Data legend
Definitions, notation, and units used throughout the Type Iax supernova catalogue. Reported measurements retain their source, uncertainty, limits, and method metadata.
Catalogue & coverage
- Name
- The preferred catalogue designation. When an official supernova designation exists, the SN YYYYabc form is used; established survey designations are retained for other objects.
- Photometry available
- Shows whether photometric light-curve data are available. The catalogue also gives the number of passbands and measurements and, when a consistent time range can be determined, the covered duration.
- Spectroscopy available
- Shows whether spectra are available, together with the number of spectra and, when all observation dates are known, the covered duration.
- Spectral series
- The source-catalogue count of individual spectroscopic observations recorded over time.
- Reference
- The publication or publications from which the corresponding measurements were compiled, identified by author and year with a DOI, arXiv identifier, or bibcode when available.
Position & host
- RAdeg
- Right ascension of the supernova position, expressed in decimal degrees.
- Decdeg
- Declination of the supernova position, expressed in decimal degrees.
- zdimensionless
- Host-galaxy redshift derived from the flow-corrected recession velocity using z = vrec/c.
- DistanceMpc
- Where relevant non-Hubble-flow estimates are available, the source catalogue reports their mean. These may include Tully–Fisher, SN Ia, or Cepheid distances. Otherwise the site calculates d = vrec/H0, with H0 = 73 km s−1 Mpc−1, and labels the result as calculated.
- E(B−V)MWmag
- Milky Way colour excess along the line of sight, used to quantify foreground dust extinction.
- E(B−V)hostmag
- Host-galaxy colour excess along the line of sight to the supernova, used to quantify extinction by dust in the host galaxy.
Light curves
- mB, mV, mrmag
- Peak apparent magnitudes in the Johnson B and V passbands and the Sloan r passband.
- MB, MV, Mrmag
- Peak absolute magnitudes based on the compiled distance and the adopted Milky Way and host-galaxy reddening or extinction corrections.
- tmax(B), tmax(V), tmax(r)MJD
- The epoch of maximum light in each passband, expressed as a Modified Julian Date.
- Δm15(B), Δm15(V), Δm15(r)mag
- The magnitude decline during the 15 days after maximum light in a passband: m(tmax + 15 d) − m(tmax).
- texpMJD
- The estimated epoch of explosion.
- trise(r)days
- The reported rise time in the r passband.
Physical properties
- Lbol1042 erg s−1
- Peak bolometric luminosity.
- M56NiM☉
- The estimated mass of radioactive nickel-56 synthesised in the explosion.
- MejM☉
- The estimated ejecta mass.
- vTARDISkm s−1
- Photospheric velocity at V-band maximum estimated with one-dimensional TARDIS radiative-transfer modelling.
- vSYN++km s−1
- Photospheric velocity at V-band maximum estimated with parametrised SYN++ spectral modelling.
- vph (BlueSHIFT)km s−1
- Photospheric velocity near maximum light inferred from suitable absorption-line blueshifts. The dedicated Si II λ6355 measurement is listed separately.
- vSi II λ6355km s−1
- The apparent line velocity inferred from the blueshift of the Si II λ6355 absorption minimum.
Reading values
- ± marks a symmetric uncertainty; separate lower and upper values mark an asymmetric uncertainty.
- <, ≤, >, ≥ mark reported limits, while a value pair marks a reported range.
- N/A means that no usable value is available; it is not interpreted as zero.
- When publications report different measurements, the site keeps them with their respective sources rather than averaging them at display time.