CzeV1731: The unique doubly eclipsing quadruple system^⋆

¹ Astronomical Institute, Charles University, Faculty of Mathematics and Physics, V Holešovičkách 2, 180 00 Praha 8, Czech Republic
e-mail: zasche@sirrah.troja.mff.cuni.cz
² Variable Star and Exoplanet Section of the Czech Astronomical Society, Vsetínská 941/78, 757 01 Valašské, Meziříčí, Czech Republic
³ Thüringer Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany
⁴ Department of Physics, Lehigh University, 16 Memorial Drive East, Bethlehem, PA 18015, USA
⁵ NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
⁶ SETI Institute, 189 Bernardo Ave, Suite 200, Mountain View, CA 94043, USA
⁷ Astronomical Institute, Academy of Sciences, Fričova 298, 251 65 Ondřejov, Czech Republic
⁸ Research Centre for Theoretical Physics and Astrophysics, Institute of Physics, Silesian University in Opava, Bezručovo nám. 13, 746 01 Opava, Czech Republic
⁹ Private Observatory, Pohoří 71, 254 01 Jílové u Prahy, Czech Republic
¹⁰ FZU – Institute of Physics of the Czech Academy of Sciences, Na Slovance 1999/2, 182 21 Praha, Czech Republic
¹¹ National and Kapodistrian University of Athens, Department of Physics, Section of Astrophysics, Astronomy and Mechanics, 15784 Zografos, Athens, Greece
¹² Vanderbilt University, Department of Physics & Astronomy, 6301 Stevenson Center Ln., Nashville, TN 37235, USA
¹³ Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210, USA
¹⁴ Center for Astrophysics Harvard and Smithsonian, 60 Garden St, Cambridge, MA 02138, USA
¹⁵ Department of Astronomy & Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802, USA
¹⁶ Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802, USA

Received: 15 June 2020
Accepted: 21 July 2020

Abstract

We report the discovery of the relatively bright (V = 10.5 mag), doubly eclipsing 2+2 quadruple system CzeV1731. This is the third known system of its kind, in which the masses are determined for all four stars and both the inner and outer orbits are characterized. The inner eclipsing binaries are well-detached systems moving on circular orbits: pair A with period P_A = 4.10843 d and pair B with P_B = 4.67552 d. The inner binaries contain very similar components (q  ≈  1.0), making the whole system a so-called double twin. The stars in pair B have slightly larger luminosities and masses and pair A shows deeper eclipses. All four components are main-sequence stars of F/G spectral type. The mutual orbit of the two pairs around the system barycenter has a period of about 34 yr and an eccentricity of about 0.38. However, further observations are needed to reveal the overall architecture of the whole system, including the mutual inclinations of all orbits. This is a promising target for interferometry to detect the double at about 59 mas and ΔM_bol <  1 mag.