TY - JOUR
T1 - High-resolution imaging of transiting extrasolar planetary systems (HITEP) II. Lucky imaging results from 2015 and 2016
AU - Evans, D. F.
AU - Southworth, J.
AU - Smalley, B.
AU - Jørgensen, U. G.
AU - Dominik, M.
AU - Andersen, M. I.
AU - Bozza, V.
AU - Bramich, D. M.
AU - Burgdorf, M. J.
AU - Ciceri, S.
AU - D'Ago, G.
AU - Jaimes, R. Figuera
AU - Gu, S. H.
AU - Hinse, T. C.
AU - Henning, Th
AU - Hundertmark, M.
AU - Kains, N.
AU - Kerins, E.
AU - Korhonen, H.
AU - Kokotanekova, R.
AU - Kuffmeier, M.
AU - Longa-Peña, P.
AU - Mancini, L.
AU - MacKenzie, J.
AU - Popovas, A.
AU - Rabus, M.
AU - Rahvar, S.
AU - Sajadian, S.
AU - Snodgrass, C.
AU - Skottfelt, J.
AU - Surdej, J.
AU - Tronsgaard, R.
AU - Unda-Sanzana, E.
AU - Von Essen, C.
AU - Wang, Yi Bo
AU - Wertz, O.
PY - 2018/2
Y1 - 2018/2
N2 - Context. 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. Aims. 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 search for and characterise unassociated stars along the line of sight, allowing photometric and spectroscopic observations of the planetary system to be corrected for contaminating light. Methods. We analyse lucky imaging observations of 97 Southern hemisphere exoplanet host stars, using the Two Colour Instrument on the Danish 1.54 m 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. Results. 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 hence 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.
AB - Context. 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. Aims. 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 search for and characterise unassociated stars along the line of sight, allowing photometric and spectroscopic observations of the planetary system to be corrected for contaminating light. Methods. We analyse lucky imaging observations of 97 Southern hemisphere exoplanet host stars, using the Two Colour Instrument on the Danish 1.54 m 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. Results. 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 hence 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.
KW - Dynamical evolution and stability - planets and satellites
KW - Formation -Techniques
KW - High angular resolution - binaries
KW - Planets and satellites
KW - Visual
UR - http://www.scopus.com/inward/record.url?scp=85042594707&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/201731855
DO - 10.1051/0004-6361/201731855
M3 - Article
AN - SCOPUS:85042594707
SN - 0004-6361
VL - 610
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A20
ER -