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arXiv 0909.4306astro-ph.EP
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用Keck自适应光学对β Pic内行星候选者的轨道约束

Orbital Constraints on the beta Pic Inner Planet Candidate with Keck Adaptive Optics

Michael P. Fitzgerald, Paul Kalas, James R. Graham

摘要:

一个点源在2003年的L'(3.8微米)图像中被观测到8 AU的投影,最近被认为是一个行星候选者。在这里,我们展示了2008年在凯克天文台获得的L '波段自适应光学成像的结果。我们没有检测到β Pic b超过0.29弧秒的极限半径,或5.5 AU的投影,从恒星。如果β Pic b是一颗绕轨道运行的行星,那么在两个观测时期之间的五年内,它已经移动了>=0.12角秒(投影2.4天文单位)接近恒星。我们研究的轨道参数的范围与观测结果一致,包括可能的边界从以前推断的星子带的位置。我们发现一个家庭的低偏心率轨道与半长轴~8-9 AU是完全允许的,以及广泛的区域的轨道与e<~0.2,a>~10 AU是允许的,如果在2003年的行星的视运动是对恒星。我们比较这个允许的空间与预测的行星轨道要素的文献。此外,我们还展示了在未来几年内类似的观测如何进一步限制允许轨道的空间。如果在2013年之前没有探测到这个来源,那么就不能将其解释为一颗在6.4和16 AU微行星带之间运行的行星。

英文摘要:

A point source observed 8 AU in projection from beta Pictoris in L' (3.8 micron) imaging in 2003 has been recently presented as a planet candidate. Here we show the results of L'-band adaptive optics imaging obtained at Keck Observatory in 2008. We do not detect beta Pic b beyond a limiting radius of 0.29 arcsec, or 5.5 AU in projection, from the star. If beta Pic b is an orbiting planet, then it has moved >=0.12 arcsec (2.4 AU in projection) closer to the star in the five years separating the two epochs of observation. We examine the range of orbital parameters consistent with the observations, including likely bounds from the locations of previously inferred planetesimal belts. We find a family of low-eccentricity orbits with semimajor axes ~8-9 AU that are completely allowed, as well as a broad region of orbits with e<~0.2, a>~10 AU that are allowed if the apparent motion of the planet was towards the star in 2003. We compare this allowed space with predictions of the planetary orbital elements from the literature. Additionally, we show how similar observations in the next several years can further constrain the space of allowed orbits. Non-detections of the source through 2013 will exclude the interpretation of the candidate as a planet orbiting between the 6.4 and 16 AU planetesimal belts.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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