English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

The main progenitor candidate of Type Ia supernovae (SNe Ia) is white dwarfsin binary systems where the companion star is another white dwarf (doubledegenerate system) or a less evolved non-degenerate star with R* >~ 0.1 Rsun(single degenerate system), but no direct observational evidence exists thattells which progenitor system is more common. Recent studies suggest that thelight curve of a supernova shortly after its explosion can be used to set alimit on the progenitor size, R*. Here, we report a high cadence monitoringobservation of SN 2015F, a normal SN Ia, in the galaxy NGC 2442 starting about84 days before the first light time. With our daily cadence data, we catch theemergence of the radioactively powered light curve, but more importantly detectwith a > 97.4% confidence a possible dim precursor emission that appears atroughly 1.5 days before the rise of the radioactively powered emission. Thesignal is consistent with theoretical expectations for a progenitor systeminvolving a companion star with R* = ~0.1 -- 1 Rsun or a prompt explosion of adouble degenerate system, but inconsistent with a typically invoked size ofwhite dwarf progenitor of R* ~ 0.01 Rsun. Upper limits on the precursoremission also constrain the progenitor size to be R* < 0.1 Rsun, and acompanion star size of R* < ~1.0 Rsun, excluding a very large companion star inthe progenitor system. Additionally, we find that the distance to SN 2015F is23.9 +-0.4 Mpc.

The Very Early Light Curve of SN 2015F in NGC 2442: A Possible Detection of Shock-Heated Cooling Emission and Constraints on SN Ia Progenitor System