The Early Spectrophotometric Evolution of V1186 Scorpii (Nova Scorpii 2004 #1)

Abstract

We report optical photometry and optical through mid-infrared spectroscopy of the classical nova V1186 Sco. This slowly developing nova had an complex light curve with multiple secondary peaks similar to those seen in PW Vul. The time to decline 2 magnitudes, t${}_2$, was 20 days but the erratic nature of the light curve makes determination of intrinsic properties based on the decline time (e.g., luminosity) problematic, and the often cited MMRD relationship of Della Valle and Livio (1995) fails to yield a plausible distance. Spectra covering 0.35 to 35 $\mu$m were obtained in two separate epochs during the first year of outburst. The first set of spectra, taken about 2 months after visible maximum, are typical of a CO-type nova with narrow line emission from \ion{H}{1}, \ion{Fe}{2}, \ion{O}{1} and \ion{He}{1}. Later data, obtained between 260 and 380 days after maximum, reveal an emerging nebular spectrum. \textit{Spitzer} spectra show weakening hydrogen recombination emission with the emergence of [\ion{Ne}{2}] (12.81 $\mu$m) as the strongest line. Strong emission from [\ion{Ne}{3}] (15.56 $\mu$m) is also detected. Photoionization models with low effective temperature sources and only marginal neon enhancement (Ne $\sim$ 1.3 Ne${}_{\odot }$) are consistent with these IR fine-structure neon lines indicating that V1186 Sco did not occur on a ONeMg white dwarf. In contrast, the slow and erratic light curve evolution, spectral development, and photoionization analysis of the ejecta imply the outburst occurred on a low mass CO white dwarf. We note that this is the first time strong [\ion{Ne}{2}] lines have been detected so early in the outburst of a CO nova and suggests that the presence of mid-infrared neon lines is not directly indicative of a ONeMg nova event.

arXiv comment7 figures, 37 pages. Astronimocal Journal accepted

References in corpus (7)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• The Spitzer Space Telescope Mission
• The Infrared Spectrograph on the Spitzer Space Telescope
• Nucleosynthesis in Classical Novae: ONe vs. CO White Dwarfs
• Optical Imaging of Nova Shells and the Maximum Magnitude-Rate of Decline Relationship
• Neon Abundances in B-Stars of the Orion Association: Solving the Solar Model Problem?
• Abundance analysis of the slow nova PW Vulpeculae 1984

Cited by in corpus (13)

• A Nova Outburst Powered by Shocks
• On Presolar Stardust Grains from CO Classical Novae
• Elemental Abundances in the Ejecta of Old Classical Novae from Late-Epoch Spitzer Spectra
• On the Rebrightenings of Classical Novae during the Early Phase
• Spectral Evolution of the Unusual Slow Nova V5558 Sgr
• U Sco 2010 outburst: observational evidence of an underlying ONeMg white dwarf
• Optical spectroscopic and polarization properties of 2011 outburst of the recurrent nova T Pyxidis
• Spectroscopic and geometrical evolution of the ejecta of the classical nova ASASSN-18fv
• The peculiar dust shell of Nova DZ Cru (2003)
• Photoionization modeling of the dusty nova V1280 Scorpii
• A WISE view of novae. I. The data
• Abundance analysis of the recurrent nova RS Ophiuchi (2006 outburst)
• Discovery and Detailed Study of the M31 Classical Nova AT 2023tkw: Evidence for Internal Shocks