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Title: A coordinated X-ray and optical campaign of the nearest massive eclipsing binary, δ Orionis Aa. III. Analysis of optical photometric (MOST) and spectroscopic (ground-based) variations

Abstract

We report on both high-precision photometry from the Microvariability and Oscillations of Stars (MOST) space telescope and ground-based spectroscopy of the triple system δ Ori A, consisting of a binary O9.5II+early-B (Aa1 and Aa2) with P = 5.7 days, and a more distant tertiary (O9 IV P>400 years). This data was collected in concert with X-ray spectroscopy from the Chandra X-ray Observatory. Thanks to continuous coverage for three weeks, the MOST light curve reveals clear eclipses between Aa1 and Aa2 for the first time in non-phased data. From the spectroscopy, we have a well-constrained radial velocity (RV) curve of Aa1. While we are unable to recover RV variations of the secondary star, we are able to constrain several fundamental parameters of this system and determine an approximate mass of the primary using apsidal motion. We also detected second order modulations at 12 separate frequencies with spacings indicative of tidally influenced oscillations. These spacings have never been seen in a massive binary, making this system one of only a handful of such binaries that show evidence for tidally induced pulsations.

Authors:
; ;  [1];  [2];  [3];  [4];  [5];  [6];  [7];  [8];
  1. Département de physique and Centre de Recherche en Astrophysique du Québec (CRAQ), Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, Québec, H3C 3J7 (Canada)
  2. CRESST and X-ray Astrophysics Laboratory, NASA/GSFC, Greenbelt, MD 20771 (United States)
  3. Institut für Physik und Astronomie, Universität Potsdam, Karl-Liebknecht-Str. 24/25, D-14476, Potsdam (Germany)
  4. Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, 1900 La Plata, Buenos Aires (Argentina)
  5. TAPIR, Walter Burke Institute for Theoretical Physics, Mailcode 350-17, California Institute of Technology, Pasadena, CA 91125 (United States)
  6. FNRS Département AGO, Université de Liège, Allée du 6 Aout 17, Bat. B5C, 4000, Liège (Belgium)
  7. Department of Physics and Astronomy, University of Denver, 2112 East Wesley Avenue, Denver, CO 80208 (United States)
  8. Department of Physics and Astronomy, University of North Carolina at Greensboro, Greensboro, NC 27402-6170 (United States)
Publication Date:
OSTI Identifier:
22882756
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 809; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Since 2009, the country of publication for this journal is the UK.; Journal ID: ISSN 0004-637X
Country of Publication:
United Kingdom
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION SPECTROSCOPY; BINARY STARS; ECLIPSE; MASS TRANSFER; OSCILLATIONS; PHOTOMETRY; RADIAL VELOCITY; SPACE; STELLAR WINDS; TELESCOPES; X-RAY SPECTROSCOPY

Citation Formats

Pablo, Herbert, Richardson, Noel D., Moffat, Anthony F. J., Corcoran, Michael, Shenar, Tomer, Benvenuto, Omar, Fuller, Jim, Nazé, Yaël, Hoffman, Jennifer L., Miroshnichenko, Anatoly, Apellániz, Jesús Maíz, E-mail: hpablo@astro.umontreal.ca, and others, and. A coordinated X-ray and optical campaign of the nearest massive eclipsing binary, δ Orionis Aa. III. Analysis of optical photometric (MOST) and spectroscopic (ground-based) variations. United Kingdom: N. p., 2015. Web. doi:10.1088/0004-637X/809/2/134.
Pablo, Herbert, Richardson, Noel D., Moffat, Anthony F. J., Corcoran, Michael, Shenar, Tomer, Benvenuto, Omar, Fuller, Jim, Nazé, Yaël, Hoffman, Jennifer L., Miroshnichenko, Anatoly, Apellániz, Jesús Maíz, E-mail: hpablo@astro.umontreal.ca, & others, and. A coordinated X-ray and optical campaign of the nearest massive eclipsing binary, δ Orionis Aa. III. Analysis of optical photometric (MOST) and spectroscopic (ground-based) variations. United Kingdom. https://doi.org/10.1088/0004-637X/809/2/134
Pablo, Herbert, Richardson, Noel D., Moffat, Anthony F. J., Corcoran, Michael, Shenar, Tomer, Benvenuto, Omar, Fuller, Jim, Nazé, Yaël, Hoffman, Jennifer L., Miroshnichenko, Anatoly, Apellániz, Jesús Maíz, E-mail: hpablo@astro.umontreal.ca, and others, and. Thu . "A coordinated X-ray and optical campaign of the nearest massive eclipsing binary, δ Orionis Aa. III. Analysis of optical photometric (MOST) and spectroscopic (ground-based) variations". United Kingdom. https://doi.org/10.1088/0004-637X/809/2/134.
@article{osti_22882756,
title = {A coordinated X-ray and optical campaign of the nearest massive eclipsing binary, δ Orionis Aa. III. Analysis of optical photometric (MOST) and spectroscopic (ground-based) variations},
author = {Pablo, Herbert and Richardson, Noel D. and Moffat, Anthony F. J. and Corcoran, Michael and Shenar, Tomer and Benvenuto, Omar and Fuller, Jim and Nazé, Yaël and Hoffman, Jennifer L. and Miroshnichenko, Anatoly and Apellániz, Jesús Maíz, E-mail: hpablo@astro.umontreal.ca and others, and},
abstractNote = {We report on both high-precision photometry from the Microvariability and Oscillations of Stars (MOST) space telescope and ground-based spectroscopy of the triple system δ Ori A, consisting of a binary O9.5II+early-B (Aa1 and Aa2) with P = 5.7 days, and a more distant tertiary (O9 IV P>400 years). This data was collected in concert with X-ray spectroscopy from the Chandra X-ray Observatory. Thanks to continuous coverage for three weeks, the MOST light curve reveals clear eclipses between Aa1 and Aa2 for the first time in non-phased data. From the spectroscopy, we have a well-constrained radial velocity (RV) curve of Aa1. While we are unable to recover RV variations of the secondary star, we are able to constrain several fundamental parameters of this system and determine an approximate mass of the primary using apsidal motion. We also detected second order modulations at 12 separate frequencies with spacings indicative of tidally influenced oscillations. These spacings have never been seen in a massive binary, making this system one of only a handful of such binaries that show evidence for tidally induced pulsations.},
doi = {10.1088/0004-637X/809/2/134},
url = {https://www.osti.gov/biblio/22882756}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 809,
place = {United Kingdom},
year = {2015},
month = {8}
}