The Disappearing Act of KH 15D: Photometric Results from 1995 to 2004

Abstract

We present results from the most recent (2002-2004) observing campaigns of the eclipsing system KH 15D, in addition to re-reduced data obtained at Van Vleck Observatory (VVO) between 1995 and 2000. Phasing nine years of photometric data shows substantial evolution in the width and depth of the eclipses. The most recent data indicate that the eclipses are now approximately 24 days in length, or half the orbital period. These results are interpreted and discussed in the context of the recent models for this system put forward by Winn et al. and Chiang & Murray-Clay. A periodogram of the entire data set yields a highly significant peak at 48.37 +/- 0.01 days, which is in accord with the spectroscopic period of 48.38 +/- 0.01 days determined by Johnson et al. Another significant peak, at 9.6 days, was found in the periodogram of the out-of-eclipse data at two different epochs. We interpret this as the rotation period of the visible star and argue that it may be tidally locked in pseudosynchronism with its orbital motion. If so, application of Hut's theory implies that the eccentricity of the orbit is e = 0.65 +/- 0.01. Analysis of the UVES/VLT spectra obtained by Hamilton et al. shows that the v sin(i) of the visible star in this system is 6.9 +/- 0.3 km/sec. Using this value of v sin(i) and the measured rotation period of the star, we calculate the lower limit on the radius to be R = (1.3 +/- 0.1), R_Sun, which concurs with the value obtained by Hamilton et al. from its luminosity and effective temperature. Here we assume that i = 90 degrees since it is likely that the spin and orbital angular momenta vectors are nearly aligned.

55 pages, 18 figures, 1 color figure, to appear the September issue of the Astronomical Journal

References in corpus (15)

• A rotational and variability study of a large sample of PMS stars in NGC 2264
• The Circumbinary Ring of KH 15D
• The Katzman Automatic Imaging Telescope Gamma-Ray Burst Alert System, and Observations of GRB 020813
• KH 15D: Gradual Occultation of a Pre-Main-Sequence Binary
• Eclipses by a Circumstellar Dust Feature in the Pre-Main Sequence Star KH15D
• Fine Structure in the Circumstellar Environment of a Young, Solar-like Star: the Unique Eclipses of KH 15D
• KH 15D: A Spectroscopic Binary
• The History of the Mysterious Eclipses of KH 15D: Asiago Observatory, 1967-1982
• Natural Coronagraphic Observations of the Eclipsing T Tauri System KH 15D: Evidence for Accretion and Bipolar Outflow in a WTTS
• Spectropolarimetry and Modeling of the Eclipsing T Tauri Star KH 15D
• Limits on eclipses of the pre-main-sequence star KH 15D in the first half of the 20th century
• KH15D: a star eclipsed by a large scale dusty vortex?
• Spectroscopy of Molecular Hydrogen Emission from KH 15D
• H${}_2$ Emission Nebulosity Associated with KH 15D
• The History of the Mysterious Eclipses of KH 15D II. Asiago, Kiso, Kitt Peak, Mt. Wilson, Palomar, Tautenburg and Rozhen Observatories, 1954-97

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