1161 transients classified by PESSTO so far
277 transients are being followed by PESSTO

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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.


PESSTO SSDR3 Data Release has been published and is now available for download from the ESO Data Archive. The spectra can be accessed from here and the SOFI imaging data from here.

In four years of operations, PESSTO has taken spectra of 1168 distinct objects. From this list, 161 supernovae (10 of which are super-luminous supernovae), 2 supernova imposters, 3 Tidal Disruption Events, 1 unclassified objects and 1 AGN were picked as interesting science targets and these were scheduled for follow-up time series EFOSC2 optical spectroscopy, with the brightest also having SOFI spectra taken.

In total SSDR3 contains 21.29GB of data. In total there are 2851 EFOSC2 spectra released. These include 1753 EFOSC spectra of the 168 PESSTO Key Science targets which are chosen for detailed follow-up. The remaining 1098 EFOSC spectra relate to 1000 objects for which we took classification spectra but did not pursue a detailed follow-up campaign. 224 SOFI spectra where also taken of the Key Science targets.

Total number of science files released in the various formats is described in the table below.

The release descriptions for the data products can be found here and further information can be found in the ESO news archive.

From detailed download instructions please read our wiki article.

If you use these data in a publication, please add the following acknowledgement AND a citation to our PESSTO Survey paper, Smartt et al. 2015 A&A, 579, 40:

“This work is based (in part) on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile as part of PESSTO, (the Public ESO Spectroscopic Survey for Transient Objects Survey) ESO program 188.D-3003, 191.D-0935, 197.D-1075.”

a few of the most recent PESSTO papers ...

LSQ14efd: observations of the cooling of a shock break-out event in a type Ic Supernova  Barbarino, C.; Botticella, M. T.; Dall'Ora, M. et al.
OGLE-2014-SN-131: A long-rising Type Ibn supernova from a massive progenitor  Karamehmetoglu, E.; Taddia, F.; Sollerman, J. et al.