DISCOVERY OF Hα EMISSION FROM THE CLOSE COMPANION INSIDE THE GAP OF TRANSITIONAL DISK HD 142527
DISCOVERY OF Hα EMISSION FROM THE CLOSE COMPANION INSIDE THE GAP OF TRANSITIONAL DISK HD 142527
复制标题
过渡盘 HD 142527 间隙内紧密伴星的 Hα 发射的发现
DOI：
10.1088/2041-8205/781/2/l30
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
R. Briguglio
中科院分区：
文献类型：
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作者：
L. Close;K. Follette;J. Males;A. Puglisi;M. Xompero;D. Apai;J. Najita;A. Weinberger;K. Morzinski;T. Rodigas;P. Hinz;V. Bailey;R. Briguglio
我们利用新型高阶 585 执行器麦哲伦自适应光学系统 (MagAO)，通过 MagAO 的 VisAO 科学相机获得了 HD 142527 的超高分辨率可见光图像。在 6.5 m 麦哲伦望远镜 (0.″5−0.″7) 的中值视宁条件下，我们发现 MagAO 在 Hα (0.656 μm) 处提供 24%–19% 的斯特列尔。我们在距离恒星仅 86.3 ± 1.9 mas (∼12 AU) 处检测到嵌入在这个年轻的过渡盘系统中的微弱伴星 (HD 142527B)。在 Hα 和连续谱滤波器中均检测到伴星（Hα 处的 Δmag = 6.33 ± 0.20 mag，连续谱滤波器中的 Δmag = 7.50 ± 0.25 mag）。这证实了 Biller 及其同事在 8 m 甚大望远镜上通过稀疏孔径掩蔽发现的暂定伴星。来自~0.25太阳质量伴星（EW = 180 Å）的Hα发射意味着质量吸积率为~5.9 × 10−10 Msun yr−1，总吸积光度为1.2% Lsun。假设吸积率相似，我们估计，对于一系列光消光（3.4-0 mag），一颗 1 木星质量的气态巨行星在 Hα 处的行星/恒星对比度可能比 H 波段（COND 模型）好得多（50-1000×）。我们认为，~0.5–5 Mjup 处于气体吸积阶段的太阳系外行星在 Hα 处的亮度可能比在近红外处的亮度高得多。这就是我们对太阳系外行星进行新的 MagAO GAPplanetS 调查的动机。
We utilized the new high-order 585 actuator Magellan Adaptive Optics system (MagAO) to obtain very high-resolution visible light images of HD 142527 with MagAO's VisAO science camera. In the median seeing conditions of the 6.5 m Magellan telescope (0.″5−0.″7), we find MagAO delivers 24%–19% Strehl at Hα (0.656 μm). We detect a faint companion (HD 142527B) embedded in this young transitional disk system at just 86.3 ± 1.9 mas (∼12 AU) from the star. The companion is detected in both Hα and a continuum filter (Δmag = 6.33 ± 0.20 mag at Hα and 7.50 ± 0.25 mag in the continuum filter). This provides confirmation of the tentative companion discovered by Biller and co-workers with sparse aperture masking at the 8 m Very Large Telescope. The Hα emission from the ∼0.25 solar mass companion (EW = 180 Å) implies a mass accretion rate of ∼5.9 × 10−10 Msun yr−1 and a total accretion luminosity of 1.2% Lsun. Assuming a similar accretion rate, we estimate that a 1 Jupiter mass gas giant could have considerably better (50–1000×) planet/star contrasts at Hα than at the H band (COND models) for a range of optical extinctions (3.4–0 mag). We suggest that ∼0.5–5 Mjup extrasolar planets in their gas accretion phase could be much more luminous at Hα than in the NIR. This is the motivation for our new MagAO GAPplanetS survey for extrasolar planets.