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Probable progenitor for SN 2009kr in NGC 1832

ATEL # 2312; W. Li, A. V. Filippenko, and A. A. Miller (UC Berkeley); J.-C. Cuillandre (CFHT corporation); N. Elias-Rosa and S. D. Van Dyk (Spitzer)
on 24 Nov 2009; 5:09 UT
Password Certification: Weidong Li (

Subjects: Optical, Nova, Supernova, Transients, Variables

We report that we have isolated a probable progenitor for the Type II SN 2009kr in Hubble Space Telescope (HST) images of NGC 1832 (GO program 10877) taken with the Wide Field Planetary Camera 2 (WFPC2). Geometrical transformation between a combined 160 s r-band image taken with the 3.6-m CFHT's MegaCam on Nov 21.49 UT and the HST/WFPC2 images yields a precision of 0.43 WFPC2 pixel (0".043) for the supernova location on the WFPC2 images. Within the uncertainty of the SN position, an object is clearly detected in the F555W and F814W images, with a position of R.A. = 5h12m03s.247, Decl. = -15o41'53".10 (equinox 2000.0), a brightness of I = 23.6 mag, and a color of V-I = 1.0 mag. Correcting the photometry with the Milky Way reddening of E(B-V) = 0.073 mag (Schlegel et al. 1998, ApJ 500, 525), adopting a distance modulus to NGC 1832 of 32.0 mag, and assuming no host-galaxy reddening, the object has an absolute I-band magnitude of -8.5 and an intrinsic V-I color of 0.9 mag, consistent with a star having 20-25 solar masses. It is also possible that the object we identified is a compact star cluster given its brightness. More analysis is in progress and efforts will be made to further improve the astrometric precision. A finder chart for the possible progenitor is provided at

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