A Systematic Search for Big Dippers in ASAS-SN

Dipper stars are extrinsically variable stars with deep dimming events due to extended, often dusty, structures produced by a wide range of mechanisms such as collisions, protoplanetary evolution or stellar winds. ASAS-SN has discovered 12 dipper-like objects as part of its normal operations. Here we systematically search the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:mo>∼</mml:mo> <mml:mn>5.1</mml:mn> </mml:mrow> </mml:math> million ASAS-SN targets with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:mn>13</mml:mn> <mml:mo>&lt;</mml:mo> <mml:mi>g</mml:mi> <mml:mo>&lt;</mml:mo> <mml:mn>14</mml:mn> </mml:mrow> </mml:math> ~mag for dippers with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:mi>Δ</mml:mi> <mml:mi>g</mml:mi> <mml:mo>≥</mml:mo> <mml:mn>0.3</mml:mn> </mml:mrow> </mml:math> ~mag to identify 4 new candidates. We also discover 15 long-period eclipsing binary candidates. We characterized the 19 new and 12 previously discovered objects using the ASAS-SN light curves and archival multi-wavelength data. We divide them into three categories: long-period eclipsing binaries with a single eclipse (13 total), long-period eclipsing binaries with multiple eclipses (7 total) and dipper stars with dust or disk occultations (11 total).