K2-140b-an eccentric 6.57 d transiting hot Jupiter in Virgo
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Authors: Giles, H. A. C.; Bayliss, D.; Espinoza, N.; Brahm, R.; Blanco-Cuaresma, S.; Shporer, A.; Armstrong, D.; Lovis, C.; Udry, S.; Bouchy, F.; Marmier, M.; Jordan, A.; Bento, J.; Cameron, A. Collier; Sefako, R.; Cochran, W. D.; Rojas, F.; Rabus, M.; Jenkins, S.; Jones, M.; Pantoja, B.; Soto, M.; Jensen-Clem, R.; Duev, D. A.; Salama, M.; Riddle, R.; Baranec, C.; Law, N. M.
Abstract
We present the discovery of K2-140b, a P = 6.57 d Jupiter-mass (M-P = 1.019 +/- 0.070 M-Jup) planet transiting a V = 12.5 (G5-spectral type) star in an eccentric orbit (e = 0.120(-0.046)(+0.056)) detected using a combination of K2 photometry and ground-based observations. With a radius of 1.095 +/- 0.018 R-Jup, the planet has a bulk density of 0.726 +/- 0.062 rho(Jup). The host star has a [Fe/H] of 0.12 +/- 0.045, and from the K2 light curve, we find a rotation period for the star of 16.3 +/- 0.1 d. This discovery is the 9th hot Jupiter from K2 and highlights K2's ability to detect transiting giant planets at periods slightly longer than traditional, ground- based surveys. This planet is slightly inflated, but much less than others with similar incident fluxes. These are of interest for investigating the inflation mechanism of hot Jupiters.
A possible giant planet orbiting the cataclysmic variable LX Ser
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN
Authors: Li, Kai; Hu, Shaoming; Zhou, Jilin; Wu, Donghong; Guo, Difu; Jiang, Yunguo; Gao, Dongyang; Chen, Xu; Wang, Xianyu
Abstract
LX Ser is a deeply eclipsing cataclysmic variable with an orbital period of 0.1584325 d. 62 new eclipse times were determined by our observations and the AAVSO International Data base. Combining all available eclipse times, we analyzed the O-C behavior of LX Ser. We found that the O-C diagram of LXSer shows a sinusoidal oscillation with a period of 22.8 yr and an amplitude of 0.00035 d. Two mechanisms (i.e., the Applegate mechanism and the light-travel time effect) are applied to explain the cyclic modulation. We found that it is difficult to apply the Applegate mechanism to explain the cyclic oscillation in the orbital period. Therefore, the cyclic period change is most likely to be caused by the light-travel time effect due to the presence of a third body. The mass of the tertiary component was determined to be M-3 similar to 7.5M(Jup). We supposed that the tertiary companion is plausibly a giant planet. The stability of the giant planet was checked, and we found that the multiple system is stable.
COA
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