The start of ePESSTO - a new 2 year Large Programme at the NTT

A new phase in the evolution of PESSTO has started. The “extended” Public ESO Spectroscopic Survey of Transient objects was approved as a 2 year Large Programme by the ESO OPC starting in April 2017. From Period 99 we were approved to continue our spectroscopic survey as ePESSTO. The operational mode of around 10N per month over 9 - 10 lunations during the year will continue and we will continue to provide immediate public classifications and classification spectra through Astronomer’s Telegrams, the IAU Transient Name Server and WiSeREP.

The scientific focus of ePESSTO has been adjusted to focus on the most exciting new transient populations being discovered. We are especially focused on the interesting area of nuclear transients, and understanding what causes the diverse range of high luminosity variations at the cores of galaxies. These include tidal disruption events, very luminous circum-nuclear supernovae and blue hyper-variables. Superluminous supernovae are still a major focus along with unusual transients situated far (tens of kiloparsecs) from their host galaxies. Gamma ray bursts and transients associated with high energy or radio detections and non-photonic triggers will also be a major line of investigation. With the discovery of gravitational waves by LIGO and high energy cosmic neutrinos by IceCube, the era of multi-messenger astronomy is here and ePESSTO is well placed to play a major role.

The new instrument for the ESO NTT, which will replace SOFI and EFOSC2 is the Son of Xshooter (SOXS, PI Sergio Campana). This is due for final design review in 2018 and we envisage ePESSTO bridging the gap from now until SOXS is delivered to ESO in 2020.