A WIDELY SEPARATED, HIGHLY OCCLUDED COMPANION TO THE NEARBY LOW-MASS T TAURI STAR TWA 30
We report the discovery of TWA 30B, a wide (~3400 AU), co-moving M dwarf companion to the nearby (~42 pc) young star TWA 30. Companionship is confirmed from their statistically consistent proper motions and radial velocities (RVs), as well as a chance alignment probability of only 0.08%. Like TWA 30...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | en_US |
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Institute of Physics Publishing
2014
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| Online Access: | http://hdl.handle.net/1721.1/88273 |
| _version_ | 1826207103462670336 |
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| author | Looper, Dagny L. Bochanski, John J. Burgasser, Adam J. Mohanty, Subhanjoy Mamajek, Eric E. Faherty, Jacqueline K. West, Andrew A. Pitts, Mark A. |
| author2 | MIT Kavli Institute for Astrophysics and Space Research |
| author_facet | MIT Kavli Institute for Astrophysics and Space Research Looper, Dagny L. Bochanski, John J. Burgasser, Adam J. Mohanty, Subhanjoy Mamajek, Eric E. Faherty, Jacqueline K. West, Andrew A. Pitts, Mark A. |
| author_sort | Looper, Dagny L. |
| collection | MIT |
| description | We report the discovery of TWA 30B, a wide (~3400 AU), co-moving M dwarf companion to the nearby (~42 pc) young star TWA 30. Companionship is confirmed from their statistically consistent proper motions and radial velocities (RVs), as well as a chance alignment probability of only 0.08%. Like TWA 30A, the spectrum of TWA 30B shows signatures of an actively accreting disk (H I and alkali line emission) and forbidden emission lines tracing outflowing material ([O I], [O II], [O III], [S II], and [N II]). We have also detected [C I] emission in the optical data, marking the first such detection of this line in a pre-main-sequence star. Negligible RV shifts in the emission lines relative to the stellar frame of rest (ΔV lsim 30 km s–1) indicate that the outflows are viewed in the plane of the sky and that the corresponding circumstellar disk is viewed edge-on. Indeed, TWA 30B appears to be heavily obscured by its disk, given that it is 5 mag fainter than TWA 30A at K band despite having a slightly earlier spectral type (M4 versus M5). The near-infrared spectrum of TWA 30B also evinces an excess that varies on day timescales, with colors that follow classical T Tauri tracks as opposed to variable reddening (as is the case for TWA 30A). Multi-epoch data show this excess to be well modeled by a black body component with temperatures ranging from 630 to 880 K and emitting areas that scale inversely with the temperature. The variable excess may arise from disk structure such as a rim or a warp at the inner disk edge located at a radial distance of ~3-5 R ☉. As the second and third closest actively accreting and outflowing stars to the Sun (after TWA 3), TWA 30AB presents an ideal system for a detailed study of star and planetary formation processes at the low-mass end of the hydrogen-burning spectrum. |
| first_indexed | 2024-09-23T13:44:11Z |
| format | Article |
| id | mit-1721.1/88273 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T13:44:11Z |
| publishDate | 2014 |
| publisher | Institute of Physics Publishing |
| record_format | dspace |
| spelling | mit-1721.1/882732022-09-28T15:48:10Z A WIDELY SEPARATED, HIGHLY OCCLUDED COMPANION TO THE NEARBY LOW-MASS T TAURI STAR TWA 30 Looper, Dagny L. Bochanski, John J. Burgasser, Adam J. Mohanty, Subhanjoy Mamajek, Eric E. Faherty, Jacqueline K. West, Andrew A. Pitts, Mark A. MIT Kavli Institute for Astrophysics and Space Research Bochanski, John J. Burgasser, Adam J. We report the discovery of TWA 30B, a wide (~3400 AU), co-moving M dwarf companion to the nearby (~42 pc) young star TWA 30. Companionship is confirmed from their statistically consistent proper motions and radial velocities (RVs), as well as a chance alignment probability of only 0.08%. Like TWA 30A, the spectrum of TWA 30B shows signatures of an actively accreting disk (H I and alkali line emission) and forbidden emission lines tracing outflowing material ([O I], [O II], [O III], [S II], and [N II]). We have also detected [C I] emission in the optical data, marking the first such detection of this line in a pre-main-sequence star. Negligible RV shifts in the emission lines relative to the stellar frame of rest (ΔV lsim 30 km s–1) indicate that the outflows are viewed in the plane of the sky and that the corresponding circumstellar disk is viewed edge-on. Indeed, TWA 30B appears to be heavily obscured by its disk, given that it is 5 mag fainter than TWA 30A at K band despite having a slightly earlier spectral type (M4 versus M5). The near-infrared spectrum of TWA 30B also evinces an excess that varies on day timescales, with colors that follow classical T Tauri tracks as opposed to variable reddening (as is the case for TWA 30A). Multi-epoch data show this excess to be well modeled by a black body component with temperatures ranging from 630 to 880 K and emitting areas that scale inversely with the temperature. The variable excess may arise from disk structure such as a rim or a warp at the inner disk edge located at a radial distance of ~3-5 R ☉. As the second and third closest actively accreting and outflowing stars to the Sun (after TWA 3), TWA 30AB presents an ideal system for a detailed study of star and planetary formation processes at the low-mass end of the hydrogen-burning spectrum. George Herbig Toby Owen National Science Foundation (U.S.) United States. National Aeronautics and Space Administration 2014-07-11T16:36:01Z 2014-07-11T16:36:01Z 2010-11 2010-07 Article http://purl.org/eprint/type/JournalArticle 0004-6256 1538-3881 http://hdl.handle.net/1721.1/88273 Looper, Dagny L., John J. Bochanski, Adam J. Burgasser, Subhanjoy Mohanty, Eric E. Mamajek, Jacqueline K. Faherty, Andrew A. West, and Mark A. Pitts. “A WIDELY SEPARATED, HIGHLY OCCLUDED COMPANION TO THE NEARBY LOW-MASS T TAURI STAR TWA 30.” The Astronomical Journal 140, no. 5 (November 1, 2010): 1486–1499. en_US http://dx.doi.org/10.1088/0004-6256/140/5/1486 Astronomical Journal Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Institute of Physics Publishing arXiv |
| spellingShingle | Looper, Dagny L. Bochanski, John J. Burgasser, Adam J. Mohanty, Subhanjoy Mamajek, Eric E. Faherty, Jacqueline K. West, Andrew A. Pitts, Mark A. A WIDELY SEPARATED, HIGHLY OCCLUDED COMPANION TO THE NEARBY LOW-MASS T TAURI STAR TWA 30 |
| title | A WIDELY SEPARATED, HIGHLY OCCLUDED COMPANION TO THE NEARBY LOW-MASS T TAURI STAR TWA 30 |
| title_full | A WIDELY SEPARATED, HIGHLY OCCLUDED COMPANION TO THE NEARBY LOW-MASS T TAURI STAR TWA 30 |
| title_fullStr | A WIDELY SEPARATED, HIGHLY OCCLUDED COMPANION TO THE NEARBY LOW-MASS T TAURI STAR TWA 30 |
| title_full_unstemmed | A WIDELY SEPARATED, HIGHLY OCCLUDED COMPANION TO THE NEARBY LOW-MASS T TAURI STAR TWA 30 |
| title_short | A WIDELY SEPARATED, HIGHLY OCCLUDED COMPANION TO THE NEARBY LOW-MASS T TAURI STAR TWA 30 |
| title_sort | widely separated highly occluded companion to the nearby low mass t tauri star twa 30 |
| url | http://hdl.handle.net/1721.1/88273 |
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