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Swift detection of a serendipitous source close-by to SN 2009ip

ATel #4444; S. Campana (INAF- OA Brera)
on 1 Oct 2012; 21:29 UT
Credential Certification: Sergio Campana (campana@merate.mi.astro.it)

Subjects: X-ray, Supernovae, Transient

Referred to by ATel #: 4457, 4499

Swift X-ray Telescope (XRT) observed the Type-IIn SN 2009ip for 45 ks. The observation campaign started on Sept. 4, 2012, well in advance of the important changes in the spectrum firstly detected on Sept. 15-16, 2012 by Smith & Mauerhan (2012, ATel #4412). SN 2009ip is not detected in the summed image with an upper limit of 5.67x10^{-4} c/s (obtained with XIMAGE/sosta). This improves the limit by Margutti et al. (2012, ATel #4414) by a factor of ~10. Assuming a photon index spectrum with photon index Gamma=2 and a Galactic column density, this translates into an absorbed flux of ~2x10^{-14} erg/s/cm2. For a distance of 24 Mpc, this corresponding to a luminosity of ~2x10^{39} erg/s. A source close-by to SN 2009ip is detected in the 45 ks Swift XRT image. The source is very faint and can be revealed only in the summed image, with no obvious rise in the latest observations. The source count rate is (4.0+/-1.4)x10{-4} c/s and its position is: RA(J2000) : 22 23 09.32 Dec(J2000): -28 55 50.2 The error radius is difficult to estimate given the source faintness. We conservatively quote 7.0 arcsec (90% c.l.). The source lies at 14 arcsec from SN 2009ip (Maza et al. 2009, CBET 1928). We thank the Swift team for scheduling these ToO observations.