分类: 天文学 >> 天文学 提交时间: 2023-02-19
摘要: We report analysis using the James Webb Space Telescope (JWST) to identify a candidate progenitor star of the Type II-plateau supernova SN 2022acko in the nearby, barred spiral galaxy NGC 1300. To our knowledge, our discovery represents the first time JWST has been used to localize a progenitor system in pre-explosion archival Hubble Space Telescope (HST) images. We astrometrically registered a JWST NIRCam image from 2023 January, in which the SN was serendipitously captured, to pre-SN HST F160W and F814W images from 2017 and 2004, respectively. A star corresponding precisely to the SN position has been isolated with reasonable confidence, although a ~2.9 sigma difference exists between the measured position for the star from HST and the transformed SN position from JWST. That star has a spectral energy distribution and overall luminosity consistent with a single-star model having an initial mass somewhat less than the canonical 8 Msun theoretical threshold for core collapse, although the star's initial mass is inconsistent with that of a super-asymptotic giant branch star which might be a forerunner of an electron-capture SN. The properties of the progenitor alone imply that SN 2022acko is a relatively normal SN II-P, albeit most likely a low-luminosity one. The progenitor candidate should be confirmed with follow-up HST imaging at late times, when the SN has sufficiently faded. This potential use of JWST opens a new era of identifying SN progenitor candidates at high spatial resolution.