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Observation by Robin Leadbeater: classification of SN 2021huw embedded in...

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Robin Leadbeater


Robin Leadbeater


2021 Apr 06 - 21:10


2021 Apr 14 - 19:54



  • ALPY 200 spectrograph
  • ATIK 428 camera
  • Celestron C11

5x1200 sec


Wigton Cumbria

Target name

SN 2021huw in CGCG 209-008


classification of SN 2021huw embedded in the galaxy core

About this image

After testing a technique to remove contamination from the host galaxy in spectra of supernovae close to the centre of the galaxy on known supernova SN 2021J, I used the same technique to officially confirm and classify the transient AT 2021huw as a type Ia supernova.  SN 2021huw is indistinguishable from the galaxy core in images and is only seen after subtraction of a galaxy template image. Similarly the galaxy dominates the spectrum taken at the location of the possible supernova. This can be subtracted  however using an archival spectrum of the galaxy from the Sloan Digital Sky Survey. The resulting spectrum was good enough to show the typical features of a type Ia supernova and the supernova identification program SNID confirms a good match to type Ia supernovae at the redshift of the host galaxy. The spectrum and classification was submitted to the Transient Name server.

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