著者

伊藤 綾香

出版者

法政大学大学院理工学・工学研究科

雑誌

法政大学大学院紀要. 理工学・工学研究科編 = 法政大学大学院紀要. 理工学・工学研究科編 (ISSN:21879923)

巻号頁・発行日

vol.58, 2017-03-31

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We examined the properties of 45 variable stars in the Trapezium cluster, which we identified from J, H and Ks band near-infrared imaging with the 1.4 m IRSF telescope carried out at three epochs, 2000, 2005, and 2014.Their positions in the color-magnitude diagram and the two-color diagram show that they are young stellar objects. The variability over 2000 to 2014 of the majority of them (36/45) are found to be classified into two patterns. One group became brighter and bluer while the other became fainter and redder. Stars with largerbrightness change showed larger color change with the time scale of 〜10 years. The distribution of slope angles in the J vs J-H diagrams of 2014 is similar to that of 2005 showing the bimodal feature consistent with previous work. Comparison of the slope angles with that of interstellar extinction suggests that the origin of variation ofabout two-thirds of the 45 variables is the change in the column density of material similar to that responsible for the interstellar extinction. The light variation of the remaining variables may be due to the change in accretion and circumstellar disk activity.Key Words : young stars, variable stars, infrared, open clusters, Orion, Trapezium cluster