Modeling Light Curves for Improved Classification

Many synoptic surveys are observing large parts of the sky multiple times. The resulting lightcurves provide a wonderful window to the dynamic nature of the universe. However, there are many significant challenges in analyzing these light curves. These include heterogeneity of the data, irregularly sampled data, missing data, censored data, known but variable measurement errors, and most importantly, the need to classify in astronomical objects in real time using these imperfect light curves. We describe a modeling-based approach using Gaussian process regression for generating critical measures representing features for the classification of such lightcurves. We demonstrate that our approach performs better by comparing it with past methods. Finally, we provide future directions for use in sky-surveys that are getting even bigger by the day.

[1]  Christina Gloeckner,et al.  Modern Applied Statistics With S , 2003 .

[2]  Ciro Donalek,et al.  Flashes in a star stream: Automated classification of astronomical transient events , 2012, 2012 IEEE 8th International Conference on E-Science.

[3]  Kirk D. Borne,et al.  Scientific Data Mining in Astronomy , 2009, Next Generation of Data Mining.

[4]  S. G. Djorgovski,et al.  Discovery, classification, and scientific exploration of transient events from the Catalina Real-time Transient Survey , 2011, 1111.0313.

[5]  A. J. Drake,et al.  FIRST RESULTS FROM THE CATALINA REAL-TIME TRANSIENT SURVEY , 2008, 0809.1394.

[6]  A. A. Mahabal,et al.  The Catalina Real-Time Transient Survey (CRTS) , 2011, 1102.5004.

[7]  Sergey E. Koposov,et al.  THE CATALINA SURVEYS PERIODIC VARIABLE STAR CATALOG , 2014, 1405.4290.

[8]  J. Richards,et al.  ON MACHINE-LEARNED CLASSIFICATION OF VARIABLE STARS WITH SPARSE AND NOISY TIME-SERIES DATA , 2011, 1101.1959.

[9]  R. Webbink,et al.  A Catalog and Atlas of Cataclysmic Variables: The Final Edition , 2005, astro-ph/0602278.

[10]  Kurt Hornik,et al.  kernlab - An S4 Package for Kernel Methods in R , 2004 .

[11]  Carl E. Rasmussen,et al.  Gaussian processes for machine learning , 2005, Adaptive computation and machine learning.

[12]  Adam A. Miller,et al.  ACTIVE LEARNING TO OVERCOME SAMPLE SELECTION BIAS: APPLICATION TO PHOTOMETRIC VARIABLE STAR CLASSIFICATION , 2011, 1106.2832.

[13]  Andy Liaw,et al.  Classification and Regression by randomForest , 2007 .

[14]  Pavlos Protopapas,et al.  Semi-parametric Robust Event Detection for Massive Time-Domain Databases , 2013, 1301.3027.

[15]  B. Silverman,et al.  Functional Data Analysis , 1997 .

[16]  Ciro Donalek,et al.  A novel variability-based method for quasar selection: evidence for a rest-frame ∼54 d characteristic time-scale , 2013, 1401.1785.

[17]  Stephen R. Kane,et al.  CHARACTERIZING THE VARIABILITY OF STARS WITH EARLY-RELEASE KEPLER DATA , 2010, 1009.1840.

[18]  S. G. Djorgovski,et al.  Feature selection strategies for classifying high dimensional astronomical data sets , 2013, 2013 IEEE International Conference on Big Data.