PARALLACTIC MOTION FOR COMPANION DISCOVERY: AN M-DWARF ORBITING ALCOR
PARALLACTIC MOTION FOR COMPANION DISCOVERY: AN M-DWARF ORBITING ALCOR
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发现同伴的视差运动：绕轨道运行的 ALCOR
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
S. Hunt
中科院分区：
文献类型：
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作者：
N. Zimmerman;B. Oppenheimer;S. Hinkley;D. Brenner;I. Parry;A. Sivaramakrishnan;L. Hillenbrand;C. Beichman;J. Crepp;G. Vasisht;L. Roberts;R. Burruss;D. King;R. Soummer;R. Dekany;M. Shao;A. Bouchez;J. Roberts;S. Hunt
A5 V星星Alcor有一颗M3-M4矮伴星，这是一种新的天体测量技术所证明的。成像光谱学与自适应光学日冕照相术相结合，可以在J-和H-波段的1.6倍的对比度下检测和分光光度表征点源，与主星星星的距离为1“。使用天体测量光瞳平面网格，使我们能够在两个观测时期确定伴星和日冕遮蔽的主星星星之间的投影间隔，精度达到1.3万质量。我们的测量表明，在103天的过程中，共同的视差和自行，显着短于大多数同伴确认所需的时间，通过自行测量。这种普通视差方法可能比普通自行更严格，确保相邻物体处于相同的距离，而不是依赖于统计上的不可能性，即天空中两个彼此非常接近的物体沿同一方向移动。在一颗明亮的（V = 4.0等）附近（d= 25 pc）的星星周围发现一颗低质量（约0.25 M）伴星，突出了迄今为止尚未完全探测的双星星星参数空间区域。
The A5V star Alcor has an M3–M4 dwarf companion, as evidenced by a novel astrometric technique. Imaging spectroscopy combined with adaptive optics coronagraphy allowed for the detection and spectrophotometric characterization of the point source at a contrast of ∼6 J- and H-band magnitudes and separation of 1″ from the primary star. The use of an astrometric pupil plane grid allowed us to determine the projected separations between the companion and the coronagraphically occulted primary star to ⩽3 mas precision at two observation epochs. Our measurements demonstrate common parallactic and proper motion over the course of 103 days, significantly shorter than the period of time needed for most companion confirmations through proper motion measurements alone. This common parallax method is potentially more rigorous than common proper motion, ensuring that the neighboring bodies lie at the same distance, rather than relying on the statistical improbability that two objects in close proximity to each other on the sky move in the same direction. The discovery of a low-mass (∼0.25 M☉) companion around a bright (V = 4.0 mag), nearby (d= 25 pc) star highlights a region of binary star parameter space that to date has not been fully probed.