Optical photometry of SN 2023ldh

During the rise to the Event B peak, the spectrum shows a blue continuum dominated by Balmer lines in emission with Lorentzian profiles, with a full width at half-maximum (FWHM) velocity of about 650 km/s. Later, in the post-peak phase, the spectrum reddens, and broader wings appear in the H{alpha} line profile. Metal lines are well visible with P Cygni profiles and velocities of about 2000km/s.

Beginning around three months past maximum and until very late phases, the Ca II lines become among the most prominent features, while H{alpha} is dominated by an intermediate-width component with a boxy profile. Although SN 2023ldh mimics the evolution of other SN 2009ip-like transients, it is slightly more luminous and has a slower photometric evolution. The surprisingly homogeneous observational properties of SN 2009ip-like events may indicate similar explosion scenarios and similar progenitor parameters.