🔭 Deep Field (~2.1′ FOV) · Highest-Definition Optical Field (0.25″/pix)
● GRB 160425A Explosion Site
High-magnification deep optical view into GRB 160425A'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
10.79 Billion Light-Years
Lookback Cosmic Time
✨ Peak Brightness
Mag —
Research Scope
☀️ Peak Radiance
Hundreds of Millions of Suns
Combined Stellar Energy
🚀 Shock Velocity
~124,000 km/s
~41.4% Speed of Light
🌌 Host Galaxy
Field Transient Host
Center Coincident
🧭 Constellation
Telescopium
The Telescope
💥 Explosion Physics
Type LGRB
Core-Collapse Supergiant
📅 Discovered On
2016/04/25
Robotic Alert Network
HISTORIC BENCHMARK • OCTOBER 1604
Kepler's Supernova: The Last Naked-Eye Blast in the Milky Way
In October 1604, German astronomer and mathematician Johannes Kepler observed a brilliant new star in the constellation Ophiuchus, near a planetary conjunction of Mars, Jupiter, and Saturn. SN 1604 peaked at magnitude −2.5 (brighter than Jupiter) and holds a unique place in human history: it is the last supernova observed to detonate within our own Milky Way galaxy.
★ Landmark Dossier: SN 1604 (Kepler's Nova)
Observer: Johannes Kepler (Imperial Mathematician to Rudolf II) •
Type: Type Ia Thermonuclear •
Distance: ~20,000 Light-Years (Ophiuchus) •
Peak Apparent Magnitude: m ≈ −2.5 (Brighter than Jupiter) •
Milestone: Last observed Milky Way supernova in over 420 years!
Kepler documented the star's day-by-day brightness decline for over a year, publishing his monumental work De Stella Nova in Pede Serpentarii ("On the New Star in the Foot of the Serpent Bearer") in 1606. Like Tycho's star three decades earlier, Kepler's supernova proved that the cosmos was dynamic, laying the philosophical foundation for the Scientific Revolution and Newtonian mechanics.
CHANDRA X-RAY MYSTERIES
Dense Circumstellar Knots and the Progenitor Identity
High-resolution imaging with the Chandra X-ray Observatory revealed that Kepler's remnant is rich in dense, nitrogen-enhanced circumstellar knots. This indicates that before the white dwarf detonated, its companion star—likely an evolved asymptotic giant branch (AGB) red giant—shed immense wind material that was compressed by the supersonic blast wave.
Because our galaxy averages an expected 2 to 3 supernovae per century, the Milky Way is currently statistically overdue for its next naked-eye supernova. When the next galactic event detonates, global neutrino networks (SNEWS), gravitational wave detectors, and space observatories stand ready for immediate alert!
COORDINATES & OBSERVABILITY
Observing the Kepler Remnant
Located in the constellation Ophiuchus at RA 18:41:21.36, Dec -54:20:34.8, Kepler's remnant is an intriguing
target for deep narrowband astro-imaging during summer months in both hemispheres.
Can I see it tonight? No — this supernova is physically extinguished.
Supernovae are brief, explosive cosmic catastrophes. They brighten over days to weeks and then permanently fade into darkness as their radioactive nickel-56 and cobalt-56 fuel decays. This explosion occurred 10.5 years ago (2016/04/25). Accounting for cosmological time dilation at redshift z = 0.5550, the rest-frame age is +2454.7 days. By standard radioactive decay templates, its optical brightness has decayed by Δm ≈ 34.9 magnitudes to an estimated magnitude 52.9, rendering the transient undetectable to all ground-based observatories.
Instrument Breakdown: At its maximum brightness in 2016/04/25, it reached magnitude 18.00 (Amateur CMOS Rig). Tonight, pointing a telescope at these coordinates will reveal only the background host galaxy.
| Instrument Class & Aperture | Sensitivity Limit | At Peak Maximum (m=18.00) | Tonight (Est. m≈52.9) |
|---|---|---|---|
| Naked Eye Dark sky site (Bortle 1–3) with no optical aid |
m ≤ 6.0 | ❌ Below limit | ❌ Below limit |
| Binoculars (50mm) Standard 7x50 or 10x50 handheld binoculars |
m ≤ 9.5 | ❌ Below limit | ❌ Below limit |
| Small Backyard Scope (4" / 100mm) Entry 4-inch (100mm) refractor / reflector |
m ≤ 12.0 | ❌ Below limit | ❌ Below limit |
| Medium Amateur Scope (8"–12") 8-inch to 12-inch Dobsonian or Schmidt-Cassegrain |
m ≤ 14.5 | ❌ Below limit | ❌ Below limit |
| Amateur CMOS Rig Cooled monochrome/color CMOS camera with multi-hour stack |
m ≤ 19.5 | ✅ Detectable | ❌ Below limit |
| 2m–3m Research Telescope University or regional observatory (e.g. Palomar 60", Calar Alto) |
m ≤ 22.0 | ✅ Detectable | ❌ Below limit |
| Giant 8m–10m Observatories Keck (10m), VLT (8.2m), Gemini, Subaru optical imaging |
m ≤ 25.0 | ✅ Detectable | ❌ Below limit |
| Space Observatories Only Hubble Space Telescope (WFC3) / JWST (NIRCam deep stack) |
m ≤ 30.0 | ✅ Detectable | ❌ Below limit |
🌌 Cosmic Neighbors & Contemporaries
110,222+ Transients Indexed
Cataloged supernovae closest to GRB 160425A in discovery time, spatial sky neighborhood, and cosmological lookback epoch:
⏱️ Closest in Time
AT2016bsf
Exploded same day
Type Candidate
2016/04/25 · Mag 16.37
SN2016ccb
Exploded same day
Type Ia
2016/04/25 · Mag 17.2
AT2016cbw
+1d after
Type Candidate
2016/04/26 · Mag 17.5
❓ Frequently Asked Questions About GRB 160425A
Scientific & observational Q&As indexed from astronomical databases & the Open Supernova Catalog
What type of supernova is GRB 160425A and what kind of star exploded? Astrophysics & Progenitor
GRB 160425A is cataloged as a Type LGRB transient. It represents a catastrophic stellar explosion marking the terminal evolutionary endpoint of a star, liberating immense radiant energy and dispersing newly synthesized chemical elements into the host galaxy's interstellar medium.
What was the progenitor star doing in the millions of years leading up to GRB 160425A? Astrophysics & Progenitor
Before detonating as GRB 160425A, the progenitor lived a short, furious stellar life of roughly 10 to 30 million years. In its interior, temperatures and pressures reached astronomical extremes, burning through nuclear fuel in an 'onion-skin' arrangement of concentric shells: hydrogen burning into helium for millions of years, helium into carbon for hundreds of thousands of years, carbon into neon for centuries, oxygen into silicon for months, and silicon fusing into iron in mere days! Once iron filled the core, fusion could no longer extract energy, dooming the star to sudden gravitational collapse.
How far away is GRB 160425A from Earth and how old is the light reaching us? Cosmic Distance & Time
GRB 160425A is located approximately 10.79 Billion Light-Years from Earth (cosmological redshift z = 0.555, luminosity distance d_L = 3308). Because electromagnetic radiation travels at 299,792 km/s, the photons detected by modern telescopes began their cosmic voyage 10789.2 million years ago during the Paleozoic era, long before the first dinosaurs appeared on Earth. While that light traveled across intergalactic space, Earth's continents shifted and biological evolution shaped the history of our planet.
What does the cosmological redshift of GRB 160425A tell us about the expansion of space? Cosmic Distance & Time
GRB 160425A exhibits a measured spectroscopic redshift of z = 0.5550. Under Hubble's Law, this redshift corresponds to an apparent recessional velocity of approximately 166,384.8 km/s away from our Milky Way galaxy. This redshift is not motion through space alone, but the stretching of light waves as the fabric of the universe itself expanded during the millions of years the photons traveled to our telescopes.
How bright did GRB 160425A become at its peak, and how many Suns does that equal? Explosion Energetics
At peak brightness, GRB 160425A achieved an apparent magnitude of —. At this peak, the exploding star radiated with the incandescent brilliance of approximately hundreds of millions of Suns combined, briefly outshining the cumulative starlight of entire dwarf galaxies!
How much total energy was released by GRB 160425A, and where did that energy go? Explosion Energetics
The collapse of GRB 160425A's progenitor released a staggering 10⁵³ ergs of gravitational binding energy—more energy than our Sun will radiate across its entire 10-billion-year lifespan! Astonishingly, 99% of this titanic energy was emitted within 10 seconds in the form of trillions of nearly massless neutrinos. Only about 1% (10⁵¹ ergs) drove the physical kinetic blast wave, and a mere 0.01% (10⁴⁹ ergs) was radiated as the visible starlight observed by telescopes.
How fast are the supernova ejecta and shockwave of GRB 160425A expanding through space? Explosion Energetics
The debris and shockwave of GRB 160425A erupted into space at an astounding velocity of approximately 124,000 km/s (measured spectroscopically). This corresponds to roughly 41.4% of the speed of light (Mach 361,516 in air)! At this blistering speed, the expanding debris shell traverses the entire diameter of planet Earth in just 0.10 seconds, carving a giant bubble in the interstellar medium.
What powers the prolonged glow of GRB 160425A weeks and months after detonation? Radioactive Engine
While the initial flash of GRB 160425A was driven by shock breakout heating through the stellar envelope, its prolonged visibility over weeks and months was sustained by the radioactive decay of approximately 0.05 to 0.15 solar masses of Nickel-56 (⁵⁶Ni) forged in the core shock. As ⁵⁶Ni decays into ⁵⁶Co (half-life: 6.1 days) and then into stable ⁵⁶Fe (half-life: 77.2 days), gamma rays and positrons thermalize within the expanding ejecta, preventing the debris from instantly freezing in the vacuum of space.
What chemical elements did GRB 160425A create and disperse into the universe? Nucleosynthesis & Elements
Core-collapse supernovae like GRB 160425A are the primary creators of life-sustaining elements in the cosmos. The explosion manufactured and dispersed immense reservoirs of oxygen (the single most abundant heavy element in the universe), alongside carbon, nitrogen, neon, magnesium, silicon, sulfur, and calcium (which builds terrestrial bones and teeth). In the ultra-dense, neutron-rich shockwave, rapid neutron capture (r-process nucleosynthesis) forged heavy elements like gold, platinum, and uranium.
Did GRB 160425A leave behind a black hole, a neutron star, or nothing at all? Cosmic Remnant
The crushing core collapse of GRB 160425A's progenitor forged 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 GRB 160425A's explosion site look like in 1,000 to 10,000 years? Cosmic Remnant
Over the coming millennia, the explosion site of GRB 160425A will undergo three dramatic evolutionary epochs: During the next few centuries (Free Expansion phase), the ejecta shell will continue expanding at thousands of km/s. Between 500 and 10,000 years (the Sedov-Taylor adiabatic phase), the forward shock will sweep up hundreds of solar masses of interstellar gas, heating it to tens of millions of degrees and glowing in bright thermal X-rays (similar to the famous Cygnus Loop or Cassiopeia A). Eventually, the cooling shock will compress nearby giant molecular clouds, triggering the gravitational collapse of new stars and solar systems!
In which galaxy did GRB 160425A explode, and where is it located relative to the galactic center? Galactic Environment
GRB 160425A is associated with an uncataloged host galaxy. High-precision astrometry from optical sky surveys pins the explosion coordinates directly to the galaxy's underlying stellar population.
Where is GRB 160425A located in the night sky and which constellation is it in? Sky Coordinates
In the celestial sphere, GRB 160425A is located at Right Ascension 18:41:21.36 and Declination -54:20:34.8, situated in the constellation Telescopium (The Telescope). Because its declination is -54:20:34.8, it is favorably placed for Southern Hemisphere observatories.
How much Milky Way interstellar dust obscures our view of GRB 160425A? Interstellar Dust
Light from GRB 160425A passed through interstellar dust in the Milky Way, suffering a foreground color excess of E(B-V) = 0.050 magnitudes (based on Schlafly & Finkbeiner 2011 galactic recalibrations). This cosmic dust absorbs and scatters shorter blue wavelengths, dimming the transient by approximately A_V ≈ 0.16 magnitudes in visual light.
Across which photometric filter bands was GRB 160425A monitored? Astronomical Observations
Photometric light curves for GRB 160425A were acquired through standard astronomical alert streams and survey programs, measuring flux across optical passbands to map its peak magnitude and fading rate.
What did astronomical spectroscopy reveal about GRB 160425A's chemical makeup? Astronomical Observations
Spectroscopic observations of GRB 160425A confirmed its astrophysical classification by dissecting its light into individual wavelengths. Absorption and emission line features reveal the chemical composition, expansion velocity, and temperature of the expanding fireball.
Who discovered GRB 160425A and how was it first detected? Discovery & History
GRB 160425A was officially reported on 2016/04/25 by an automated robotic transient sky survey. 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 GRB 160425A? Scientific Research
Data for GRB 160425A are compiled from international astronomical notices, the IAU Transient Name Server (TNS), and peer-reviewed astrophysical journals.
How does GRB 160425A contribute to measuring the Hubble Constant and the scale of the cosmos? Cosmology & Distance Ladder
As a core-collapse supernova, GRB 160425A 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 GRB 160425A be detected on Earth? Multi-Messenger Astronomy
Core-collapse supernovae like GRB 160425A 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 GRB 160425A 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), GRB 160425A occurred at a distance of 10.79 Billion Light-Years. While historical naked-eye supernovae occurred within our Milky Way or its immediate satellites, modern discoveries like GRB 160425A allow astrophysicists to probe diverse galactic environments, metallicities, and stellar populations across the broader universe.
Can I see GRB 160425A tonight with a backyard telescope or binoculars? Backyard Observation
GRB 160425A exploded 10.5 years ago (2016/04/25). Optical transient emission has completely faded along its radioactive decay curve. Today, pointing a telescope at these coordinates reveals the expanding remnant nebula or an uncataloged host galaxy; the original optical transient is no longer detectable with amateur backyard equipment.
Does the radiation or shockwave from GRB 160425A 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 10.79 Billion Light-Years, the inverse-square law dilutes the radiation by quintillions of times, making GRB 160425A 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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