LUMINOSITY DISCREPANCY IN THE EQUAL-MASS, PRE-MAIN-SEQUENCE ECLIPSING BINARY PAR 1802: NON-COEVALITY OR TIDAL HEATING?
Parenago 1802, a member of the ~1 Myr Orion Nebula Cluster, is a double-lined, detached eclipsing binary in a 4.674 day orbit, with equal-mass components ([M subscript 2] [over M subscript 1] = 0.985 ± 0.029). Here we present extensive VI[subscript C] JHK [subscript S] light curves (LCs) spanning ~1...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | en_US |
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IOP Publishing
2015
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| Online Access: | http://hdl.handle.net/1721.1/95618 |
| _version_ | 1826190171162279936 |
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| author | Gómez Maqueo Chew, Yilen Prša, Andrej Stempels, Eric Hebb, Leslie Barnes, Rory Heller, René Mathieu, Robert D. Stassun, Keivan |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Gómez Maqueo Chew, Yilen Prša, Andrej Stempels, Eric Hebb, Leslie Barnes, Rory Heller, René Mathieu, Robert D. Stassun, Keivan |
| author_sort | Gómez Maqueo Chew, Yilen |
| collection | MIT |
| description | Parenago 1802, a member of the ~1 Myr Orion Nebula Cluster, is a double-lined, detached eclipsing binary in a 4.674 day orbit, with equal-mass components ([M subscript 2] [over M subscript 1] = 0.985 ± 0.029). Here we present extensive VI[subscript C] JHK [subscript S] light curves (LCs) spanning ~15 yr, as well as a Keck/High Resolution Echelle Spectrometer (HIRES) optical spectrum. The LCs evince a third light source that is variable with a period of 0.73 days, and is also manifested in the high-resolution spectrum, strongly indicating the presence of a third star in the system, probably a rapidly rotating Classical T Tauri star. We incorporate this third light into our radial velocity and LC modeling of the eclipsing pair, measuring accurate masses (M [subscript 1] = 0.391 ± 0.032 and M [subscript 2] = 0.385 ± 0.032 M [subscript ☉]), radii (R [subscript 1] = 1.73 ± 0.02 and R [subscript 2] = 1.62 ± 0.02 R [subscript ☉]), and temperature ratio (T [subscript eff, 1] [over T [subscript eff, 2]] = 1.0924 ± 0.0017). Thus, the radii of the eclipsing stars differ by 6.9% ± 0.8%, the temperatures differ by 9.2% ± 0.2%, and consequently the luminosities differ by 62% ± 3%, despite having masses equal to within 3%. This could be indicative of an age difference of ~3 × 10[superscript 5] yr between the two eclipsing stars, perhaps a vestige of the binary formation history. We find that the eclipsing pair is in an orbit that has not yet fully circularized, e = 0.0166 ± 0.003. In addition, we measure the rotation rate of the eclipsing stars to be 4.629 ± 0.006 days; they rotate slightly faster than their 4.674 day orbit. The non-zero eccentricity and super-synchronous rotation suggest that the eclipsing pair should be tidally interacting, so we calculate the tidal history of the system according to different tidal evolution theories. We find that tidal heating effects can explain the observed luminosity difference of the eclipsing pair, providing an alternative to the previously suggested age difference. |
| first_indexed | 2024-09-23T08:36:10Z |
| format | Article |
| id | mit-1721.1/95618 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T08:36:10Z |
| publishDate | 2015 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/956182022-09-30T09:51:39Z LUMINOSITY DISCREPANCY IN THE EQUAL-MASS, PRE-MAIN-SEQUENCE ECLIPSING BINARY PAR 1802: NON-COEVALITY OR TIDAL HEATING? Gómez Maqueo Chew, Yilen Prša, Andrej Stempels, Eric Hebb, Leslie Barnes, Rory Heller, René Mathieu, Robert D. Stassun, Keivan Massachusetts Institute of Technology. Department of Physics Stassun, Keivan Parenago 1802, a member of the ~1 Myr Orion Nebula Cluster, is a double-lined, detached eclipsing binary in a 4.674 day orbit, with equal-mass components ([M subscript 2] [over M subscript 1] = 0.985 ± 0.029). Here we present extensive VI[subscript C] JHK [subscript S] light curves (LCs) spanning ~15 yr, as well as a Keck/High Resolution Echelle Spectrometer (HIRES) optical spectrum. The LCs evince a third light source that is variable with a period of 0.73 days, and is also manifested in the high-resolution spectrum, strongly indicating the presence of a third star in the system, probably a rapidly rotating Classical T Tauri star. We incorporate this third light into our radial velocity and LC modeling of the eclipsing pair, measuring accurate masses (M [subscript 1] = 0.391 ± 0.032 and M [subscript 2] = 0.385 ± 0.032 M [subscript ☉]), radii (R [subscript 1] = 1.73 ± 0.02 and R [subscript 2] = 1.62 ± 0.02 R [subscript ☉]), and temperature ratio (T [subscript eff, 1] [over T [subscript eff, 2]] = 1.0924 ± 0.0017). Thus, the radii of the eclipsing stars differ by 6.9% ± 0.8%, the temperatures differ by 9.2% ± 0.2%, and consequently the luminosities differ by 62% ± 3%, despite having masses equal to within 3%. This could be indicative of an age difference of ~3 × 10[superscript 5] yr between the two eclipsing stars, perhaps a vestige of the binary formation history. We find that the eclipsing pair is in an orbit that has not yet fully circularized, e = 0.0166 ± 0.003. In addition, we measure the rotation rate of the eclipsing stars to be 4.629 ± 0.006 days; they rotate slightly faster than their 4.674 day orbit. The non-zero eccentricity and super-synchronous rotation suggest that the eclipsing pair should be tidally interacting, so we calculate the tidal history of the system according to different tidal evolution theories. We find that tidal heating effects can explain the observed luminosity difference of the eclipsing pair, providing an alternative to the previously suggested age difference. National Science Foundation (U.S.) (Grant AST-0349075) National Science Foundation (U.S.) (Grant AST-1009810) W. M. Keck Foundation 2015-02-25T17:18:54Z 2015-02-25T17:18:54Z 2011-12 2011-06 Article http://purl.org/eprint/type/JournalArticle 0004-637X 1538-4357 http://hdl.handle.net/1721.1/95618 Gómez Maqueo Chew, Yilen, Keivan G. Stassun, Andrej Prša, Eric Stempels, Leslie Hebb, Rory Barnes, René Heller, and Robert D. Mathieu. “LUMINOSITY DISCREPANCY IN THE EQUAL-MASS, PRE-MAIN-SEQUENCE ECLIPSING BINARY PAR 1802: NON-COEVALITY OR TIDAL HEATING?” The Astrophysical Journal 745, no. 1 (December 29, 2011): 58. © 2012 The American Astronomical Society en_US http://dx.doi.org/10.1088/0004-637x/745/1/58 Astrophysical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf IOP Publishing American Astronomical Society |
| spellingShingle | Gómez Maqueo Chew, Yilen Prša, Andrej Stempels, Eric Hebb, Leslie Barnes, Rory Heller, René Mathieu, Robert D. Stassun, Keivan LUMINOSITY DISCREPANCY IN THE EQUAL-MASS, PRE-MAIN-SEQUENCE ECLIPSING BINARY PAR 1802: NON-COEVALITY OR TIDAL HEATING? |
| title | LUMINOSITY DISCREPANCY IN THE EQUAL-MASS, PRE-MAIN-SEQUENCE ECLIPSING BINARY PAR 1802: NON-COEVALITY OR TIDAL HEATING? |
| title_full | LUMINOSITY DISCREPANCY IN THE EQUAL-MASS, PRE-MAIN-SEQUENCE ECLIPSING BINARY PAR 1802: NON-COEVALITY OR TIDAL HEATING? |
| title_fullStr | LUMINOSITY DISCREPANCY IN THE EQUAL-MASS, PRE-MAIN-SEQUENCE ECLIPSING BINARY PAR 1802: NON-COEVALITY OR TIDAL HEATING? |
| title_full_unstemmed | LUMINOSITY DISCREPANCY IN THE EQUAL-MASS, PRE-MAIN-SEQUENCE ECLIPSING BINARY PAR 1802: NON-COEVALITY OR TIDAL HEATING? |
| title_short | LUMINOSITY DISCREPANCY IN THE EQUAL-MASS, PRE-MAIN-SEQUENCE ECLIPSING BINARY PAR 1802: NON-COEVALITY OR TIDAL HEATING? |
| title_sort | luminosity discrepancy in the equal mass pre main sequence eclipsing binary par 1802 non coevality or tidal heating |
| url | http://hdl.handle.net/1721.1/95618 |
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