NEW BVIC PHOTOMETRY OF LOW-MASS PLEIADES STARS: EXPLORING THE EFFECTS OF ROTATION ON BROADBAND COLORS
NEW BVIC PHOTOMETRY OF LOW-MASS PLEIADES STARS: EXPLORING THE EFFECTS OF ROTATION ON BROADBAND COLORS
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DOI：
10.1088/0004-6256/148/2/30
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发表时间：
2014-06
期刊：
影响因子：
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通讯作者：
B. Kamai;F. Vrba;J. Stauffer;K. Stassun
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文献类型：
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作者：
B. Kamai;F. Vrba;J. Stauffer;K. Stassun
本文对350个9 < V <$17的昴星团自行成员进行了新的BVIC测光。重要的是，我们的新目录包括大量的K型和早期M型恒星，在这个基准星团中，经过良好校准的约翰逊/费因斯测光的低质量恒星数量大约增加了一倍。我们结合联合收割机我们的新的测光与现有的测光从文献中定义一个纯粹的经验等时线在昴星团年龄（100亿年），从V = 9延伸到17。我们使用经验等时线，以确定48个新的可能的二进制和14个可能的非成员。通过光度测定确定的单颗恒星与它们在色星等图（CMD）中的预期位置进行比较。在1亿年前，K中期和M早期的恒星被预测位于零龄主序星（ZAMS）之上，尚未到达ZAMS。我们发现在B − V与V CMD的关系中，K中矮星和M早期矮星被移到ZAMS下方（或蓝向）。使用恒星先前报告的自转周期，我们发现自转周期和CMD位移之间存在高度统计显著的相关性，在这个意义上，自转更快的恒星在B − V CMD中具有最大的位移。
We present new BVIC photometry for 350 Pleiades proper motion members with 9 < V ≲ 17. Importantly, our new catalog includes a large number of K- and early M-type stars, roughly doubling the number of low-mass stars with well-calibrated Johnson/Cousins photometry in this benchmark cluster. We combine our new photometry with existing photometry from the literature to define a purely empirical isochrone at Pleiades age (≈100 Myr) extending from V = 9 to 17. We use the empirical isochrone to identify 48 new probable binaries and 14 likely nonmembers. The photometrically identified single stars are compared against their expected positions in the color–magnitude diagram (CMD). At 100 Myr, the mid K and early M stars are predicted to lie above the zero-age main sequence (ZAMS) having not yet reached the ZAMS. We find in the B − V versus V CMD that mid K and early M dwarfs are instead displaced below (or blueward of) the ZAMS. Using the stars' previously reported rotation periods, we find a highly statistically significant correlation between rotation period and CMD displacement, in the sense that the more rapidly rotating stars have the largest displacements in the B − V CMD.