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B[e]-star CI Cam: a high-resolution spectrum atlas in the range of 395$÷$780 nm

Valentina G. Klochkova, Anatoly S. Miroshnichenko, Victoria N. Komarova, Nonna S. Tavolzhanskaya

TL;DR

This study presents a high-resolution optical spectrum atlas of the B[e] star CI Cam, obtained with the 6-m BTA telescope and NES, covering 395–780 nm at R≥60,000. The atlas comprises 59 echelle-order fragments and ~400 identified features, dominated by H I, He I, Fe II, and [Fe II] emission with distinctive two-peak profiles, including rare [V II], [Cr II], and [Ni II] lines, formed in an optically thin circumstellar envelope. It confirms CI Cam as a B[e] supergiant and yields a systemic velocity around -55 km s-1 with minimal variability, while noting a lack of wind-type P Cygni profiles and the absence of certain Ca II and [O I] features. The work provides a crucial reference for future spectroscopic monitoring of CI Cam and similar evolved, mass-losing hot stars, and informs models of their circumstellar disks and envelopes.

Abstract

The atlas of the spectrum of the B[e] star CI Cam obtained with the 6-meter BTA telescope in combination with the NES spectrograph in the wavelength interval of 395$÷$780 nm with a resolution of $λ/Δλ\ge60\,000$ is presented. The atlas contains about 400 spectral features and illustrates the diversity of spectral features of the unique star, forming in a complex circumstellar environment. The spectrum is dominated by forceful single-peaked HI, HeI emissions and numerous double-peaked permitted and forbidden emissions of ions of chemical elements starting from the CNO triad up to metals (Mg, Al, Ti, V, Cr, Fe) with practically ``rectangular'' profiles. The FeII and [FeII] emissions predominate in the spectrum. However, several other double-peaked forbidden ion emissions were also detected: [VII], [Cr II], [Ni II]. The atlas is presented graphically, with a separate figure corresponding to each echelle order. A list of identified lines, including a number of known interstellar features is presented in table form. CI Cam supergiant status has been confirmed.

B[e]-star CI Cam: a high-resolution spectrum atlas in the range of 395$÷$780 nm

TL;DR

This study presents a high-resolution optical spectrum atlas of the B[e] star CI Cam, obtained with the 6-m BTA telescope and NES, covering 395–780 nm at R≥60,000. The atlas comprises 59 echelle-order fragments and ~400 identified features, dominated by H I, He I, Fe II, and [Fe II] emission with distinctive two-peak profiles, including rare [V II], [Cr II], and [Ni II] lines, formed in an optically thin circumstellar envelope. It confirms CI Cam as a B[e] supergiant and yields a systemic velocity around -55 km s-1 with minimal variability, while noting a lack of wind-type P Cygni profiles and the absence of certain Ca II and [O I] features. The work provides a crucial reference for future spectroscopic monitoring of CI Cam and similar evolved, mass-losing hot stars, and informs models of their circumstellar disks and envelopes.

Abstract

The atlas of the spectrum of the B[e] star CI Cam obtained with the 6-meter BTA telescope in combination with the NES spectrograph in the wavelength interval of 395780 nm with a resolution of is presented. The atlas contains about 400 spectral features and illustrates the diversity of spectral features of the unique star, forming in a complex circumstellar environment. The spectrum is dominated by forceful single-peaked HI, HeI emissions and numerous double-peaked permitted and forbidden emissions of ions of chemical elements starting from the CNO triad up to metals (Mg, Al, Ti, V, Cr, Fe) with practically ``rectangular'' profiles. The FeII and [FeII] emissions predominate in the spectrum. However, several other double-peaked forbidden ion emissions were also detected: [VII], [Cr II], [Ni II]. The atlas is presented graphically, with a separate figure corresponding to each echelle order. A list of identified lines, including a number of known interstellar features is presented in table form. CI Cam supergiant status has been confirmed.

Paper Structure

This paper contains 4 sections, 28 figures.

Table of Contents

  1. INTRODUCTION
  2. OBSERVATIONS AND SPECTRUM REDUCTION
  3. THE ATLAS AND A LIST OF IDENTIFIED LINES
  4. MAIN RESULTS

Figures (28)

  • Figure 1: The profiles of selected emissions in the spectrum obtained on September 3, 2015. The position of the vertical corresponds to a systemic velocity of $V_{\rm sys}=-55.4$ km s$^{-1}$.
  • Figure 1: CI Cam spectrum: fragments 1--2.
  • Figure 1: CI Cam spectrum: fragments 3--5.
  • Figure 1: CI Cam spectrum: fragments 6--8.
  • Figure 1: CI Cam spectrum: fragments 9--11.
  • ...and 23 more figures