New Horizons in Time-Domain Astronomy Proceedings IAU Symposium No. 285, 2011 R.E.M. Grifin, R.J.. Hanisch & R. Seaman, eds. c  International Astronomical Union 2012 doi:10.1017/S174392131200124X A Global Robotic Telescope Network for Time-Domain Science R. A. Street 1 and T. A. Lister 1 , Y. Tsapras 1,2 , A. Shporer 1 , F. B. Bianco 1 , B. J. Fulton 1 , D. A. Howell 1 , B. Dilday 1 , M. Graham 1 , D. Sand 1 , J. Parent 1 , T. Brown 1 , K. Horne 3 , M. Dominik 3 †, P. Browne 3 , C. Snodgrass 4 , N. Kains 5 , D. Bramich 5 , N. Law 6 and I. Steele 7 1 LCOGT, 6740 Cortona Drive, Suite 102, Goleta, CA 93117, USA, email: rstreet@lcogt.net 2 School of Mathematical Sciences, Queen Mary College, London E1 4NS, UK 3 SUPA, School of Physics & Astronomy, University of St. Andrews, Fife, KY16 9SS, UK, 4 Max Planck Institute for Solar System Research, 37191 Katlenburg-Lindau, Germany 5 ESO, 85748 Garching bei M¨ unchen, Germany 6 Dept. of Astronomy and Astrophysics, University of Toronto, Ontario, M5S 3H4, Canada 7 Astrophysics Research Institute, Liverpool JMU, Birkenhead, CH41 1LD, UK. Abstract. Las Cumbres Observatory Global Telescope Network (LCOGT) is currently building a new kind of general-purpose astronomical facility: a fully robotic network of telescopes of 2m, 1m and 0.4m apertures and homogeneous instrumentation. A pan-network approach to scheduling (rather than per individual telescope) offers redundancy in the event of poor weather or technical failure, as well as the ability to observe a target around the clock. Here we describe the network design and instrumentation under development, together with the main science programmes already being lead by LCOGT staff. Keywords. telescopes, instrumentation: photometers, instrumentation: spectrographs,stars: plan- etary systems, stars: supernovae 1. Introduction At any given location, ground-based observations of time-domain phenomena suffer from gaps in their coverage caused by the diurnal cycle. The gaps can be supplemented with data from longitudinally-spaced sites, but at the cost of combining data from differ- ent instruments taken under very different conditions. While a number of such telescope networks like GONG and BiSON have been built to date, most have been designed for, and operated by, specific projects, with limited instrumentation. The Las Cumbres Ob- servatory Global Telescope Network (LCOGT) will be a new, general-purpose facility for optical/NIR photometry and spectroscopy, which we describe in Sections 2 & 3. Designed from the outset for time-domain astronomy, the main science drivers for LCOGT staff are exoplanet and supernova science; we highlight these programmes in Sections 4 & 5. 2. Robotic Observing Network Telescopes in the LCOGT network will be distributed longitudinally, at ∼6 sites in both hemispheres, making it possible to observe around the clock. All telescopes will † Royal Society University Research Fellow 408