We present relative astrometric and photometric measurements of visual binaries made in 2011–2012, with PISCO2 installed at the 76-cm refractor of Côte d'Azur Observatory in Nice (France). Our observing list contains orbital couples as well as binaries whose motion is still uncertain. Three different techniques have been used for obtaining those measurements: Lucky imaging, speckle interferometry, and the direct vector autocorrelation method. From our observations of 3,136 multiple stars, we obtained 3,568 new measurements with angular separations in the range of 0″.1–10″ and an average accuracy of 0″.016. The mean error on the position angles is 1°.7. Most of the position angles were determined without the usual 180° ambiguity with the application of the direct vector autocorrelation technique and/or by inspection of the Lucky images or the long integration files. We managed to routinely monitor faint systems (m_V ≈ 9–11) with large magnitude difference (up to Δm_V ≈ 5). We have thus been able to measure many systems containing red dwarf stars that had been poorly monitored since their discovery. We also measured the magnitude difference of the two components of 326 binaries with an estimated error of 0.2 mag. Except for a few objects that have been discussed, our measurements are in a good agreement with the ephemerides computed with published orbital elements, even for the binaries closer than the diffraction limit. Thanks to good seeing images and with the use of high-contrast numerical filters, we have also been able to obtain 196 measurements with an angular separation smaller than the diffraction limit of our instrumentation, and consistent with those obtained with larger telescopes. We also obtained new measurements of the 15th magnitude multiple system CON37, and discovered a faint new double star in its vicinity. Finally, we report 47 measurements of 28 new binaries found during our observations.

中文翻译：

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2011-2012 年在 Nice 76-cm 折射仪上使用 PISCO2 测量视觉双星

我们展示了 2011-2012 年视觉双星的相对天体测量和光度测量，PISCO2 安装在尼斯（法国）蔚蓝海岸天文台的 76 厘米折射镜上。我们的观测列表包含轨道偶以及运动仍不确定的双星。三种不同的技术已被用于获得这些测量值：幸运成像、散斑干涉测量和直接矢量自相关方法。从我们对 3,136 颗多星的观测中，我们获得了 3,568 次新的测量值，角间距在 0 ″ .1-10 ″范围内，平均精度为 0 ″.016。位置角度的平均误差为 1°.7。大多数位置角是通过应用直接矢量自相关技术和/或通过检查 Lucky 图像或长积分文件来确定的，没有通常的 180° 模糊。我们设法定期监测微弱系统（米_V  ≈9-11）具有大幅度差（最高Δ米_V ≈ 5)。因此，我们能够测量许多包含自发现以来监测不佳的红矮星的系统。我们还测量了 326 个双星的两个分量的幅度差异，估计误差为 0.2 mag。除了已经讨论过的一些天体，我们的测量结果与使用已发表轨道元素计算的星历非常吻合，即使对于比衍射极限更近的双星也是如此。由于良好的视觉图像和高对比度数值滤波器的使用，我们还能够获得 196 次测量，其角度间隔小于我们仪器的衍射极限，并且与使用更大望远镜获得的测量结果一致。我们还获得了 15 等多系统 CON37 的新测量结果，并在其附近发现了一颗微弱的新双星。最后，我们报告了在我们的观察中发现的 28 个新双星的 47 个测量值。