{
  "bibcode": "2015GCN.18536....1D",
  "body": "P. D'Avanzo, A. Melandri (INAF-OAB), S. Piranomonte (INAF-OAR), E. Cappellaro, L. Tomasella (INAF-OAPd), E. Brocato (INAF-OAR), M. Branchesi (Urbino University/INFN Firenze), E. Palazzi (INAF-IAFS Bo), L. A. Antonelli, (INAF-OAR), P. Astone (INFN-Roma), S. Campana (INAF-OAB), E. Cappellaro (INAF-OAPd), S. Covino (INAF-OAB), V. D'Elia (INAF-ASDC), F. Getman (INAF-OAC), G. Giuffrida (INAF-ASDC), A. Grado (INAF-OAC), G.Greco (Urbino University/INFN Firenze), L. Limatola (INAF-OAC), M. Lisi (INAF-OAR), S. Marinoni (INAF-ASDC), P. Marrese (INAF-ASDC), L. Nicastro (INAF-IASF Bo),  Pian (SNS-Pisa), L. Pulone (INAF-OAR), F. Ricci (Sapienza University), G. Stratta (Urbino University/INFN Firenze), V. Testa (INAF-OAR), A. Fiorenzano, W. Boschin, Albar Garcia de Gurtubai Escudero (INAF-TNG), on behalf of the INAF Gravitational Astronomy group report: \n\nWe report the result of the analysis of the optical transients iPTF15dkm and iPTF15dlj reported by Singer et al. (LIGO/Virgo Circular #18497), located in the skymap of the advanced LIGO and Virgo trigger G194575 (Singer et al., LIGO/Virgo Circular #18442).\nWe observed with the 3.6m Italian TNG telescope (Canary Islands, Spain), equipped with DOLORES  camera in both imaging and spectroscopic mode on 2015 Oct 29. \n\nThe optical transients are clearly detected. At a mean time of 20:07:03 UT and 20:50:24 UT we measure a magnitude of r = 17.95  +/-   0.23 (AB) and r = 16.64  +/-   0.35 (AB) for iPTF15dkm and iPTF15dlj respectively.\n\nBased on a preliminary calibration, the spectrum of iPTF15dkm,  obtained on\n2015 Oct 29 at 20:57:30 UT, shows that the transient is a Type II SN\nabout ten days after explosion at z~0.026, as derived from the position of\nthe SN main features. The best fit is with SN2006bp (Quimby et al. 2007, ApJ 666, 1093).\nThe transient is close to SDSS galaxy SDSS J233717.65-033159.2,\nwith photometric redshift z~0.036.\n\nThe spectrum of iPTF15dlj, obtained on Oct 29 at 21:37:46 UT, shows that\nthe transient is a type II SN about 2-3 weeks after explosion, around z~0.01.\nThe best match is with SN 2005cs  (Pastorello et al. 2006,\nMNRAS, 370, 1752). The transient is close to the galaxy J011902.90+100005.5\n(photometric redshift z~0.05 from SDSS).\n\nClassification was done with GELATO (Harutyunyan et al. 2008, A&A, 488, 383)\nand SNID (Blondin and Tonry 2007, ApJ, 666, 1024).",
  "circularId": 18536,
  "createdOn": 1446212734000,
  "email": "silvia.piranomonte@oa-roma.inaf.it",
  "subject": "LIGO/Virgo G194575: INAF-TNG follow-up of iPTF15dkm and iPTF15dlj",
  "submitter": "Silvia Piranomonte at INAF  <silvia.piranomonte@oa-roma.inaf.it>",
  "eventId": "LIGO/Virgo G194575"
}