RESULTS

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ASAS-SN has discovered:

• ~220,000 variable stars
• ~1,100 supernovae
• ~1,500 cataclysmic variable star
• ~100 large amplitude M/L-dwarf flares
• ~50 AGN/blazar outbursts
• 8 tidal disruption events (TDEs)
• 3 changing-look AGN
• 2 comets
• 1 “killer asteroid”

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Citizen ASAS-SN Data Release I

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Citizen ASAS-SN Data Release I: Variable Star Classification Using Citizen Science
Christy, C. T.; Jayasinghe, T.; Stanek, K. Z.; Kochanek, C. S.; Way, Z.; Prieto, J. L.; Shappee, B. J.; Holoien, T. W. -S.; Thompson, T. A.; Schneider, A.

Here, we present the first results from Citizen ASAS-SN and the associated DR1 catalog of g-band variable stars.

Citizen ASAS-SN utilizes the newer, deeper, higher cadence ASAS-SN g-band data and tasks volunteers to classify periodic variable star candidates based on their phased light curves. We started our project with 40,640 new variable candidates from an input list of ∼7.4 million stars with δ < −60∘. In addition to recovering ~18,000 known variables, our volunteers were able to make 10,420 new variable star discoveries, consisting of 4,234 pulsating variables, 3,132 rotational variables, 2,923 eclipsing binaries, and 131 variables flagged as Unknown. Our citizen scientists classified known variable stars with an accuracy of 89% for pulsating variables, 81% for eclipsing binaries, and 49% for rotational variables. We examine our volunteers' performance, agreement between volunteers, and compare the citizen science classifications with our machine learning classifier updated for the g-band light curves. In general, user activity correlates with higher classification accuracy. We used the Citizen ASAS-SN DR1 "Junk" classifications to develop an effective machine learning classifier to separate real from false variables, and there is a clear path for using this "Junk" training set to significantly improve our primary machine learning classifier and our variable star candidate selection process. We also illustrate the value of Citizen ASAS-SN for identifying unusual variables with several examples.

Download catalog and light curves
Usernames of volunteers who contributed to DR1

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Citizen ASAS-SN Research Note

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Citizen ASAS-SN: Citizen Science with The All-Sky Automated Survey for SuperNovae (ASAS-SN)
Christy, C. T.; Jayasinghe, T.; Stanek, K. Z.; Kochanek, C. S.; Way, Z.; Prieto, J. L.; Shappee, B. J.; Holoien, T. W. -S.; Thompson, T. A.

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The ASAS-SN Catalog of Variable Stars

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The ASAS-SN Catalog of Variable Stars I: The Serendipitous Survey
Jayasinghe, T.; Kochanek, C. S.; Stanek, K. Z.; Shappee, B. J.; Holoien, T. W. -S.; Thompson, Todd A.; Prieto, J. L.; Dong, Subo; Pawlak, M.; Pejcha, O.; Pojmanski, G.; Otero, S.; Hurst, N.; Will, D., 2018, MNRAS, 477, 3145

The ASAS-SN Catalog of Variable Stars II: Uniform Classification of 412,000 Known Variables
Jayasinghe, T.; Stanek, K. Z.; Kochanek, C. S.; Shappee, B. J.; Holoien, T. W. -S.; Thompson, Todd A.; Prieto, J. L.; Dong, Subo; Pawlak, M.; Pejcha, O.; Shields, J. V.; Pojmanski, G.; Otero, S.; Britt, C. A.; Will, D., 2019, MNRAS, 486, 1907

The ASAS-SN Catalog of Variable Stars III: Variables in the Southern TESS Continuous Viewing Zone
Jayasinghe, T.; Stanek, K. Z.; Kochanek, C. S.; Shappee, B. J.; Holoien, T. W. -S.; Thompson, Todd A.; Prieto, J. L.; Dong, Subo; Pawlak, M.; Pejcha, O.; Shields, J. V.; Pojmanski, G.; Otero, S.; Hurst, N.; Britt, C. A.; Will, D., 2019, MNRAS, 485, 961

The ASAS-SN Catalog of Variable Stars IV. Periodic variables in the APOGEE survey
Pawlak, Michał; Pejcha, O.; Jakubčík, P.; Jayasinghe, T.; Kochanek, C. S.; Stanek, K. Z.; Shappee, B. J.; Holoien, T. W. -S.; Thompson, Todd A.; Prieto, J. L.; Dong, S.; Shields, J. V.; Pojmanski, G.; Britt, C. A.; Will, D., 2019, MNRAS, 487, 5932

The ASAS-SN Catalog of Variable Stars V: Variables in the Southern Hemisphere
Jayasinghe, T.; Stanek, K. Z.; Kochanek, C. S.; Shappee, B. J.; Holoien, T. W. -S.; Thompson, T. A.; Prieto, J. L.; Dong, S.; Pawlak, M.; Pejcha, O.; Shields, J. V.; Pojmanski, G.; Otero, S.; Hurst, N.; Britt, C. A.; Will, D., 2020, MNRAS, 491, 13

The ASAS-SN Catalog of Variable Stars VI: An All-Sky Catalog of δ Scuti stars
Jayasinghe, T.; Stanek, K. Z.; Kochanek, C. S.; Vallely, P. J.; Shappee, B. J.; Holoien, T. W. -S.; Thompson, Todd A.; Prieto, J. L.; Pejcha, O.; Fausnaugh, M.; Otero, S.; Hurst, N.; Will, D., 2020, MNRAS, 493, 4186

The ASAS-SN Catalog of Variable Stars VII: Contact Binaries are Different Above and Below the Kraft Break
Jayasinghe, T.; Stanek, K. Z.; Kochanek, C. S.; Shappee, B. J.; Pinsonneault, M. H.; Holoien, T. W. -S.; Thompson, Todd A.; Prieto, J. L.; Pawlak, M.; Pejcha, O.; Pojmanski, G.; Otero, S.; Hurst, N.; Will, D., 2020, MNRAS, 493, 4045

The ASAS-SN Catalog of Variable Stars VIII: 'Dipper' stars in the Lupus star-forming region
Bredall, J. W.; Shappee, B. J.; Gaidos, E.; Jayasinghe, T.; Vallely, P.; Stanek, K. Z.; Kochanek, C. S.; Gagné, J.; Hart, K.; Holoien, T. W. -S.; Prieto, J. L.; Van Saders, J., 2020, MNRAS, 496, 3257

The ASAS-SN Catalog of Variable Stars IX: The Spectroscopic Properties of Galactic Variable Stars
Jayasinghe, T.; Kochanek, C. S.; Stanek, K. Z.; Shappee, B. J.; Holoien, T. W. -S.; Thompson, Todd A.; Prieto, J. L.; Dong, Subo; Pawlak, M.; Pejcha, O.; Pojmanski, G.; Otero, S.; Hurst, N.; Will, D., 2020, MNRAS, in review

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Selected work on unusual variable stars

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An Extreme Amplitude, Massive Heartbeat System in the LMC Characterized Using ASAS-SN and TESS
Jayasinghe, T.; Stanek, K. Z.; Kochanek, C. S.; Thompson, Todd A.; Shappee, B. J.; Fausnaugh, M., 2019, MNRAS, 489, 4705

A noninteracting low-mass black hole─giant star binary system
Thompson, Todd A.; Kochanek, Christopher S.; Stanek, Krzysztof Z.; Badenes, Carles; Post, Richard S.; Jayasinghe, Tharindu; Latham, David W.; Bieryla, Allyson; Esquerdo, Gilbert A.; Berlind, Perry; Calkins, Michael L.; Tayar, Jamie; Lindegren, Lennart; Johnson, Jennifer A.; Holoien, Thomas W. -S.; Auchettl, Katie; Covey, Kevin, 2019, Sci, 366, 637

An all-sky search for R Coronae Borealis stars in ASAS-SN
Shields, J. V.; Jayasinghe, T.; Stanek, K. Z.; Kochanek, C. S.; Shappee, B. J.; Holoien, T. W. -S.; Thompson, Todd A.; Prieto, J. L.; Dong, Subo, 2019, MNRAS, 483, 4470

ASAS-SN Identification of a Detached Eclipsing Binary System with a ~7.3 Year Period
Jayasinghe, T.; Stanek, K. Z.; Kochanek, C. S.; Shappee, B. J.; Holoien, T. W. -S.; Thompson, T. A.; Prieto, J. L.; Dong, Subo; Stevens, D. J., RNAAS, 2, 125

ASAS-SN Discovery of an Unusual, Deep Dimming Episode of a Previously Non-Variable Star
Jayasinghe, T.; Stanek, K. Z.; Kochanek, C. S.; Vallely, P.; Shields, J. V.; Thompson, T. A.; Shappee, B. J.; Holoien, T. W. -S.; Prieto, J. L.; Dong, Subo; Stritzinger, M., 2019, ATel, 12836

ASAS-SN Discovery of an Unusual Stellar System with Deep Dimming Episodes
Way, Z.; Jayasinghe, T.; Stanek, K. Z.; Kochanek, C. S.; Vallely, P.; Basinger, C.; Thompson, T. A.; Shappee, B. J.; Holoien, T. W. -S.; Prieto, J. L.; Dong, Subo; Stritzinger, M., 2019, ATel, 13106

ASAS-SN Discovery of an Unusual, Rapidly Fading Star
Way, Z.; Stanek, K. Z.; Kochanek, C. S.; Jayasinghe, T.; Vallely, P.; Basinger, C.; Thompson, T. A.; Shappee, B. J.; Holoien, T. W. -S.; Prieto, J. L.; Dong, Subo; Stritzinger, M., 2019, ATel, 13346

ASAS-SN Discovery of a Heavily Reddened Eclipsed Giant Star in a 750 day Orbit
Jayasinghe, T.; Stanek, K. Z.; Kochanek, C. S.; Way, Z.; Vallely, P.; Basinger, C.; Thompson, T. A.; Shappee, B. J.; Holoien, T. W. -S.; Prieto, J. L.; Dong, Subo, 2020, ATel, 13745

ASAS-SN Discovery of an Unusually Luminous Cataclysmic Variable Candidate Undergoing a Dimming Episode
Jayasinghe, T.; Stanek, K. Z.; Kochanek, C. S.; Way, Z.; Vallely, P.; Basinger, C.; Thompson, T. A.; Shappee, B. J.; Holoien, T. W. -S.; Prieto, J. L.; Dong, Subo, 2020, ATel, 13824