Exploring the variable sky with linear. III. classification of periodic light curves
We describe the construction of a highly reliable sample of ~7000 optically faint periodic variable stars with light curves obtained by the asteroid survey LINEAR across 10,000 deg[superscript 2] of the northern sky. The majority of these variables have not been cataloged yet. The sample flux limit...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | en_US |
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IOP Publishing
2015
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| Online Access: | http://hdl.handle.net/1721.1/92739 |
| _version_ | 1811093490883362816 |
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| author | Palaversa, Lovro Ivezic, Zeljko Eyer, Laurent Ruzdjak, Domagoj Sudar, Davor Galin, Mario Kroflin, Andrea Mesaric, Martina Munk, Petra Vrbanec, Dijana Bozic, Hrvoje Loebman, Sarah Sesar, Branimir Rimoldini, Lorenzo Hunt-Walker, Nicholas VanderPlas, Jacob Westman, David Stuart, J. Scott Becker, Andrew C. Srdoc, Gregor Wozniak, Przemyslaw Oluseyi, Hakeem |
| author2 | Lincoln Laboratory |
| author_facet | Lincoln Laboratory Palaversa, Lovro Ivezic, Zeljko Eyer, Laurent Ruzdjak, Domagoj Sudar, Davor Galin, Mario Kroflin, Andrea Mesaric, Martina Munk, Petra Vrbanec, Dijana Bozic, Hrvoje Loebman, Sarah Sesar, Branimir Rimoldini, Lorenzo Hunt-Walker, Nicholas VanderPlas, Jacob Westman, David Stuart, J. Scott Becker, Andrew C. Srdoc, Gregor Wozniak, Przemyslaw Oluseyi, Hakeem |
| author_sort | Palaversa, Lovro |
| collection | MIT |
| description | We describe the construction of a highly reliable sample of ~7000 optically faint periodic variable stars with light curves obtained by the asteroid survey LINEAR across 10,000 deg[superscript 2] of the northern sky. The majority of these variables have not been cataloged yet. The sample flux limit is several magnitudes fainter than most other wide-angle surveys; the photometric errors range from ~0.03 mag at r = 15 to ~0.20 mag at r = 18. Light curves include on average 250 data points, collected over about a decade. Using Sloan Digital Sky Survey (SDSS) based photometric recalibration of the LINEAR data for about 25 million objects, we selected ~200,000 most probable candidate variables with r < 17 and visually confirmed and classified ~7000 periodic variables using phased light curves. The reliability and uniformity of visual classification across eight human classifiers was calibrated and tested using a catalog of variable stars from the SDSS Stripe 82 region and verified using an unsupervised machine learning approach. The resulting sample of periodic LINEAR variables is dominated by 3900 RR Lyrae stars and 2700 eclipsing binary stars of all subtypes and includes small fractions of relatively rare populations such as asymptotic giant branch stars and SX Phoenicis stars. We discuss the distribution of these mostly uncataloged variables in various diagrams constructed with optical-to-infrared SDSS, Two Micron All Sky Survey, and Wide-field Infrared Survey Explorer photometry, and with LINEAR light-curve features. We find that the combination of light-curve features and colors enables classification schemes much more powerful than when colors or light curves are each used separately. An interesting side result is a robust and precise quantitative description of a strong correlation between the light-curve period and color/spectral type for close and contact eclipsing binary stars (β Lyrae and W UMa): as the color-based spectral type varies from K4 to F5, the median period increases from 5.9 hr to 8.8 hr. These large samples of robustly classified variable stars will enable detailed statistical studies of the Galactic structure and physics of binary and other stars and we make these samples publicly available. |
| first_indexed | 2024-09-23T15:45:41Z |
| format | Article |
| id | mit-1721.1/92739 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:45:41Z |
| publishDate | 2015 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/927392022-09-29T15:58:28Z Exploring the variable sky with linear. III. classification of periodic light curves Palaversa, Lovro Ivezic, Zeljko Eyer, Laurent Ruzdjak, Domagoj Sudar, Davor Galin, Mario Kroflin, Andrea Mesaric, Martina Munk, Petra Vrbanec, Dijana Bozic, Hrvoje Loebman, Sarah Sesar, Branimir Rimoldini, Lorenzo Hunt-Walker, Nicholas VanderPlas, Jacob Westman, David Stuart, J. Scott Becker, Andrew C. Srdoc, Gregor Wozniak, Przemyslaw Oluseyi, Hakeem Lincoln Laboratory Stuart, J. Scott We describe the construction of a highly reliable sample of ~7000 optically faint periodic variable stars with light curves obtained by the asteroid survey LINEAR across 10,000 deg[superscript 2] of the northern sky. The majority of these variables have not been cataloged yet. The sample flux limit is several magnitudes fainter than most other wide-angle surveys; the photometric errors range from ~0.03 mag at r = 15 to ~0.20 mag at r = 18. Light curves include on average 250 data points, collected over about a decade. Using Sloan Digital Sky Survey (SDSS) based photometric recalibration of the LINEAR data for about 25 million objects, we selected ~200,000 most probable candidate variables with r < 17 and visually confirmed and classified ~7000 periodic variables using phased light curves. The reliability and uniformity of visual classification across eight human classifiers was calibrated and tested using a catalog of variable stars from the SDSS Stripe 82 region and verified using an unsupervised machine learning approach. The resulting sample of periodic LINEAR variables is dominated by 3900 RR Lyrae stars and 2700 eclipsing binary stars of all subtypes and includes small fractions of relatively rare populations such as asymptotic giant branch stars and SX Phoenicis stars. We discuss the distribution of these mostly uncataloged variables in various diagrams constructed with optical-to-infrared SDSS, Two Micron All Sky Survey, and Wide-field Infrared Survey Explorer photometry, and with LINEAR light-curve features. We find that the combination of light-curve features and colors enables classification schemes much more powerful than when colors or light curves are each used separately. An interesting side result is a robust and precise quantitative description of a strong correlation between the light-curve period and color/spectral type for close and contact eclipsing binary stars (β Lyrae and W UMa): as the color-based spectral type varies from K4 to F5, the median period increases from 5.9 hr to 8.8 hr. These large samples of robustly classified variable stars will enable detailed statistical studies of the Galactic structure and physics of binary and other stars and we make these samples publicly available. United States. Air Force (Contract FA8721-05-C-0002) 2015-01-07T19:51:50Z 2015-01-07T19:51:50Z 2013-09 2013-06 Article http://purl.org/eprint/type/JournalArticle 0004-6256 1538-3881 http://hdl.handle.net/1721.1/92739 Palaversa, Lovro, Zeljko Ivezic, Laurent Eyer, Domagoj Ruzdjak, Davor Sudar, Mario Galin, Andrea Kroflin, et al. “Exploring the Variable Sky with Linear. III. Classification of Periodic Light Curves.” The Astronomical Journal 146, no. 4 (September 16, 2013): 101. © 2013 The American Astronomical Society en_US http://dx.doi.org/10.1088/0004-6256/146/4/101 Astronomical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf IOP Publishing American Astronomical Society |
| spellingShingle | Palaversa, Lovro Ivezic, Zeljko Eyer, Laurent Ruzdjak, Domagoj Sudar, Davor Galin, Mario Kroflin, Andrea Mesaric, Martina Munk, Petra Vrbanec, Dijana Bozic, Hrvoje Loebman, Sarah Sesar, Branimir Rimoldini, Lorenzo Hunt-Walker, Nicholas VanderPlas, Jacob Westman, David Stuart, J. Scott Becker, Andrew C. Srdoc, Gregor Wozniak, Przemyslaw Oluseyi, Hakeem Exploring the variable sky with linear. III. classification of periodic light curves |
| title | Exploring the variable sky with linear. III. classification of periodic light curves |
| title_full | Exploring the variable sky with linear. III. classification of periodic light curves |
| title_fullStr | Exploring the variable sky with linear. III. classification of periodic light curves |
| title_full_unstemmed | Exploring the variable sky with linear. III. classification of periodic light curves |
| title_short | Exploring the variable sky with linear. III. classification of periodic light curves |
| title_sort | exploring the variable sky with linear iii classification of periodic light curves |
| url | http://hdl.handle.net/1721.1/92739 |
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