# Transits of Known Planets Orbiting a Naked-eye Star

Kane, Stephen R. and Yalcinkaya, Selcuk and Osborn, Hugh P. and Dalba, Paul A. and Nielsen, Louise D. and Vanderburg, Andrew and Mocnik, Teo and Hinkel, Natalie R. and Ostberg, Colby and Esmer, Ekrem Murat and Udry, Stephane and Fetherolf, Tara and Basturk, Ozgur and Ricker, George R. and Vanderspek, Roland and Latham, David W. and Seager, Sara and Winn, Joshua N. and Jenkins, Jon M. and Allart, Romain and Bailey, Jeremy and Bean, Jacob L. and Bouchy, Francois and Butler, R. Paul and Campante, Tiago L. and Carter, Brad D. and Daylan, Tansu and Deleuil, Magali and Diaz, Rodrigo F. and Dumusque, Xavier and Ehrenreich, David and Horner, Jonathan and Howard, Andrew W. and Isaacson, Howard and Jones, Hugh R. A. and Kristiansen, Martti H. and Lovis, Christophe and Marcy, Geoffrey W. and Marmier, Maxime and O'Toole, Simon J. and Pepe, Francesco and Ragozzine, Darin and Segransan, Damien and Tinney, C. G. and Turnbull, Margaret C. and Wittenmyer, Robert A. and Wright, Duncan J. and Wright, Jason T. (2020) Transits of Known Planets Orbiting a Naked-eye Star. The Astronomical Journal, 160 (3):129. pp. 1-10. ISSN 0004-6256

## Abstract

Some of the most scientifically valuable transiting planets are those that were already known from radial velocity (RV) surveys. This is primarily because their orbits are well characterized and they preferentially orbit bright stars that are the targets of RV surveys. The Transiting Exoplanet Survey Satellite (TESS) provides an opportunity to survey most of the known exoplanet systems in a systematic fashion to detect possible transits of their planets. HD 136352 (Nu<SUP>2</SUP> Lupi) is a naked-eye (V = 5.78) G-type main-sequence star that was discovered to host three planets with orbital periods of 11.6, 27.6, and 108.1 days via RV monitoring with the High Accuracy Radial velocity Planet Searcher (HARPS) spectrograph. We present the detection and characterization of transits for the two inner planets of the HD 136352 system, revealing radii of ${1.482}_{-0.056}^{+0.058}$ R<SUB>⊕</SUB> and ${2.608}_{-0.077}^{+0.078}$ R<SUB>⊕</SUB> for planets b and c, respectively. We combine new HARPS observations with RV data from the Keck/High Resolution Echelle Spectrometer and the Anglo-Australian Telescope, along with TESS photometry from Sector 12, to perform a complete analysis of the system parameters. The combined data analysis results in extracted bulk density values of ${\rho }_{b}={7.8}_{-1.1}^{+1.2}$ g cm<SUP>-3</SUP> and ${\rho }_{c}={3.50}_{-0.36}^{+0.41}$ g cm<SUP>-3</SUP> for planets b and c, respectively, thus placing them on either side of the radius valley. The combination of the multitransiting planet system, the bright host star, and the diversity of planetary interiors and atmospheres means this will likely become a cornerstone system for atmospheric and orbital characterization of small worlds.

Item Type: Article (Commonwealth Reporting Category C) Yes Live Archive Current - Institute for Advanced Engineering and Space Sciences - Centre for Astrophysics (1 Aug 2018 -) Current - Institute for Advanced Engineering and Space Sciences - Centre for Astrophysics (1 Aug 2018 -) 15 Oct 2020 01:34 21 Oct 2020 21:39 Exoplanets; Exoplanet atmospheres; Exoplanet structure; Transit; photometry; Radial velocity; 498; 487; 495; 1709; 1332; Astrophysics -; Earth and Planetary Astrophysics 02 Physical Sciences > 0201 Astronomical and Space Sciences > 020110 Stellar Astronomy and Planetary Systems E Expanding Knowledge > 97 Expanding Knowledge > 970102 Expanding Knowledge in the Physical Sciences https://doi.org/10.3847/1538-3881/aba835 http://eprints.usq.edu.au/id/eprint/39887