Extended Data Figure 6 : The nature of the increased flux during the brightest peak of iPTF14hls.

From: Energetic eruptions leading to a peculiar hydrogen-rich explosion of a massive star

Extended Data Figure 6

Spectra of iPTF14hls expressed in terms of normalized flux density as a function of rest-frame wavelength taken on rest-frame day 207 (right before the rise to the brightest peak in the light curve) and day 232 (at the brightest peak in the light curve) after discovery (solid lines) are shown. The similarity of the spectra indicates that the increase of about 50% in luminosity observed in the light curve between the two epochs is equal at all wavelengths. If the increase were due only to the continuum flux, then the line emission on day 232 would have been diluted by the continuum (as simulated by the dashed line).