We present a deep (50 hours exposed) image of the nearby spiral galaxy M 63 (NGC 5055), taken with a 0.14-m aperture telescope. The galaxy halo exhibits the known very faint system of stellar streams extending across 110 kpc. We found 5 very low-surface-brightness dwarf galaxies around M 63. Assuming they are satellites of M 63, their median parameters are: absolute $B$-magnitude -8.8 mag, linear diameter 1.3 kpc, surface brightness $\sim$ 27.8 mag/sq. arcsec and linear projected separation 93 kpc. Based on four brighter satellites with measured radial velocities, we derived a low orbital mass estimate of M 63 to be (5.1$\pm$1.8) 10$^{11} M_{\odot}$ on a scale of $\sim$216 kpc. The specific property of M 63 is its declining rotation curve. Taking into account the declining rotation curves of the M 63 and three nearby massive galaxies NGC 2683, NGC 2903, NGC 3521, we recognize their low mean orbital mass-to-K-band luminosity ratio, (4.8$\pm$1.1) $M_{\odot}/L_{\odot}$, that is only $\sim$1/6 of the corresponding ratio for the Milky Way and M 31.

中文翻译：

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围绕卷曲螺旋星系 M 63 的新矮人

我们展示了附近螺旋星系 M 63 (NGC 5055) 的深度（曝光 50 小时）图像，使用 0.14 米孔径望远镜拍摄。星系晕展示了已知的非常微弱的恒星流系统，其延伸范围为 110 kpc。我们在 M 63 周围发现了 5 个表面亮度极低的矮星系。假设它们是 M 63 的卫星，它们的中值参数为：绝对 $B$-magnitude -8.8 mag，线性直径 1.3 kpc，表面亮度 $\sim$ 27.8马格/平方米 arcsec 和线性投影间隔 93 kpc。基于测量径向速度的四颗更亮的卫星，我们得出 M 63 的低轨道质量估计为 (5.1$\pm$1.8) 10$^{11} M_{\odot}$，尺度为 $\sim$216 kpc . M 63 的特性是它的下降旋转曲线。考虑到 M 63 和附近三个大质量星系 NGC 2683 的自转下降曲线，