Imperial College London


Faculty of Natural SciencesDepartment of Physics

Professor of Astrostatistics; CLCC Director



+44 (0)20 7594 7793r.trotta Website CV




Mrs Sheila Ekudo +44 (0)20 7594 2086




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BibTex format

author = {Revsbech, EA and Trotta, R and van, Dyk DA},
doi = {mnras/stx2570},
journal = {Monthly Notices of the Royal Astronomical Society},
title = {STACCATO: a novel solution to supernova photometric classification with biased training sets},
url = {},
volume = {473},
year = {2017}

RIS format (EndNote, RefMan)

AB - We present a new solution to the problem of classifying Type Ia supernovae from their light curves alone given a spectroscopically confirmed but biased training set, circumventing the need to obtain an observationally expensive unbiased training set. We use Gaussian processes (GPs) to model the supernovae's (SN's) light curves, and demonstrate that the choice of covariance function has only a small influence on the GPs ability to accurately classify SNe. We extend and improve the approach of Richards et al. – a diffusion map combined with a random forest classifier – to deal specifically with the case of biased training sets. We propose a novel method called Synthetically Augmented Light Curve Classification (STACCATO) that synthetically augments a biased training set by generating additional training data from the fitted GPs. Key to the success of the method is the partitioning of the observations into subgroups based on their propensity score of being included in the training set. Using simulated light curve data, we show that STACCATO increases performance, as measured by the area under the Receiver Operating Characteristic curve (AUC), from 0.93 to 0.96, close to the AUC of 0.977 obtained using the ‘gold standard’ of an unbiased training set and significantly improving on the previous best result of 0.88. STACCATO also increases the true positive rate for SNIa classification by up to a factor of 50 for high-redshift/low-brightness SNe.
AU - Revsbech,EA
AU - Trotta,R
AU - van,Dyk DA
DO - mnras/stx2570
PY - 2017///
SN - 0035-8711
TI - STACCATO: a novel solution to supernova photometric classification with biased training sets
T2 - Monthly Notices of the Royal Astronomical Society
UR -
UR -
VL - 473
ER -