META-CLASSIFICATION FOR VARIABLE STARS

• Published in: The Astrophysical journal 2016-03, Vol.819 (1), p.18
• Main Authors: Pichara, Karim, Protopapas, Pavlos, León, Daniel
• Format: Article
• Language: English
• Subjects: Algorithms; Astronomical bodies; Automation; Classification; Computer simulation; Mathematical models; methods: data analysis; Rebuilding; stars: statistics; stars: variables: general; surveys; Variable stars
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/0004-637X/819/1/18

ABSTRACT The need for the development of automatic tools to explore astronomical databases has been recognized since the inception of CCDs and modern computers. Astronomers already have developed solutions to tackle several science problems, such as automatic classification of stellar objects, outlier detection, and globular clusters identification, among others. New scientific problems emerge, and it is critical to be able to reuse the models learned before, without rebuilding everything from the beginning when the sciencientific problem changes. In this paper, we propose a new meta-model that automatically integrates existing classification models of variable stars. The proposed meta-model incorporates existing models that are trained in a different context, answering different questions and using different representations of data. A conventional mixture of expert algorithms in machine learning literature cannot be used since each expert (model) uses different inputs. We also consider the computational complexity of the model by using the most expensive models only when it is necessary. We test our model with EROS-2 and MACHO data sets, and we show that we solve most of the classification challenges only by training a meta-model to learn how to integrate the previous experts.