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Title: LOCATING THE TRAILING EDGE OF THE CIRCUMBINARY RING IN THE KH 15D SYSTEM

Abstract

Following two years of complete occultation of both stars in the binary T Tauri star KH 15D by its opaque circumbinary ring, KH 15D has abruptly brightened again during apastron phases, reaching I = 15 mag. Here, we show that the brightening is accompanied by a change in spectral class from K6/K7 (the spectral class of star A) to {approx}K1, and a bluing of the system in V - I by about 0.3 mag. A radial velocity measurement confirms that, at apastron, we are now seeing direct light from star B, which is more luminous and of earlier spectral class than star A. Evidently, the trailing edge of the occulting screen has just become tangent to one anse of star B's projected orbit. This confirms a prediction of the precession models, supports the view that the tilted ring is self-gravitating, and ushers in a new era of the system's evolution that should be accompanied by the same kind of dramatic phenomena observed from 1995 to 2009. It also promotes KH 15D from a single-lined to a double-lined eclipsing binary, greatly enhancing its value for testing pre-main-sequence models. The results of our study strengthen the case for truncation of the outermore » ring at around 4 AU by a sub-stellar object such as an extremely young giant planet. The system is currently at an optimal configuration for detecting the putative planet and we urge expedient follow-up observations.« less

Authors:
;  [1];  [2];  [3];  [4]
  1. Astronomy Department, Wesleyan University, Middletown, CT 06459 (United States)
  2. Gemini Observatory, Northern Operations Center, 670 N. A'ohoku Place, Hilo, HI 96720 (United States)
  3. Department of Physics and Astronomy, Dickinson College, Carlisle, PA 17013 (United States)
  4. Department of Astrophysics, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States)
Publication Date:
OSTI Identifier:
22078530
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 757; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ECLIPSE; ORBITS; PLANETS; PRECESSION; RADIAL VELOCITY; STAR EVOLUTION; T TAURI STARS; VISIBLE RADIATION

Citation Formats

Capelo, Holly L., Herbst, William, Leggett, S. K., Hamilton, Catrina M., and Johnson, John A. LOCATING THE TRAILING EDGE OF THE CIRCUMBINARY RING IN THE KH 15D SYSTEM. United States: N. p., 2012. Web. doi:10.1088/2041-8205/757/1/L18.
Capelo, Holly L., Herbst, William, Leggett, S. K., Hamilton, Catrina M., & Johnson, John A. LOCATING THE TRAILING EDGE OF THE CIRCUMBINARY RING IN THE KH 15D SYSTEM. United States. doi:10.1088/2041-8205/757/1/L18.
Capelo, Holly L., Herbst, William, Leggett, S. K., Hamilton, Catrina M., and Johnson, John A. Thu . "LOCATING THE TRAILING EDGE OF THE CIRCUMBINARY RING IN THE KH 15D SYSTEM". United States. doi:10.1088/2041-8205/757/1/L18.
@article{osti_22078530,
title = {LOCATING THE TRAILING EDGE OF THE CIRCUMBINARY RING IN THE KH 15D SYSTEM},
author = {Capelo, Holly L. and Herbst, William and Leggett, S. K. and Hamilton, Catrina M. and Johnson, John A.},
abstractNote = {Following two years of complete occultation of both stars in the binary T Tauri star KH 15D by its opaque circumbinary ring, KH 15D has abruptly brightened again during apastron phases, reaching I = 15 mag. Here, we show that the brightening is accompanied by a change in spectral class from K6/K7 (the spectral class of star A) to {approx}K1, and a bluing of the system in V - I by about 0.3 mag. A radial velocity measurement confirms that, at apastron, we are now seeing direct light from star B, which is more luminous and of earlier spectral class than star A. Evidently, the trailing edge of the occulting screen has just become tangent to one anse of star B's projected orbit. This confirms a prediction of the precession models, supports the view that the tilted ring is self-gravitating, and ushers in a new era of the system's evolution that should be accompanied by the same kind of dramatic phenomena observed from 1995 to 2009. It also promotes KH 15D from a single-lined to a double-lined eclipsing binary, greatly enhancing its value for testing pre-main-sequence models. The results of our study strengthen the case for truncation of the outer ring at around 4 AU by a sub-stellar object such as an extremely young giant planet. The system is currently at an optimal configuration for detecting the putative planet and we urge expedient follow-up observations.},
doi = {10.1088/2041-8205/757/1/L18},
journal = {Astrophysical Journal Letters},
number = 1,
volume = 757,
place = {United States},
year = {Thu Sep 20 00:00:00 EDT 2012},
month = {Thu Sep 20 00:00:00 EDT 2012}
}