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Title: PREDICTING GAIA’S PARALLAX DISTANCE TO THE CYGNUS OB2 ASSOCIATION WITH ECLIPSING BINARIES

Abstract

The Cygnus OB2 Association is one of the nearest and largest collections of massive stars in the Galaxy. Situated at the heart of the “Cygnus X” complex of star-forming regions and molecular clouds, its distance has proven elusive owing to the ambiguous nature of kinematic distances along this ℓ ≃ 80° sightline and the heavy, patchy extinction. In an effort to refine the three-dimensional geometry of key Cygnus X constituents, we have measured distances to four eclipsing double-lined OB-type spectroscopic binaries that are probable members of Cyg OB2. We find distances of 1.33 ± 0.17, 1.32 ± 0.07, 1.44 ± 0.18, and 1.32 ± 0.13 kpc toward MT91 372, MT91 696, CPR2002 A36, and Schulte 3, respectively. We adopt a weighted average distance of 1.33 ± 0.06 kpc. This agrees well with spectrophotometric estimates for the Association as a whole and with parallax measurements of protostellar masers in the surrounding interstellar clouds, thereby linking the ongoing star formation in these clouds with Cyg OB2. We also identify Schulte 3C (O9.5V), a 4″ visual companion to the 4.75 day binary Schulte 3(A+B), as a previously unrecognized Association member.

Authors:
 [1]; ; ; ;  [2]
  1. Dept. of Astronomy, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States)
  2. Dept. of Physics and Astronomy, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82070 (United States)
Publication Date:
OSTI Identifier:
22525366
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 811; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION SPECTROSCOPY; CLOUDS; DISTANCE; ECLIPSE; EMISSION SPECTROSCOPY; GALAXIES; MASERS; PROTOSTARS; RADIAL VELOCITY; SPECTROPHOTOMETRY; STAR CLUSTERS; STAR EVOLUTION; STARS; THREE-DIMENSIONAL CALCULATIONS

Citation Formats

Kiminki, Daniel C., Kobulnicky, Henry A., Álvarez, Carlos A. Vargas, Alexander, Michael J., and Lundquist, Michael J., E-mail: kiminki@email.arizona.edu. PREDICTING GAIA’S PARALLAX DISTANCE TO THE CYGNUS OB2 ASSOCIATION WITH ECLIPSING BINARIES. United States: N. p., 2015. Web. doi:10.1088/0004-637X/811/2/85.
Kiminki, Daniel C., Kobulnicky, Henry A., Álvarez, Carlos A. Vargas, Alexander, Michael J., & Lundquist, Michael J., E-mail: kiminki@email.arizona.edu. PREDICTING GAIA’S PARALLAX DISTANCE TO THE CYGNUS OB2 ASSOCIATION WITH ECLIPSING BINARIES. United States. doi:10.1088/0004-637X/811/2/85.
Kiminki, Daniel C., Kobulnicky, Henry A., Álvarez, Carlos A. Vargas, Alexander, Michael J., and Lundquist, Michael J., E-mail: kiminki@email.arizona.edu. Thu . "PREDICTING GAIA’S PARALLAX DISTANCE TO THE CYGNUS OB2 ASSOCIATION WITH ECLIPSING BINARIES". United States. doi:10.1088/0004-637X/811/2/85.
@article{osti_22525366,
title = {PREDICTING GAIA’S PARALLAX DISTANCE TO THE CYGNUS OB2 ASSOCIATION WITH ECLIPSING BINARIES},
author = {Kiminki, Daniel C. and Kobulnicky, Henry A. and Álvarez, Carlos A. Vargas and Alexander, Michael J. and Lundquist, Michael J., E-mail: kiminki@email.arizona.edu},
abstractNote = {The Cygnus OB2 Association is one of the nearest and largest collections of massive stars in the Galaxy. Situated at the heart of the “Cygnus X” complex of star-forming regions and molecular clouds, its distance has proven elusive owing to the ambiguous nature of kinematic distances along this ℓ ≃ 80° sightline and the heavy, patchy extinction. In an effort to refine the three-dimensional geometry of key Cygnus X constituents, we have measured distances to four eclipsing double-lined OB-type spectroscopic binaries that are probable members of Cyg OB2. We find distances of 1.33 ± 0.17, 1.32 ± 0.07, 1.44 ± 0.18, and 1.32 ± 0.13 kpc toward MT91 372, MT91 696, CPR2002 A36, and Schulte 3, respectively. We adopt a weighted average distance of 1.33 ± 0.06 kpc. This agrees well with spectrophotometric estimates for the Association as a whole and with parallax measurements of protostellar masers in the surrounding interstellar clouds, thereby linking the ongoing star formation in these clouds with Cyg OB2. We also identify Schulte 3C (O9.5V), a 4″ visual companion to the 4.75 day binary Schulte 3(A+B), as a previously unrecognized Association member.},
doi = {10.1088/0004-637X/811/2/85},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 811,
place = {United States},
year = {2015},
month = {10}
}