We present the Star cluster Hunting Pipeline (SHiP) which can identify star clusters in Gaia DR2 data, and establish a star cluster catalog for the Galactic disk. A Friend of Friend based cluster finder method is used to identify star clusters using 5-dimensional stellar parameters, l, b, ̟, µ α cos δ, and µ δ . Our new catalog contains 2443 star cluster candidates identified from disk stars located within |b| = 25 • and with G < 18 mag. An automatic isochrone fitting scheme is applied to all cluster candidates. With a combination of parameters obtained from isochrone fitting, we classify cluster candidates into three classes (Class 1, 2 and 3). Class 1 clusters are the most probable star cluster candidates with the most stringent criteria. Most of these clusters are nearby (within 4 kpc). Our catalog is crossmatched with three Galactic star cluster catalogs, Kharchenko et al. (2013), Cantat-Gaudin et al. (2018, 2019), and Bica et al. (2019. The proper motion and parallax of matched star clusters are in good agreement with these earlier catalogs. We discover 76 new star cluster candidates that are not listed in these 3 catalogs. The majority of these are clusters older than log(age/yr) = 8.0, and are located in the inner disk with |b| < 5 • . The recent discovery of new star clusters suggests that current Galactic star cluster catalogs are still incomplete. Among the Class 1 cluster candidates, we find 56 candidates for star cluster groups. The pipeline, the catalog and the member list containing all candidates star clusters and star cluster groups have been made publicly available.

We report the discovery of tidal structures around the intermediate-aged (∼ 700-800 Myr), nearby (∼ 85 pc) star cluster Coma Berenices. The spatial and kinematic grouping of stars is determined with the Gaia DR2 parallax and proper motion data, by a clustering analysis tool, StarGO, to map 5D parameters (X, Y, Z, µ α cos δ, µ δ ) onto a 2D neural network. A leading and a trailing tails, each with an extension of ∼ 50 pc are revealed for the first time around this disrupting star cluster. The cluster members, totaling to ∼ 115 +5 −3 M , are clearly mass segregated, and exhibit a flat mass function with α ∼ 0.79 ± 0.16, in the sense of dN/dm ∝ m −α , where N is the number of member stars and m is stellar mass, in the mass range of m = 0.25-2.51 M . Within the tidal radius of ∼6.9 pc, there are 77 member candidates with an average position, i.e., as the cluster center, of R.A.= 186.8110 deg, and decl.= 25.8112 deg, and an average distance of 85.8 pc. Additional 120 member candidates reside in the tidal structures, i.e., outnumbering those in the cluster core. The expansion of escaping members lead to an anisotropy in the velocity field of the tidal tails. Our analysis also serendipitously uncovers an adjacent stellar group, part of which has been cataloged in the literature. We identify 218 member candidates, 10 times more than previously known. This star group is some 65 pc away from, and ∼ 400 Myr younger than, Coma Ber, but is already at the final stage of disruption.