Artículo
The Emergence of the Infrared Transient VVV-WIT-06
Fecha
2017-11Registro en:
Astrophysical Journal Letters, 849(2), art. no. L23.
2041-8205
DOI: 10.3847/2041-8213/aa9374
Autor
Minniti, D.
Saito, R.K.
Forster, F.
Pignata, G.
Ivanov, V.D.
Lucas, P.W.
Beamin, J.C.
Borissova, J.
Catelan, M.
Gonzalez, O.A.
Hempel, M.
Hsiao, E.
Kurtev, R.
Majaess, D.
Masetti, N.
Morrell, N.I.
Phillips, M.M.
Pullen, J.B.
Rejkuba, M.
Smith, L.
Surot, F.
Valenti, E.
Zoccali, M.
Institución
Resumen
We report the discovery of an enigmatic large-amplitude (ΔKs >10.5 mag) transient event in near-IR data obtained by the VISTA Variables in the Via Lactea (VVV) ESO Public Survey. The object (designated VVV-WIT- 06) is located at R.A.=17:07:18.917, decl.=-39:06:26.45 (J2000), corresponding to Galactic coordinates l=347.14539, b=0.88522. It exhibits a clear eruption, peaking at Ks=9 mag during 2013 July and fading to Ks ∼ 16.5 in 2017. Our late near-IR spectra show post-outburst emission lines, including some broad emission lines (upward of FWHM ∼ 3000 km s-1). We estimate a total extinction of AV = 10-15 mag in the surrounding field, and no progenitor was observed in ZYJHKs images obtained during 2010-2012 (down to Ks > 18.5mag). Subsequent deep near-IR imaging and spectroscopy, in concert with the available multiband photometry, indicate that VVV-WIT-06 may be either: (i) the closest Type I SN observed in about 400 years, (ii) an exotic highamplitude nova that would extend the known realm of such objects, or (iii) a stellar merger. In all of these cases, VVV-WIT-06 is a fascinating and curious astrophysical target under any of the scenarios considered.