Early color photometry of a possible type Iax supernova 2023mnc: inferring the distance and progenitor constraints

Abstract

Abstract Early-time radioactive signals from type Ia supernovae (SNeIa) can provide important constraints on the explosion mechanism and the progenitor system. We present observations and analysis of SN 2023mnc, a SN Ia,

∼ 7

$\sim 7$ days following its discovery. Follow-up observations were conducted in optical bands, covering phases from

∼ − 4

$\sim -4$ days to

∼ 15

$\sim 15$ days relative to its r-band peak luminosity. The early photometry allows us to estimate the physical properties of the ejecta and characterize the possible divergence from a normal SN Ia; we were able to characterize it as a Type Iax supernova instead. The estimated date of explosion is

t 0

= 60130

$t_{0}=60130$ MJD and implies a short rise time of

t

r i s e

≈ 16

$t_{rise} \approx 16$ days. The apparent g-band peak magnitude and the post-peak decline rate are

m

m a x

( g ) = − 19.52 ± 0.47

$m_{max}(g)=-19.52\pm 0.47$ mag and

Δ

m 15

( g ) = 0.825 ± 1.635

$\Delta m_{15}(g)=0.825\pm 1.635$ mag, respectively. Based on the light curve fitting of standard SN Ia models, the distance modulus is predicted to be

37.98 ± 0.207

$37.98\pm 0.207$ mag for g-band measurements, and the SN is predicted to be

394.46 ± 38

$394.46\pm 38$ Mpc from Earth. Assuming a 56Ni powered radiative diffusion, the estimated bolometric light-curve peaks at

3.8 ×

10

41

$3.8 \times 10^{41}$ erg s−1 and indicates that only

0.017

M ⊙

$0.017 M_{\odot }$ of 56Ni was produced, making SN 2023mnc a moderate luminosity object in the Iax class with peak absolute magnitude of

M V

= − 15.3

$M_{V}=-15.3$ mag. Comparing the observed color evolution with the predicted by different models such as deflagration-to-detonation transition and pure-deflagration scenario, the latter one is favored. The photometry of SN 2023mnc offers a unique opportunity to examine the progenitor systems and ignition process of the SNe Iax, adding weight to the population study of such sub-class SNe.