Otto Trust
(Department of Physics, Mbarara University of Science and Technology, P.O. Box 1410, Mbarara, Uganda / Department of Physics, Kyambogo University, P.O. Box 1, Kyambogo, Uganda / Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany)
We present the first homogeneous photometric and spectroscopic study of four bright field stars (HD 73135, BD+190 2045, BD+190 2046, and TYC 1395-855-1) that lie in the immediate vicinity of the variable HD 73045. These were monitored, but never fully analysed, by the long-running Nainital-Cape Survey. Johnson-BV CCD time-series from four 0.4-1.3 m telescopes show all these stars to be constant at ≤0.12 mag level, yet space-based K2 Campaigns 5 and 18 reveal low-amplitude variability only in HD 73135 and BD+190 2045. A 1.48 d doublet in HD 73135 is consistent with rotational modulation, possibly, by abundance spots. BD+190 2045 exhibits a rich 0.08-0.40 d-1 forest of γ-Doradus g-modes. BD+190 2046 and TYC 1395-855-1 display only marginal 10-20 ppm signals compatible with red-giant granulation. In addition, high-resolution HERMES spectra confirm HD 73135's Am nature (kA7hF1mF2) and show Sr-Ba overabundances of ~+1 dex. BD+190 2045 is a chemically normal F8V star, while BD+190 2046 and TYC1395-855-1 are K1-K2 sub-giants. Using spectroscopic constraints, we performed the first-step towards precise characterisation of these stars, yielding the masses, radii, and ages. These stars are located just 60 from the planned PLATO North-Ecliptic Ridge field, hence furnish benchmark targets for forthcoming asteroseismic and exoplanet surveys.
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Otto Trust
(Department of Physics, Mbarara University of Science and Technology, P.O. Box 1410, Mbarara, Uganda / Department of Physics, Kyambogo University, P.O. Box 1, Kyambogo, Uganda / Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany)
Dr
Santosh Joshi
(Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital- 263002, India)
Dr
Benard Nsamba
(DepartmDepartment of Physics, Kyambogo University, P.O. Box 1, Kyambogo, Uganda / Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany / Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching, Germany)
Dr
Sharon Aol
(Department of Physics, Mbarara University of Science and Technology, P.O. Box 1410, Mbarara, Uganda)
Mr
Owen Vermeulen
(Institute of Astronomy, KU Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium)
Mr
Ronald Ssembatya
(Department of Physics, Faculty of Science, Kyambogo University, P.O. Box 1, Kyambogo, Uganda)
Dr
Peter De Cat
(Royal Observatory of Belgium, Ringlaan 3, B-1180 Brussel, Belgium)
Dr
Patricia Lampens
(Royal Observatory of Belgium, Ringlaan 3, B-1180 Brussel, Belgium)
Dr
Sydney Barnes
(Leibniz-Institutfür Astrophysik Potsdam (AIP) An der Sternwarte 16 14482 Potsdam)
Dr
Partha Goswami
(Dakshin Kamrup College, Gauhati University, Assam-781125-India)
Mr
Athul Dileep
(Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital- 263002, India)
Mr
Surath Ghosh
(Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital- 263002, India)
Dr
Pramod Kumar
(Indian Institute of Astrophysics, Koramangala, Bangalore-560034, India)
Prof.
Edward Jurua
(Department of Physics, Mbarara University of Science and Technology, P.O. Box 1410, Mbarara, Uganda)
Mr
Mrinmoy Sakar
(Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital- 263002, India)
Dr
Sarabjeet Bedi
(Department of CSIT, M. J. P. Rohilkhand University, Bareilly, Uttar Pradesh-243006, India)
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