A box-fitting algorithm in the search for periodic transits

By G. Kovacs, S. Zucker, T. Mazeh. 2002

893 citations recorded by the source corpus.

We study the statistical characteristics of a box-fitting algorithm to analyze stellar photometric time series in the search for periodic transits by extrasolar planets. The algorithm searches for signals characterized by a periodic alternation between two discrete levels, with much less time spent at the lower level. We present numerical as well as analytical results to predict the possible detection significance at various signal parameters. It is shown that the crucial parameter is the eective signal-to-noise ratio - the expected depth of the transit divided by the standard deviation of the measured photometric average within the transit. When this parameter exceeds the value of 6 we can expect a significant detection of the transit. We show that the box-fitting algorithm performs better than other methods available in the astronomical literature, especially for low signal-to-noise ratios.

Subfields: Astronomy and Astrophysics, Instrumentation, Statistical and Nonlinear Physics

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Citations in the corpus

A SYSTEMATIC SEARCH FOR TRANSITING PLANETS IN THE K2 DATA (2015, methodology): “It is worth noting that this model can be equivalently thought of as a (computationally expensive) generalization of the “Box Least Squares” (BLS; Kovács et al. 2002) method to a more sophisticated description of the noise and systematics.”
YSOVAR: THE FIRST SENSITIVE, WIDE-AREA, MID-INFRARED PHOTOMETRIC MONITORING OF THE ORION NEBULA CLUSTER (2011, methodology): “This – 8 – service uses the Lomb-Scargle (Scargle 1982), Box-fitting Least Squares (Kovács et al. 2002) and Plavchan (Plavchan et al. 2008b) algorithms for computing periodograms from time series data.”
THE XO PLANETARY SURVEY PROJECT: ASTROPHYSICAL FALSE POSITIVES (2010, methodology): “Each of these methods produced one set of input data for planetary transit search, for which we used the Box-fitting Least Squares algorithm (BLS; see Kovács et al. 2002), as modified by McCullough et al. (2005).”
WASP-47: A HOT JUPITER SYSTEM WITH TWO ADDITIONAL PLANETS DISCOVERED BY K2 (2015, positive): “A Box-Least-Squares (BLS; Kovács et al. 2002) periodogram search (as implemented in Muirhead et al. 2015) of the processed long cadence light curve identified the 4.16-day period hot Jupiter (WASP-47 b), a Neptune sized planet in a 9.03-day period (WASP-47 d), and a super-Earth in a 0.79-day…”
The effect of red noise on planetary transit detection (2006, result): “Our approach bears similarities with that of Jenkins et al. (2002), Kovács et al. (2002) and Sirko & Paczyński (2003), in accounting for the systematics in the noise by studying the properties of the photometric time-series over longer time-intervals.”
KEPLER-413B: A SLIGHTLY MISALIGNED, NEPTUNE-SIZE TRANSITING CIRCUMBINARY PLANET (2014, methodology): “To account for this, we developed an algorithm tailored for finding individual box-shaped features in a light curve (Kostov et al. 2013), based on the widely-used Box-fitting Least-Squares (BLS) method (Kovács et al. 2002).”
PLANETARY CANDIDATES FROM THE FIRST YEAR OF THE K2 MISSION (2015, methodology): “After flattening the light curve and performing outlier exclusion, we calculated a Box-Least-Squares (BLS) periodogram (Kovács et al. 2002), which is the heart of our transit search algorithm.”
WASP-19b: THE SHORTEST PERIOD TRANSITING EXOPLANET YET DISCOVERED (2010, methodology): “The resulting light curves were then run through our implementation of the box least squares algorithm (Kovács et al. 2002) designed to detect periodic transitshaped dips in brightness.”
TESS Eclipsing Binary Stars. I. Short-cadence Observations of 4584 Eclipsing Binaries in Sectors 1–26 (2021, methodology): “The final algorithm employed a traditional and well-tested approach to searching for transit-like signals: the box least squares (BLS) periodogram (Kovács et al. 2002).”
Identifying Exoplanets with Deep Learning: A Five-planet Resonant Chain around Kepler-80 and an Eighth Planet around Kepler-90 (2017, methodology): “In brief, our pipeline flattens the light curves by fitting a basis spline to the light curve with outlier rejection and uses a Box Least Squares (BLS, Kovács et al. 2002) periodogram search to detect transiting planets.”
HATSouth: A Global Network of Fully Automated Identical Wide-Field Telescopes (2012, methodology): “The selection routines are applied to the top five peaks in the BLS spectrum of a light curve.”
TRANSIT DETECTION IN THE MEarth SURVEY OF NEARBY M DWARFS: BRIDGING THE CLEAN-FIRST, SEARCH-LATER DIVIDE (2012, methodology): “In the context of other transit detection algorithms that pair BLS with a pre-search cleaning step, this Dinjected/σinjected has an important meaning.”