A New Analysis of the Exoplanet Hosting System Hd 6434

Abstract

The current goal of exoplanetary science is not only focused on detecting but characterizing planetary systems in hopes of understanding how they formed, evolved, and relate to the solar system. The Transit Ephemeris Refinement and Monitoring Survey (TERMS) combines both radial velocity (RV) and photometric data in order to achieve unprecedented ground-based precision in the fundamental properties of nearby, bright, exoplanet-hosting systems. Here we discuss HD 6434 and its planet, HD 6434b, which has a M p sin i = 0.44 M J mass and orbits every 22.0170 days with an eccentricity of 0.146. We have combined previously published RV data with new measurements to derive a predicted transit duration of ∼6 hr, or 0.25 days, and a transit probability of 4%. Additionally, we have photometrically observed the planetary system using both the 0.9 and 1.0 m telescopes at the Cerro Tololo Inter-American Observatory, covering 75.4% of the predicted transit window. We reduced the data using the automated TERMS Photometry Pipeline, developed to ensure consistent and accurate results. We determine a dispositive null result for the transit of HD 6434b, excluding the full transit to a depth of 0.9% and grazing transit due to impact parameter limitations to a depth of 1.6%.

Predicted Yield of Transits of Known Radial Velocity Exoplanets from the TESS Primary and Extended Missions

“…Efforts to detect or rule out transits of RV exoplanets include the Transit Ephemeris Refinement and Monitoring Survey (TERMS; Kane et al 2009), which has been refining transit ephemerides and conducting photometric transit searches for RV exoplanets for nearly a decade. TERMS, and other similar efforts, have thoroughly ruled out transits for the exoplanet hosts GJ 581 (e.g., López-Morales et al 2006;Dragomir et al 2012a), GJ 876 (e.g., Shankland et al 2006), HD 114762 (Kane et al 2011a), HD 63454 (Kane et al 2011b), HD 192263 (Dragomir et al 2012b, HD 38529 (b planet, Henry et al 2013), HD 130322 (b planet, Hinkel et al 2015a), 70 Vir (Kane et al 2015), HD 6434 (Hinkel et al 2015b), and HD 20782 (Kane et al 2016). Less confident null detections of transits have also been reported for HD 168443 b (Pilyavsky et al 2011), HD 37605 b (Wang et al 2012), HD 156846 b (Kane et al 2011c), and Proxima Cen b (e.g., Kipping et al 2017;Blank et al 2018).…”

Transits of Known Planets Orbiting a Naked-eye Star

“…Well-known examples of RV planets later found to transit include HD209458b (Charbonneau et al 2000;Henry et al 2000), HD189733b (Bouchy et al 2005), and HD80606b (Naef et al 2001;Fossey et al 2009;Garcia-Melendo & McCullough 2009;Laughlin et al 2009). Though the TERMS survey successfully discovered new planets (Wang et al 2012), destroyed old planets (Kane et al 2016b), characterized numerous host stars (e.g., Dragomir et al 2012;Hinkel et al 2015), and ruled out transits (e.g., Kane et al 2011aKane et al , 2011bPilyavsky et al 2011;Henry et al 2013), the primary science goal was largely impeded by ground-based observational window functions (von Braun et al 2009). However, the Transiting Exoplanet Survey Satellite (TESS) has observed most of the sky during the primary mission (Ricker et al 2015), including the known exoplanet hosts.…”