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Optical Spectroscopy of the IR Source CPM 19 and Surrounding Objects

T. Yu. Magakian, T. A. Movsessian, A. V. Moiseev, T. S. Molyarova, R. I. Uklein

Abstract

Optical spectra of the well-known infrared source CPM~19, which exhibited a strong decline in brightness during the period from 1984--1987 to 2000--2005, have been obtained for the first time. A strong and broad H$α$ emission line has been detected, along with the possible presence of [S II] emission. No traces of an absorption spectrum are observed. It is suggested that the optical component of CPM 19 is in the pre-main-sequence stage. Various explanations of the observed properties are considered; a plausible scenario is that CPM 19 may belong to the class of UX Ori-type stars with an unusually long eclipse duration, similar to that observed in V1184 Tau. Spectra of other nebulous objects in the vicinity of CPM 19, including the HH objects HH 940 and HH 941, have also been obtained and discussed.

Optical Spectroscopy of the IR Source CPM 19 and Surrounding Objects

Abstract

Optical spectra of the well-known infrared source CPM~19, which exhibited a strong decline in brightness during the period from 1984--1987 to 2000--2005, have been obtained for the first time. A strong and broad H emission line has been detected, along with the possible presence of [S II] emission. No traces of an absorption spectrum are observed. It is suggested that the optical component of CPM 19 is in the pre-main-sequence stage. Various explanations of the observed properties are considered; a plausible scenario is that CPM 19 may belong to the class of UX Ori-type stars with an unusually long eclipse duration, similar to that observed in V1184 Tau. Spectra of other nebulous objects in the vicinity of CPM 19, including the HH objects HH 940 and HH 941, have also been obtained and discussed.
Paper Structure (10 sections, 4 figures)

This paper contains 10 sections, 4 figures.

Table of Contents

  1. Introduction
  2. Observations
  3. Results
  4. Photometry of CPM 19
  5. Spectroscopy of CPM 19
  6. Spectra of Other Emission Objects
  7. HH 940
  8. GM 2-4
  9. HH 941A and HH 941B
  10. Discussion and conclusion

Figures (4)

  • Figure 1: Pan-STARRS r-band image of the studied region, showing the positions of the spectrograph slits and the observed objects. Slit 1 corresponds to the observations of December 17, 2022, and slit 2 to those of March 15, 2023.
  • Figure 2: Position-velocity (PV) diagram of CPM 19 and HH 940 in the regions of the H$\alpha$ and [N II] lines (left) and the [S II] $\lambda$6717 Å and $\lambda$6730 Å lines (right). The near-complete absence of these emission features in the region between CPM 19 and HH 940 is clearly evident, especially in the H$\alpha$ line.
  • Figure 3: Position-velocity (PV) diagram of the spectra of GM 2-4 (center) and HH 941A (bottom) in the region of the H$\alpha$ and [N II] lines. The high positive radial velocity of the H$\alpha$ emission in the spectrum of the nebula is clearly seen, as well as the nearly constant velocity of this emission along the direction from HH 941A toward GM 2-4.
  • Figure 4: Position-velocity (PV) diagram of the spectra of GM 2-4 (top) and HH 941B (bottom) in the region of the H$\alpha$ line. The high positive radial velocity of the H$\alpha$ emission in the spectrum of the nebula is clearly visible, as well as the rapid increase in the absolute velocity of this emission toward HH 941B (cf. Fig.\ref{['GM2-4']}).