TY - JOUR
T1 - A Search for Exoplanets around Northern Circumpolar Stars. VIII. Filtering Out a Planet Cycle from the Multi-Period Radial Velocity Variations in M Giant HD 36384
AU - Lee, Byeong Cheol
AU - Jeong, Gwanghui
AU - Koo, Jae Rim
AU - Lim, Beomdu
AU - Park, Myeong Gu
AU - Bang, Tae Yang
AU - Choi, Yeon Ho
AU - Oh, Hyeong Ill
AU - Han, Inwoo
N1 - Publisher Copyright:
© Published under Creative Commons license CC BY-SA 4.0.
PY - 2023/7
Y1 - 2023/7
N2 - This paper is written as a follow-up observations to reinterpret the radial velocity (RV) of HD 36384, where the existence of planetary systems is known to be ambiguous. In giants, it is, in general, difficult to distinguish the signals of planetary companions from those of stellar activities. Thus, known exoplanetary giant hosts are relatively rare. We, for many years, have obtained RV data in evolved stars using the high-resolution, fiber-fed Bohyunsan Observatory Echelle Spectrograph (BOES) at the Bohyunsan Optical Astronomy Observatory (BOAO). Here, we report the results of RV variations in the M giant HD 36384. We have found two significant periods of 586 d and 490 d. Considering the orbital stability, it is impossible to have two planets at so close orbits. To determine the nature of the RV variability variations, we analyze the HIPPARCOS photometric data, some indicators of stellar activities, and line profiles. A significant period of 580 d was revealed in the HIPPARCOS photometry. Ha EW variations also show a meaningful period of 582 d. Thus, the period of 586 d may be closely related to the rotational modulations and/or stellar pulsations. On the other hand, the other significant period of 490 d is interpreted as the result of the orbiting companion. Our orbital fit suggests that the companion was a planetary mass of 6.6 MJ and is located at 1.3 AU from the host.
AB - This paper is written as a follow-up observations to reinterpret the radial velocity (RV) of HD 36384, where the existence of planetary systems is known to be ambiguous. In giants, it is, in general, difficult to distinguish the signals of planetary companions from those of stellar activities. Thus, known exoplanetary giant hosts are relatively rare. We, for many years, have obtained RV data in evolved stars using the high-resolution, fiber-fed Bohyunsan Observatory Echelle Spectrograph (BOES) at the Bohyunsan Optical Astronomy Observatory (BOAO). Here, we report the results of RV variations in the M giant HD 36384. We have found two significant periods of 586 d and 490 d. Considering the orbital stability, it is impossible to have two planets at so close orbits. To determine the nature of the RV variability variations, we analyze the HIPPARCOS photometric data, some indicators of stellar activities, and line profiles. A significant period of 580 d was revealed in the HIPPARCOS photometry. Ha EW variations also show a meaningful period of 582 d. Thus, the period of 586 d may be closely related to the rotational modulations and/or stellar pulsations. On the other hand, the other significant period of 490 d is interpreted as the result of the orbiting companion. Our orbital fit suggests that the companion was a planetary mass of 6.6 MJ and is located at 1.3 AU from the host.
KW - HD 36384 — techniques
KW - individual
KW - planetary systems
KW - radial velocities — stars
KW - stars
UR - http://www.scopus.com/inward/record.url?scp=85171354047&partnerID=8YFLogxK
U2 - 10.5303/JKAS.2023.56.2.195
DO - 10.5303/JKAS.2023.56.2.195
M3 - Article
AN - SCOPUS:85171354047
SN - 1225-4614
VL - 56
SP - 195
EP - 199
JO - Journal of the Korean Astronomical Society
JF - Journal of the Korean Astronomical Society
IS - 2
ER -