The death of Vulcan: NEID reveals the planet candidate orbiting HD 26965 is stellar activity
arxiv(2024)
摘要
We revisit the long-studied radial velocity (RV) target HD26965 using recent
observations from the NASA-NSF 'NEID' precision Doppler facility. Leveraging a
suite of classical activity indicators, combined with line-by-line RV analyses,
we demonstrate that the claimed 45-day signal previously identified as a planet
candidate is most likely an activity-induced signal. Correlating the bulk
(spectrally-averaged) RV with canonical line activity indicators confirms a
multi-day 'lag' between the observed activity indicator time series and the
measured RV. When accounting for this lag, we show that much of the observed RV
signal can be removed by a linear detrending of the data. Investigating
activity at the line-by-line level, we find a depth-dependent correlation
between individual line RVs and the bulk RVs, further indicative of periodic
suppression of convective blueshift causing the observed RV variability, rather
than an orbiting planet. We conclude that the combined evidence of the activity
correlations and depth dependence is consistent with a radial velocity
signature dominated by a rotationally-modulated activity signal at a period of
∼42 days. We hypothesize that this activity signature is due to a
combination of spots and convective blueshift suppression. The tools applied in
our analysis are broadly applicable to other stars, and could help paint a more
comprehensive picture of the manifestations of stellar activity in future
Doppler RV surveys.
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要