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/

Global: Zendy Plus annual

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

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Super-luminous supernovae (SLSNe) are rare events defined as beingsignificantly more luminous than normal terminal stellar explosions. The sourceof the extra powering needed to achieve such luminosities is still unclear.Discoveries in the local Universe (i.e. $z<0.1$) are scarce, but afford densemulti-wavelength observations. Additional low-redshift objects are thereforeextremely valuable. We present early-time observations of the type I SLSNASASSN-18km/SN~2018bsz. These data are used to characterise the event andcompare to literature SLSNe and spectral models. Host galaxy properties arealso analysed. Optical and near-IR photometry and spectroscopy were analysed.Early-time ATLAS photometry was used to constrain the rising light curve. Weidentified a number of spectral features in optical-wavelength spectra andtracked their time evolution. Finally, we used archival host galaxy photometrytogether with HII region spectra to constrain the host environment.ASASSN-18km/SN~2018bsz is found to be a type I SLSN in a galaxy at a redshiftof 0.0267 (111 Mpc), making it the lowest-redshift event discovered to date.Strong CII lines are identified in the spectra. Spectral models produced byexploding a Wolf-Rayet progenitor and injecting a magnetar power source areshown to be qualitatively similar to ASASSN-18km/SN~2018bsz, contrary to mostSLSNe-I that display weak/non-existent CII lines. ASASSN-18km/SN~2018bszdisplays a long, slowly rising, red 'plateau' of $>$26 days, before a steeper,faster rise to maximum. The host has an absolute magnitude of --19.8 mag ($r$),a mass of M$_{*}$ = 1.5$^{+0.08}_{-0.33}$ $\times$10$^{9}$ M$_{\odot}$ , and astar formation rate of = 0.50$^{+2.22}_{-0.19}$ M$_{\odot}$ yr$^{-1}$. A nearbyHII region has an oxygen abundance (O3N2) of 8.31$\pm$0.01 dex.

A nearby superluminous supernova with a long pre-maximum 'plateau' and strong CII features