SYMBIOTIC STAR RS OPHIUCHI

The page monitor the 2006 outburst of RS Oph (cf. IAUC 4030, 4031) - see IAUC 8671.
The star shows 5 recorded outbursts with irregular frequency: 1898, 1933, 1958, 1967, and 1985.
Position: R.A. = 17h50m13.530s, Decl. = -06°42'30.60'' (equinox 2000.0)

February 14.209 UT 2006 Observation (at V magnitude near 5.0)

Observatory: Castanet Tolosan (France) - IAU959
Observer: Christian Buil
Instrument: Celestron 11 telescope (0.28 m diameter) - LHIRES3 spectrograph with a 2400 g/mm grating (sampling of 0.115 A/pixel) + Audine KAF-0402ME CCD. Three individual spectra are associated for cover a wide spectral range.

Spectrum normalized at the wavelength 6450 A - telluric lines are not removed:


Detail of the Ha emission:



Detail of possible P Cygnii near H-alpha (the faint emission line at 6457 A is real):


Comparison of the RS spectrum and the Vega spectrum (Alpha Lyr) taken the same night for calibration purpose:


The profile show a broad emission line of H-alpha. The FWHM of the broad emission is 3930 km/s. The total width of the H-alpha line (at the base) is 7540 km/s. A narrow and intense double-peaked structure of  H-alpha is also observed, with a red and bleu separation of 84 km/s. The intensity of the principal peak is 11.7 time the local continuum.

A possible explanation about the two major features of the H-alpha spectral profile, derived from literature. The RS Oph is composed by a white dwarf (the primary component) orbiting in the wind of red giant (the secondary component of spectral class M0 III / M2 III). The eruptions are driven by the accretion of a stream from the red giant on to the white dwarf star (the outbursts may be generated by an instability in the cool companion or by a disk instability). During outburst, the very broad H-alpha line component is produced by emission from high-velocity ejecta (velocities of order 4000 km/s). The narrow-line component is produced in the portion of the red giant wind ionized by the UV pulse from the explosion and/or radiation from the shock produced by the passage of the ejecta through the wind or a pre-outburst enveloppe.

February 25.22 UT 2006 Observation (at V magnitude near 7.0)

Observatory: Castanet Tolosan (France) - IAU959
Observer: Christian Buil
Instrument: Celestron 11 telescope (0.28 m diameter) -LHIRES3 spectrograph with a 600 g/mm grating (sampling of 0.74 A/pixel) + Audine KAF-0401ME CCD. Four individual spectra are associated for cover the spectral range. Exposure time: 6563 A region 8x300 s, 5890 A region 7x300 s, 5200 A region  5x300 s, 4860 A region 4x300 s.

Spectrum normalized at the wavelength 6100 A and rectified for the instrumental response - telluric lines are not removed:

The full observed range:

  

Details:

 


 

Comparison of the Feb. 14 (0.11 A/pixel) and Feb. 25 (0.74 A/pixel) spectra (normalized at the same wavelength):


Equivalent Width (EW) the February 25: EW = 2100 Angstroms.

February 28.17 UT 2006 Observation (at V magnitude near 7.2)

Observatory: Castanet Tolosan (France) - IAU959
Observer: Christian Buil
Instrument: Celestron 11 telescope (0.28 m diameter) -LHIRES3 spectrograph with a 600 g/mm grating (sampling of 0.74 A/pixel) + Audine KAF-0402ME CCD. Three individual spectra are assembled for cover the actual spectral range. Exposure time: 5x300 s.

The full observed range:



Details:





The H-alpha and HeI 5876 A, HeI 6678 and HeI 7066 dominate the covered spectral range.

Comparison of the Feb. 25 and Feb. 28 spectra:

 

March 13.181 UT 2006 Observation (at V magnitude near 9.0)

Observatory: Castanet Tolosan (France) - IAU959
Observer: Christian Buil
Instrument: Celestron 11 telescope (0.28 m diameter) - LHIRES3 spectrograph with a 150 g/mm grating (sampling of 2.99 A/pixel) + Audine KAF-0402ME CCD. Three individual spectra are assembled for cover the actual spectral range. Exposure time: 8x120 s. Normalized at wavelength 5600 A and rectified for the instrumental response.


2D spectrum. Artificially colored.

March 15.124 UT 2006 Observation (at V magnitude near 9.0)

Observatory: Castanet Tolosan (France) - IAU959
Observer: Christian Buil
Instrument: Celestron 11 telescope (0.28 m diameter) - LHIRES3 spectrograph with a 2400 g/mm grating (sampling of 0.115 A/pixel) + Audine KAF-0402ME CCD. Exposure time: 16x300 s. Normalized with the aim of the March 13 observation. H2O telluric lines are removed.

 The setup used (morning of 14 February 2006):

Download

14/02/2006 spectrum
25/02/2006 spectrum
28/02/2006 spectrum
13/03/2006 spectrum
15/03/2006 spectrum

August 15.824 UT 2010 Observation (at V magnitude near 11.0)

Observatory: OHP
Observer: Christian Buil
Instrument: Celestron 9 telescope (0.235 m diameter) - LISA spectrograph (R=620) + QSI583 CCD camera. Exposure time: 7x600 s.
Donwload spectrum: _rsoph_20100815_825.dat



March 23.102, 2011 Observation

Observatory: Castanet-Tolosan
Observer: Christian Buil
Instrument: Celestron 11 telescope (0.280 m diameter) - LISA spectrograph (R=600) + QSI583 CCD camera. Exposure time: 5x600 s.
Donwload spectrum: _rsoph_20110323_102.dat 


August 4.960, 2011 Observation

Observatory: OHP
Observer: Christian Buil
Instrument: Celestron 9 telescope (0.235 m diameter) - LISA spectrograph (R=750) + QSI583 CCD camera. Exposure time: 5x600 s.
Donwload spectrum: _rsoph_20110804_960.dat 


June 26.925, 2012 Observation

Observatory: Castanet-Tolosan
Observer: Christian Buil
Instrument: Celestron 11 telescope (0.28 m diameter) - LISA spectrograph (R=1000) + Atik314L+ CCD camera. Exposure time: 7x300 s.
Donwload spectrum: _rsoph_20120626_925.fit 


April 3.126, 2013 Observation

Observatory: Castanet-Tolosan
Observer: Christian Buil
Instrument: CN212 (0.212 m diameter) - Alpy 600 spectrograph (R=600) + Atik460EX+ CCD camera. Exposure time: 4x600 s.
Donwload spectrum: _rsoph_20130403_126_cbuil.fit 


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