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Limits on eclipses of the pre-main-sequence star KH 15D in the first half of the 20th century

Joshua N. Winn·Peter M. Garnavich·K. Z. Stanek·Dimitar D. Sasselov
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Abstract

Over the last decade, the pre-main sequence star KH 15D has exhibited periodic eclipses that are surprisingly deep (~3 mag) and long-lasting (~40% of the 48.4-day period). The cause of the eclipses is unknown, but it could be a feature in a nearly edge-on protoplanetary disk. Here we report on an analysis of archival photographs of KH 15D from the Harvard College Observatory plate collection, most of which were taken during the years 1913-1951. During this time range, the data are consistent with no eclipses; the duty cycle of 1 mag eclipses was less than 20%. The decadal timescale of this change in eclipse behavior is compatible with the expected timescale of protoplanet/disk interactions. Archival images from more recent epochs should reveal the onset of the eclipses.

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Joshua N. Winn, Peter M. Garnavich, K. Z. Stanek, Dimitar D. Sasselov. 2003-06-25. Limits on eclipses of the pre-main-sequence star KH 15D in the first half of the 20th century. https://doi.org/10.1086/378314

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