powers the prolonged glow of SN2026acxa 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 SN2026acxa. 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 SN2026acxa create and disperse into the universe? Nucleosynthesis & Elements

Events of SN2026acxa'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 SN2026acxa.

Did SN2026acxa leave behind a black hole, a neutron star, or nothing at all? Cosmic Remnant

A core-collapse explosion associated with SN2026acxa'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 SN2026acxa'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 SN2026acxa. 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 SN2026acxa explode, and where is it located relative to the galactic center? Galactic Environment

No host galaxy is identified for SN2026acxa in this catalog record. A blank host field means the association is unresolved here—it does not establish that the host is uncataloged, resolved in imaging, or securely linked by astrometry. Possible states (unidentified, hostless candidate, imaging detection without a catalog name, or a securely matched cataloged galaxy) require separate evidence that is not present in this field.

Where is SN2026acxa located in the night sky and which constellation is it in? Sky Coordinates

In the celestial sphere, SN2026acxa is located at Right Ascension 21:02:30.263 and Declination -19:27:41.91, situated in the constellation Capricornus (The Sea Goat). Because its declination is -19:27:41.91, it is favorably placed for Southern Hemisphere observatories.

How much Milky Way interstellar dust obscures our view of SN2026acxa? Interstellar Dust

Along this line of sight, the catalog records a Milky Way foreground color excess of E(B−V) = 0.0453 mag (source: 7), corresponding to roughly A_V ≈ 0.14 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 SN2026acxa monitored? Astronomical Observations

SN2026acxa was tracked across 6 photometric observations across a baseline of 1.1 days utilizing filter bands including g, g-ZTF, i, r. Data were captured by observatories and survey networks including ZTF, ZTF, GOTO. 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 SN2026acxa's chemical makeup? Astronomical Observations

Astronomers obtained 1 spectroscopic epochs for SN2026acxa from 4102.2 Å to 7992.1 Å by facilities including BL41. 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 SN2026acxa and how was it first detected? Discovery & History

SN2026acxa was officially reported on 2026/09/25 by BTSbot_bot. 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 SN2026acxa? Scientific Research

SN2026acxa is documented across 7 scientific references and archival data sources in the sne.space. These include discovery circulars and research datasets from Transient Name Server, 2026TNSTR3877....1R, The Open Supernova Catalog, ALeRCE / ZTF. 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 SN2026acxa? Cross-Identifications

Throughout global alert streams and survey databases, SN2026acxa has also been designated as: 2026acxa, AT2026acxa, SN 2026acxa, ZTF26abxkuhv. 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 SN2026acxa contribute to measuring the Hubble Constant and the scale of the cosmos? Cosmology & Distance Ladder

As a core-collapse supernova, SN2026acxa 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 SN2026acxa be detected on Earth? Multi-Messenger Astronomy

Core-collapse supernovae like SN2026acxa 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 SN2026acxa 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), SN2026acxa occurred at a distance of 117.4 Million Light-Years. While historical naked-eye supernovae occurred within our Milky Way or its immediate satellites, modern discoveries like SN2026acxa allow astrophysicists to probe diverse galactic environments, metallicities, and stellar populations across the broader universe.

Can I see SN2026acxa tonight with a backyard telescope or binoculars? Backyard Observation

Unknown — no measured brightness. SN2026acxa was discovered 49 days ago (2026/09/25), 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 SN2026acxa 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 117.4 Million Light-Years, the inverse-square law dilutes the radiation by quintillions of times, making SN2026acxa 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 →

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The Story of Supernova SN2026acxa