Modeling of a Spot on τ Boötis A - Possibly Induced by a Planet

• Autorzy: Dimitrov W. , Tokarek J. , Troianskyi V. , Godunova V. , Boneva D.

Identyfikatory

DOI

10.32023/0001-5237/75.1.3

• Języki publikacji: EN

Abstrakty

EN

Photometry of τ Boötis A acquired by MOST satellite shows variations, which could be explained by the presence of a spot on the host star surface, potentially induced by its planetary companion. We used the Wilson-Devinney method for modeling the light curve. The results from the literature describing the star-planet system were used. Although τ Boötis is a non-transiting system, the masses, radii, and orbital inclination are known. The dominating factor in the light curve is the stellar spot effect. The ellipsoidal variations and reflected light influence are not visible or very small. Modeling shows a strong correlation between co-latitude and spot size. There is a group of solutions that fits the data well. If we suppose that the spot is on the star's equator we could find an unambiguous solution. The spot is shifted due to the sub-planetary point in the rotation direction. The longitude of the circular spot center is 62.°75±0.03. The temperature contrast of the spot is very low, only a few degrees below ambient temperature. The spots cover a significant part of the stellar surface, its radius is 56°±4. We also presented a second solution, which better fits the data, for a much smaller spot at latitude ≈30° and radius of 9.°7±0.1. The influence of light reflected from the day side of the planet was also analyzed.

Słowa kluczowe

EN

stars: individual: τ Boötis A; planets and satellites: individual: τ Boötis Ab

• Wydawca: Copernicus Foundation for Polish Astronomy
• Czasopismo: Acta Astronomica
• Rocznik: 2025
• Tom: Vol. 75, No. 1
• Strony: 53--61
• Opis fizyczny: Bibliogr. 23 poz., rys., tab., wykr.

Twórcy

autor

Dimitrov W.

• Astronomical Observatory Institute, Faculty of Physics and Astronomy, Adam Mickiewicz University, ul. Słoneczna 36, 60-286 Poznań, Poland

autor

Tokarek J.

• Astronomical Observatory Institute, Faculty of Physics and Astronomy, Adam Mickiewicz University, ul. Słoneczna 36, 60-286 Poznań, Poland

autor

Troianskyi V.

• Astronomical Research Station of Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., 76018 Ivano-Frankivsk, Ukraine
• Department of Physics and Astronomy, Faculty of Physics and Technology, Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., 76025 Ivano-Frankivsk, Ukraine
• Astronomical Observatory of Odesa I. I. Mechnikov National University, 1v Marazliyivska str., 65014 Odesa, Ukraine

autor

Godunova V.

• ICAMER Observatory of NASU, 27 Acad. Zabolotnoho str., Kyiv, 03143, Ukraine

autor

Boneva D.

• Space Research and Technology Institute, Bulgarian Academy of Sciences, Acad. Georgi Bonchev Str., Bl. 1, 1113 Sofia, Bulgaria

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