Can I read The Second Discovery from the COol Companions ON Ultrawide orbiTS (COCONUTS) Program: A Cold Wide-Orbit Exoplanet around a Young Field M Dwarf at 10.9 pc on EtoBox?

The Second Discovery from the COol Companions ON Ultrawide orbiTS (COCONUTS) Program: A Cold Wide-Orbit Exoplanet around a Young Field M Dwarf at 10.9 pc by Zhang, Zhoujian; Liu, Michael C.; Claytor, Zachary R.; Best, William M. J.; Dupuy, Trent J.; Siverd, Robert J. is a scholarly article available to read on EtoBox.

What is The Second Discovery from the COol Companions ON Ultrawide orbiTS (COCONUTS) Program: A Cold Wide-Orbit Exoplanet around a Young Field M Dwarf at 10.9 pc about?

We present the identification of the COCONUTS-2 system, composed of the M3 dwarf L 34-26 and the T9 dwarf WISEPA J075108.79$-$763449.6. Given their common proper motions and parallaxes, these two field objects constitute a physically bound pair with a projected separation of 594$"$ (6471 au). The primary star COCONUTS-2A has strong stellar activity (H$\alpha$, X-ray, and UV emission) and is rapidly rotating ($P_{\rm rot} = 2.83$ days), from which we estimate an age of 150-800 Myr. Comparing equatorial rotational velocity derived from the TESS light curve to spectroscopic $v\sin{i}$, we find COCONUTS-2A has a nearly edge-on inclination. The wide exoplanet COCONUTS-2b has an effective temperature of $T_{\rm eff}=434 \pm 9$ K, a surface gravity of $\log{g} = 4.11^{+0.11}_{-0.18}$ dex, and a mass of $M=6.3^{+1.5}_{-1.9}$ $M_{\rm Jup}$ based on hot-start evolutionary models, leading to a $0.016^{+0.004}_{-0.005}$ mass ratio for the COCONUTS-2 system. COCONUTS-2b is the second coldest (after WD 0806$-$661B) and the second widest (after TYC 9486-927-1 b) exoplanet imaged to date. Comparison of COCONUTS-2b's infrared photometry with ultracool model atmospheres suggests the presence of both

Author

Zhang, Zhoujian; Liu, Michael C.; Claytor, Zachary R.; Best, William M. J.; Dupuy, Trent J.; Siverd, Robert J.

Published

2021

Language

EN