BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//CERN//INDICO//EN
BEGIN:VEVENT
SUMMARY:Searching for Precursor Outbursts in 2024jlf
DTSTART;VALUE=DATE-TIME:20261028T181900Z
DTEND;VALUE=DATE-TIME:20261028T182000Z
DTSTAMP;VALUE=DATE-TIME:20261024T225406Z
UID:indico-contribution-3684@nyx.physics.mcgill.ca
DESCRIPTION:Speakers: Ai Hua Li (Dunlap Institue for Astronomy & Astrophys
 ics)\nType IIn supernovae (SNe) are a subclass of Type II SNe characterize
 d by narrow hydrogen emission lines produced by interactions between SN ej
 ecta and surrounding circumstellar material (CSM). Some Type IIn SNe show 
 these features only briefly\, indicating less extended CSM and motivating 
 their classification as Type IIn-like SNe. The origin of this CSM remains 
 a major outstanding question.\n\nPrecursor outbursts are episodes of enhan
 ced mass loss from a progenitor prior to explosion theorized to contribute
  to CSM formation. They have been observed in approximately 25–50% of Ty
 pe IIn SNe\, but only one Type IIn-like progenitor has been linked to prec
 ursor activity. We therefore investigate possible pre-SN variability in th
 e progenitor of the Type IIn-like SN 2024jlf.\n\nUsing data from the ATLAS
  Forced Photometry Service\, we applied the ATClean pre-SN variability ana
 lysis pipeline. ATClean cleans progenitor and control light curves\, searc
 hes for sustained signals across Gaussian-kernel timescales\, and estimate
 s detection efficiency by injecting simulated precursor outbursts into con
 trols.\n\nATClean detected sustained pre-SN signals across all tested time
 scales. Binning the cleaned progenitor light curve revealed >5σ detection
 s in the same time range. However\, difference images revealed variability
  in a nearby image artefact during the epoch of detections\, and ATClean
 ’s binning procedure is susceptible to outliers.\n\nFuture work such as 
 investigating the above artefacts and refining the ATClean binning procedu
 re is needed to determine the exact source of our detections\, thereby con
 straining pre-SN mass loss in IIn-like systems.\n\nhttps://nyx.physics.mcg
 ill.ca/event/587/contributions/3684/
LOCATION:Online 
URL:https://nyx.physics.mcgill.ca/event/587/contributions/3684/
END:VEVENT
END:VCALENDAR