What type of supernova is PSc490402 and what kind of star exploded?
Astrophysics & Progenitor
PSc490402 is spectroscopically classified as a Type Ia supernova, consistent with a thermonuclear explosion involving a carbon-oxygen white dwarf. Type Ia events are used as distance indicators via empirical relations such as the Phillips relation, but that cosmological utility does not identify which binary channel (single-degenerate accretion, double-degenerate merger, or sub-Chandrasekhar detonation) produced this object.
What was the progenitor star doing in the millions of years leading up to PSc490402?
Astrophysics & Progenitor
No unique progenitor history is established for PSc490402. Type Ia spectral classification is consistent with a thermonuclear explosion of a carbon-oxygen white dwarf, but it does not identify which binary pathway produced this event. Leading models include single-degenerate accretion toward the Chandrasekhar mass, double-degenerate white-dwarf mergers, and sub-Chandrasekhar helium-shell detonations. Distinguishing these requires population statistics, early-time spectra, or remnant searches that are not established for this individual object. Claims that this white dwarf accreted for millions of years, or that it approached 1.4 solar masses, are general theory—not documented facts about PSc490402.
How far away is PSc490402 from Earth and how old is the light reaching us?
Cosmic Distance & Time
The distance to PSc490402 has not been measured. No spectroscopic redshift or luminosity distance is published for this transient, so neither its distance from Earth nor its lookback time can be stated. A redshift requires a spectrum, and a photometric redshift requires multi-band imaging that has not been reported. Without a distance, its intrinsic luminosity and total energy release are also undetermined. Check the sources below for follow-up spectroscopy or host-galaxy identification.
What does the cosmological redshift of PSc490402 tell us about the expansion of space?
Cosmic Distance & Time
No spectroscopic redshift has been measured for PSc490402. 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 PSc490402 become at its peak, and how many Suns does that equal?
Explosion Energetics
At peak brightness, PSc490402 achieved an apparent magnitude of 22.33 around 2013/03/09.
How much total energy was released by PSc490402, and where did that energy go?
Explosion Energetics
Type Ia events are typically associated with a kinetic energy scale of order 10⁵¹ ergs, with little neutrino emission compared to core-collapse. That is a class expectation—not a calorimetry measurement for PSc490402.
How fast are the supernova ejecta and shockwave of PSc490402 expanding through space?
Explosion Energetics
No ejecta velocity is measured for PSc490402. 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 Ia events typically show ejecta speeds of order ~11,000 km/s near maximum, but that class scale is not a measurement of PSc490402.
What powers the prolonged glow of PSc490402 weeks and months after detonation?
Radioactive Engine
After peak, Type Ia light curves are generally powered by the radioactive chain ⁵⁶Ni → ⁵⁶Co → ⁵⁶Fe (half-lives ≈6.1 d and ≈77.2 d). Typical Type Ia events synthesize of order half a solar mass of freshly made Nickel-56 (which later decays into Iron-56); that is a class expectation, not a measured nickel mass for PSc490402. Estimating M(⁵⁶Ni) for this object requires a bolometric light-curve fit that is not published here.
What chemical elements did PSc490402 create and disperse into the universe?
Nucleosynthesis & Elements
Type Ia explosions are efficient producers of iron-peak elements via thermonuclear burning. Models typically yield substantial ⁵⁶Ni (which decays to stable ⁵⁶Fe), plus silicon, sulfur, calcium, and related species—consistent with the Si II features used in classification. No object-specific nucleosynthetic yield has been published for PSc490402; asserting that this event synthesized half a solar mass of iron would overstate the evidence.
Did PSc490402 leave behind a black hole, a neutron star, or nothing at all?
Cosmic Remnant
Nothing remains at the center. Because a Type Ia supernova involves the total thermonuclear disruption of the progenitor white dwarf, the entire star was incinerated and flung into space. There is no central neutron star, pulsar, or black hole left behind. The star's entire mass now exists as an expanding gaseous shell traveling through the host galaxy.
What will PSc490402'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 PSc490402. 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 PSc490402 explode, and where is it located relative to the galactic center?
Galactic Environment
No host galaxy is identified for PSc490402 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 PSc490402 located in the night sky and which constellation is it in?
Sky Coordinates
In the celestial sphere, PSc490402 is located at Right Ascension 08:43:02.525 and Declination +45:03:21.34, situated in the constellation Lynx (The Lynx). Because its declination is +45:03:21.34, it is primarily placed in the Northern celestial hemisphere.
How much Milky Way interstellar dust obscures our view of PSc490402?
Interstellar Dust
Along this line of sight, the catalog records a Milky Way foreground color excess of E(B−V) = 0.0233 mag (source: published extinction estimate), corresponding to roughly A_V ≈ 0.07 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 PSc490402 monitored?
Astronomical Observations
No calibrated photometry is published for PSc490402. 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 PSc490402's chemical makeup?
Astronomical Observations
No spectrum has been published for PSc490402. 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 PSc490402 and how was it first detected?
Discovery & History
PSc490402 was officially reported on 2013/03/03 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 PSc490402?
Scientific Research
Data for PSc490402 are compiled from international astronomical notices, the IAU Transient Name Server (TNS), and peer-reviewed astrophysical journals.
How does PSc490402 contribute to measuring the Hubble Constant and the scale of the cosmos?
Cosmology & Distance Ladder
Because PSc490402 is a Type Ia supernova, it serves as an indispensable rung on the Cosmic Distance Ladder. Astrophysicists utilize the Phillips relation—a tight empirical correlation between peak absolute magnitude and light curve decline rate (Δm₁₅)—to standardize its luminosity. By comparing this calibrated intrinsic brightness with observed apparent magnitude, researchers calculate precise geometric distances across the universe, providing key empirical tests of the Hubble constant (H₀) and dark energy.
Could gravitational waves or neutrinos from PSc490402 be detected on Earth?
Multi-Messenger Astronomy
For thermonuclear explosions like PSc490402, gravitational wave and neutrino emissions are negligible compared to core-collapse events. However, multi-messenger radio and X-ray observations are crucial: detecting synchrotron radio emission would reveal circumstellar gas shed by a companion star, helping settle the century-old debate between single-degenerate and double-degenerate white dwarf progenitor channels.
How does PSc490402 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), the distance to PSc490402 is not measured, so no such comparison can be drawn. While historical naked-eye supernovae occurred within our Milky Way or its immediate satellites, modern discoveries like PSc490402 allow astrophysicists to probe diverse galactic environments, metallicities, and stellar populations across the broader universe.
Can I see PSc490402 tonight with a backyard telescope or binoculars?
Backyard Observation
Unknown — no measured brightness. PSc490402 was discovered 5005 days ago (2013/03/03), 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 PSc490402 pose any threat to Earth?
Planetary Safety
Earth is in no danger from PSc490402. The astrophysical 'lethal kill zone' for a supernova to damage our ozone layer is roughly 50 to 100 light-years. This transient is far outside the solar neighbourhood: it was discovered by a wide-field survey at a magnitude only reachable for an extragalactic object, and any transient in our own galaxy within that radius would have appeared far brighter than the ~18th magnitude reported here. Its exact distance is unmeasured, but the detection brightness alone rules out any nearby threat.
