• DOI:10.1051/0004-6361/201731855
• Corpus ID: 53400492

High-resolution Imaging of Transiting Extrasolar Planetary systems (HITEP). II. Lucky Imaging results from 2015 and 2016

@article{Evans2017HighresolutionIO,
  title={High-resolution Imaging of Transiting Extrasolar Planetary systems (HITEP). II. Lucky Imaging results from 2015 and 2016},
  author={D. F. Evans and John Southworth and Barry Smalley and U. G. J{\o}rgensen and Martin Dominik and Michael I. Andersen and Valerio Bozza and Daniel M. Bramich and Martin J. Burgdorf and Simona Ciceri and Giuseppe D’ago and R. Figuera Jaimes and S-H. Gu and Tobias C. Hinse and Th. Henning and M. Hundertmark and No{\'e} Kains and Eamonn Kerins and Heidi Korhonen and Rosita Kokotanekova and Michael Kuffmeier and Pen{\'e}lope Longa-Pe{\~n}a and Luigi Mancini and Jasmine MacKenzie and Andrius Popovas and Markus Rabus and Sohrab Rahvar and Sedighe Sajadian and Colin Snodgrass and Jesper F. Skottfelt and Jean Surdej and Ren{\'e} Tronsgaard and Eduardo Unda-Sanzana and Carolina von Essen and Yi‐Bo Wang and O. Wertz},
  journal={arXiv: Earth and Planetary Astrophysics},
  year={2017}
}

• D. Evans, J. Southworth, +33 authors O. Wertz
• Published 21 September 2017
• Physics, Geology
• arXiv: Earth and Planetary Astrophysics

The formation and dynamical history of hot Jupiters is currently debated, with wide stellar binaries having been suggested as a potential formation pathway. Additionally, contaminating light from both binary companions and unassociated stars can significantly bias the results of planet characterisation studies, but can be corrected for if the properties of the contaminating star are known. We search for binary companions to known transiting exoplanet host stars, in order to determine the multiplicity properties of hot Jupiter host stars. We also characterise unassociated stars along the line of sight, allowing photometric and spectroscopic observations of the planetary system to be corrected for contaminating light. We analyse lucky imaging observations of 97 Southern hemisphere exoplanet host stars, using the Two Colour Instrument on the Danish 1.54m telescope. For each detected companion star, we determine flux ratios relative to the planet host star in two passbands, and measure the relative position of the companion. The probability of each companion being physically associated was determined using our two-colour photometry. A catalogue of close companion stars is presented, including flux ratios, position measurements, and estimated companion star temperature. For companions that are potential binary companions, we review archival and catalogue data for further evidence. For WASP-77AB and WASP-85AB, we combine our data with historical measurements to determine the binary orbits, showing them to be moderately eccentric and inclined to the line of sight and planetary orbital axis. Combining our survey with the similar Friends of Hot Jupiters survey, we conclude that known hot Jupiter host stars show a deficit of high mass stellar companions compared to the field star population; however, this may be a result of the biases in detection and target selection by ground-based surveys.