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V1309 Sco Nova Scorpii 2008. Elena Mason, Robert Williams, Marcus Diaz ESO-Chile STCI IAG University of Sao Paulo. The FEROS nova survey. Jun 2003-Feb 2006 (ESO periods 71-76): 14 CNe; 2-12 epochs per object; La Silla 2.2+FEROS: λ -range ~400-900nm; R~48000 .
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V1309 ScoNova Scorpii 2008 Elena Mason, Robert Williams, Marcus Diaz ESO-Chile STCI IAG University of Sao Paulo
The FEROS nova survey Jun 2003-Feb 2006 (ESO periods 71-76): 14 CNe; 2-12 epochs per object; La Silla 2.2+FEROS: λ-range ~400-900nm; R~48000 [Williams et al. 2008, ApJ, 685, 451]
The THEA (Transient Heavy Elements Absorption) system • s-elements (Fe, Ti, Sc, V, Cr, Y, Sr, Zr) • low velocities (~500 km/s) • low dispersion velocities (35-300 km/s) • disappear ~1 month after the nova outburst • are external to the CN expanding ejecta
Discovery of V1309 Sco • narrow H emission lines (FWHM~670 & 300 km/s) • absorption lines • no P-Cyg absorption • SOAR spectrum at Cerro Pochon: • red continuum and colors: B=9.2 V=7.8 R=7.3 mag • pre-outburst mag ~14.8
ESO DDT at UT2+UVESdic1 436+580 & dic2 437+860 3000 – 10400 Aslit 0.7” & 1.0” R~70000 – 500005 epochs (Sep 13 to Oct 20)
singly ionized s-elements + FeI, CrI, … • low velocity (~-50 km/s with respect to systemic) • low dispersion velocities (FWHM~30 km/s)
__epoch 1, __ epoch 5 __ FeII (49) 5477.7 & FeI (15)5497.5
The Balmer lines: double peaked profile …absorption + emission narrow: emission ~140 km/s absorption ~ 70 km/s small relative velocity with respect to systemic (~50 km/s) “burst” at late epochs
Spectroscopic characteristics - summary: Absorption phase spectra (epochs 1-3): • Enormous amount of abs. lines from FeI, FeII, TiII, VII, ScII, SrII, YII, CrI, CrII, CaI, MnI and MgI • strong & narrow H Balmer in emission with complex profiles • continuum possibly consistent with a K type star Emission line phase spectra (epochs 4 & 5): • FeII, FeI, TiII etc. absorption lines now in emission • He I, OI, NI, [OI] • stronger H Balmer lines (by a factor up to a few 100s) • fainter but redder continuum • + [CaII] emission at 7291 & 7323 A
What is it? • cooler continuum • s-element absorption red nova (V838 Mon, V4332 Sgr …type) • narrow H emission • not a “classical” CN (spc. evolution & line velocities) • not an AGB or post-AGB (outburst amplitude) • not a symbiotic (giant at 13kpc toward the GC?) • not a born again AGB (spc evolution …) • ? • planet/stellar merging (Retter & Marom ‘03, Tylenda & Soker ‘06) • 50000 K Wolf Rayet “outburst” (Munari et al. ‘05) • CN on a low mass WD (Iben & Tutukov ‘92)
but …? V1309 Sco: red novae: Just Balmer emission lines emission which soon “turned off” A ≥ 9-10 mag • H + low & high ionization element emission lines • A~7 mag • how is it evolving?