UBVI photometry of Melotte 66

Multiple generations of stars are routinely encountered in globular clusters, but no convincing evidence has been found in Galactic open clusters up to date. In this paper we...球状星团（globular clusters）中普遍观测到多代恒星的存在，但迄今为止，在银河系疏散星团（Galactic open clusters）中尚未发现令人信服的证据。在本文中，我们...