NEAR-INFRARED VARIABILITY IN THE ORION NEBULA CLUSTER
NEAR-INFRARED VARIABILITY IN THE ORION NEBULA CLUSTER
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DOI：
10.1088/0004-6256/150/4/132
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发表时间：
2015-05
期刊：
影响因子：
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通讯作者：
T. Rice;B. Reipurth;S. Wolk;L. Vaz;Nicholas Cross
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作者：
T. Rice;B. Reipurth;S. Wolk;L. Vaz;Nicholas Cross
利用莫纳克亚山上的UKIRT，我们对几乎一平方度的恒星形成猎户座星云团进行了一次新的近红外J，H，K监测调查，在三个观测季节的120个夜晚进行了观测，总共跨越了894天。我们监测了15,000颗恒星，直到J 20？使用WFCAM仪器，并从我们的数据中提取了1203颗显着变星。通过研究H-K，K色星等图中的年轻恒星（YSO）的变化，我们能够区分变化的物理机制。许多变量显示颜色行为，表明尘埃灭绝或磁盘/吸积活动，但我们发现，当监测较长的时间，一些恒星在这两个变化机制之间转移。此外，我们表明，在年轻的恒星盘/吸积变化的内在时间尺度比尘埃灭绝的变化。我们证实，变异幅度是统计相关的进化类在所有波段和颜色。对这1203个变星的研究发现，73个周期性的AA Tau型变星，许多是大振幅和长周期的（P > 15？>包括三颗显示出与环双星盘活动一致的间隔很广的周期性增亮事件的恒星，以及四颗新的食双星。这些现象和其他现象表明，在年轻恒星中发生的长期盘/吸积变率过程的活动。我们已经在线提供了这1203个变量的光变曲线和相关数据。
Using UKIRT on Mauna Kea, we have carried out a new near-infrared J, H, K monitoring survey of almost a square degree of the star-forming Orion Nebula Cluster with observations on 120 nights over three observing seasons, spanning a total of 894 days. We monitored ∼15,000 stars down to J ≈ 20 ?> using the WFCAM instrument, and have extracted 1203 significantly variable stars from our data. By studying variability in young stellar objects (YSOs) in the H – K, K color–magnitude diagram, we are able to distinguish between physical mechanisms of variability. Many variables show color behavior indicating either dust-extinction or disk/accretion activity, but we find that when monitored for longer periods of time, a number of stars shift between these two variability mechanisms. Further, we show that the intrinsic timescale of disk/accretion variability in young stars is longer than that of dust-extinction variability. We confirm that variability amplitude is statistically correlated with evolutionary class in all bands and colors. Our investigations of these 1203 variables have revealed 73 periodic AA Tau type variables, many large-amplitude and long-period ( P > 15 ?> days) YSOs, including three stars showing widely spaced periodic brightening events consistent with circumbinary disk activity, and four new eclipsing binaries. These phenomena and others indicate the activity of long-term disk/accretion variability processes taking place in young stars. We have made the light curves and associated data for these 1203 variables available online.