J/A+A/578/A75 Spectrum of V4332 Sgr in 2005 (Tylenda+, 2015)
VLT/UVES spectroscopy of V4332 Sagittarii in 2005:
The best view on a decade-old stellar-merger remnant.
Tylenda R., Gorny S.K., Kaminski T., Schmidt M.
<Astron. Astrophys. 578, A75 (2015)>
=2015A&A...578A..75T 2015A&A...578A..75T
ADC_Keywords: Stars, peculiar ; Stars, late-type ; Spectroscopy
Keywords: stars: activity - circumstellar matter - stars: emission-line, Be -
stars: individual: V4332 Sgr - stars: late-type - stars: mass-loss
Abstract:
V4332 Sgr is a red transient (red nova) whose eruption was observed in
1994. The remnant of the eruption shows a unique optical spectrum:
strong emission lines of atomes and molecules superimposed on a M-type
stellar spectrum. The stellar-like remnant is presumably embedded in a
disc-like dusty envelope orientated almost face-on. The observed
optical spectrum is supposed to result from interactions of the
central-star radiation with dust and gas in the disc and outflows
initiated in 1994. We have reduced and measured a high-resolution
(R∼40000) spectrum of V4332 Sgr obtained with VLT/UVES in April/May
2005. The spectrum comes from the ESO archives and is the best quality
spectrum of the object ever obtained. We have identified and measured
over 200 emission features belonging to 11 elements and 6 molecules.
The continuous, stellar-like component can be classified as ∼M3. The
radial velocity of the object, as derived from narrow atomic emission
line, is -75km/s. The interstellar reddening was estimated as being
0.35<E(B-V)<0.75. From radial velocities of interstellar absorption
features in the NaI D lines we have estimated a lower limit of ∼5.5
kpc to the distance of V4332 Sgr. When compared to spectroscopic
observations done in 2009, the spectrum of V4332 Sgr considerably
evolved between 2005 and 2009. The object significantly faded in the
optical (by ∼2mag in the V band), which resulted from the main remnant
cooled by 300-350K corresponding to its spectral type changed from M3
to M5-6. The object however increased in luminosity by ∼50%, implying
a significant expansion of its dimensions. Most of the emission
features seen in 2005 significantly faded or even disappeared from the
spectrum of V4332 Sgr in 2009.
Description:
The spectrum of V4332 Sgr obtained with the Very Large Telescope's
UVES instrument in April/May 2005. The spectrum is calibrated to flux
units and corrected for telluric absorption features. The wavelength
scale is in the heliocentric rest frame.
Objects:
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RA (2000) DE Designation(s)
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18 50 36.70 -21 23 28.9 V4332 Sgr = NOVA Sgr 1994
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
spec.dat 32 170251 Spectrum of V4332 Sgr
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See also:
J/AZh/84/147 : Light curves of V838 Mon and V4332 Sgr (Goranskii+, 2007)
J/A+A/558/A82 : V4332 Sgr optical spectropolarimetry (Kaminski+, 2013)
Byte-by-byte Description of file: spec.dat
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Bytes Format Units Label Explanations
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1- 17 F17.11 0.1nm lambda [3759/10430] Wavelength in heliocentric
rest frame (Å)
20- 32 E13.9 8W/m2/nm Flux Observed absolute flux
(in 10-16erg/s/cm2/Å)
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Acknowledgements:
Romuald Tylenda, tylenda(at)ncac.torun.pl
Tomasz Kaminski, tkaminsk(at)eso.org
(End) Tomasz Kaminski [ESO, Santiago], Patricia Vannier [CDS] 31-Mar-2015