An unusual very low-mass high-amplitude pre-main sequence periodic variable
An unusual very low-mass high-amplitude pre-main sequence periodic variable
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一个不寻常的极低质量高振幅前主序周期变量
DOI：
10.1051/0004-6361/201118649
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发表时间：
2012
影响因子：
6.5
通讯作者：
Herbst
中科院分区：
文献类型：
--
作者：
Rodriguez-Ledesma;Ibrahimov;Messina;Parihar;Hessman;Alves de Oliveira;Herbst
AimsWe已经调查了CHS 7797，一个不寻常的周期性变量在猎户座Nebula Cluster. MethodsAn extensiveI波段光度数据集CHS 7797的变化的性质之间编译2004 - 2010使用各种望远镜。在Randz ′波段收集了进一步的光学数据。结果CHS 7797在R、I和z ′波段出现了异常的大振幅变化，振幅为1.7mag，周期为17.786 ± 0.03d（FAP = 1 × 10 - 15%）。亮度调制的幅度在较长波长处仅略微减小。这颗星星在周期的102/3期间是暗淡的，七个不同观测季节的相位光变曲线的形状显示出微小的变化和小幅度的变化。有趣的是，对于λ = 2 μ m，没有显着的颜色通量相关性，而当在较长波长下变暗时，物体会变得更红。CHS 7797的光谱类型为M 6，估计质量在0.04 - 0.1 M之间。结论数据分析表明，CHS 7797的周期性变化很可能是由轨道运动引起的。由于在光学中缺乏任何颜色-亮度相关性，因此排除了由热点引起的旋转亮度调制的可变性。后者表明CHS 7797很可能是被星周物质遮蔽的，这些物质中的颗粒尺寸从典型的0.1 μ m增长到101 - 2 μ m。我们讨论了两种可能的情况下，CHS 7797是周期性的结构在一个光盘，即CHS 7797是一个单一的对象与拱盘，或CHS 7797是一个二进制系统，类似于KH 15 D，其中倾斜的拱盘是负责的变化。讨论了在给定相位下I波段典型的0.3等变化的可能原因。
AimsWe have investigated the nature of the variability of CHS 7797, an unusual periodic variable in the Orion Nebula Cluster.MethodsAn extensiveI-band photometric data set of CHS 7797 was compiled between 2004−2010 using various telescopes. Further optical data have been collected inRandz′ bands. In addition, simultaneous observations of the ONC region including CHS 7797 were performed in theI,J,Ks& IRAC 3.6 and 4.5μm bands over a time interval of ≈40 d.ResultsCHS 7797 shows an unusual large-amplitude variation of ≈1.7 mag in theR,I, andz′ bands with a period 17.786 ± 0.03 d (FAP= 1 × 10-15%). The amplitude of the brightness modulation decreases only slightly at longer wavelengths. The star is faint during ≈2/3 of the period and the shape of the phased light-curves for the seven different observing seasons shows minor changes and small-amplitude variations. Interestingly, there are no significant colour-flux correlations forλ≲ 2μm, while the object becomes redder when fainter at longer wavelengths. CHS 7797 has a spectral type of M 6 and an estimated mass between 0.04−0.1M⊙.ConclusionsThe analysis of the data suggests that the periodic variability of CHS 7797 is most probably caused by an orbital motion. Variability as a result of rotational brightness modulation by a hot spot is excluded by the lack of any colour-brightness correlation in the optical. The latter indicates that CHS 7797 is most probably occulted by circumstellar matter in which grains have grown from typical 0.1μm to ≈1−2μm sizes. We discuss two possible scenarios in which CHS 7797 is periodically eclipsed by structures in a disc, namely that CHS 7797 is a single object with a circumstellar disc, or that CHS 7797 is a binary system, similar to KH 15D, in which an inclined circumbinary disc is responsible of the variability. Possible reasons for the typical 0.3 mag variations inI-band at a given phase are discussed.
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影响因子：
64.8
作者：
W. Herbst;C. Hamilton;Katherine LeDuc;J. Winn;C. Johns–Krull;R. Mundt;M. Ibrahimov
通讯作者：
M. Ibrahimov
不寻常的前主序星 V718 Persei (HMW 15) - 整个日食的光度测量和光谱学
DOI：
--
发表时间：
2008
期刊：
影响因子：
--
作者：
V. Grinin;H. C. Stempels;G. Gahm;S. Sergeev;A. Arkharov;O. Barsunova;L. Tambovtseva
通讯作者：
L. Tambovtseva
KH 15D 的轨道和掩星
DOI：
10.1086/503417
发表时间：
2006
期刊：
The Astrophysical Journal
影响因子：
--
作者：
J. Winn;C. Hamilton;William J. Herbst;Jennifer L. Hoffman;M. Holman;John A. Johnson;Marc J. Kuchner
通讯作者：
Marc J. Kuchner
DOI：
--
发表时间：
2006
期刊：
影响因子：
--
作者：
Leonie Kampe;Johannes Zimmermann;D. Bender;E. Caligor;A. Borowski;J. Ehrenthal;Cord Benecke;Susanne Hörz
通讯作者：
Susanne Hörz
DOI：
10.1086/307902
发表时间：
1999-05
期刊：
The Astrophysical Journal
影响因子：
--
作者：
K. Luhman;K. Luhman
通讯作者：
K. Luhman;K. Luhman