Identification of a Possible Blue Progenitor for the Nearby Type Ib SN iPTF13bvn in HST Archival Images
ATel #5152; I. Arcavi, E. Ofek (WIS), Y. Cao (Caltech), C. Gelino (IPAC), O. Yaron, P. Vreeswijk, A. Gal-Yam (WIS), S. B. Cenko (Goddard), A. K.H. Kong, K. L. Li (NTHU)
on 20 Jun 2013; 18:11 UT
Credential Certification: Iair Arcavi (iair.arcavi@weizmann.ac.il)
Subjects: Optical, Supernovae
We obtained H-Band LGS AO imaging of iPTF13bvn (ATels #5137 ,#5142 ,#5151) on 2013-07-19 UT using the OSIRIS Imager mounted on the Keck I Telescope. Comparing these images with archival Hubble Space Telescope (HST) ACS/WFC F435W, F555W, and F814W images from 2005-03-10 UT (HST proposal 10187, PI: Smartt), we find that the SN position is coincident with star 3 from our previous report (ATel #5140; see http://goo.gl/0V69m ). We find 17 common registration stars which give an RMS of 0.04" in the registration of the images.
We use the DOLPHOT package (Dolphin 2000, PASP, 112, 1383) to measure the following magnitudes for this source:
Filter Mag Err S/N AbsMag
F435W 26.7 0.2 10.8 -5.2
F555W 26.5 0.2 9.5 -5.4
F814W 26.4 0.2 7.2 -5.5
These values are consistent with the progenitor being a WR star (Smartt 2009 ARA&A, 47, 63; see their Figure 7), though more work is required to classify the source conclusively.
For specification of the absolute magnitudes we use a distance modulus of 31.89 mag (corresponding to a distance of 23.9 Mpc) as provided in the NASA/IPAC Extragalactic Database (NED). We note that there is a 0.15 mag uncertainty stated for this value. No extinction corrections are performed.
If confirmed, this would be the first progenitor identification for a Type Ib supernova.
We thank S. Tendulkar for assistance in reducing the OSIRIS data. Additional analysis is ongoing.
