Target of Opportunity Observations of Gravitational Wave Events with LSST

The discovery of the electromagnetic counterparts to the binary neutron star merger GW170817 has opened the era of GW+EM multi-messenger astronomy. Exploiting this breakthrough requires increasing samples to explore the diversity of kilonova behaviour and provide more stringent constraints on the Hubble constant, and tests of fundamental physics. LSST can play a key role in this field in the 2020s, when the gravitational wave detector network is expected to detect higher rates of merger events involving neutron stars ($\sim$10s per year) out to distances of several hundred Mpc. Here we propose comprehensive target-of-opportunity (ToOs) strategies for follow-up of gravitational-wave sources that will make LSST the premiere machine for discovery and early characterization for neutron star mergers and other gravitational-wave sources.Comment: White paper for LSST cadence optimization- ToO

Multisite CCD Photometry of

. The results of a two-site observing campaign of the open cluster NGC 6134 are presented. The observations mainly consist of time series differential CCD photometry with a Johnson V-filter over a period of 10 days. Six, maybe seven, ffi Scuti stars are present in the cluster. Modes have been identified in six stars, and up to 5 modes have been found in a single star. No secure mode identification can be made yet due to lack of sufficient data for the stars, but some ideas about the nature of the modes can be obtained by utilizing the fact that all the variables belong to the same open cluster. Key words: stars: ffi Scuti stars - Blue stragglers - evolution of - oscillations of - clusters: open - photometry 1. Introduction Open clusters are of great importance for testing theories of stellar evolution. They are also very important in the study of pulsating stars as they provide constraints on the luminosities and ages of such stars which are cluster members. Mode identification then ..