TY - JOUR

T1 - The impact of photospheric brightness field on exoplanetary transit timings and the TTV excess of HD 189733 b

AU - Baluev, Roman V.

PY - 2022/1/1

Y1 - 2022/1/1

N2 - We consider the issue of excessive TTV noise observed for the exoplanet HD 189733 b. Trying to explain it through the host star photospheric activity, we model the stellar surface brightness as a random field, then characterize statistical properties of the resulting transit signal perturbation and compute individual corrections to transit timings uncertainties. We find that possible effect of the photospheric brightness field can explain only a minor portion (∼10 s) of the observed (∼70 s) TTV excess of HD 189733, suggesting that the rest should be attributed to other sources. Regarding the photospheric pattern, we place an upper limit of ∼0.01 on the combination ϵcellrcell, where ϵcell is the relative magnitude of brightness variations, and rcell is the geometric cellularity scale (relative to star radius).

AB - We consider the issue of excessive TTV noise observed for the exoplanet HD 189733 b. Trying to explain it through the host star photospheric activity, we model the stellar surface brightness as a random field, then characterize statistical properties of the resulting transit signal perturbation and compute individual corrections to transit timings uncertainties. We find that possible effect of the photospheric brightness field can explain only a minor portion (∼10 s) of the observed (∼70 s) TTV excess of HD 189733, suggesting that the rest should be attributed to other sources. Regarding the photospheric pattern, we place an upper limit of ∼0.01 on the combination ϵcellrcell, where ϵcell is the relative magnitude of brightness variations, and rcell is the geometric cellularity scale (relative to star radius).

KW - HD 189733

KW - activity

KW - data analysis

KW - individual

KW - methods

KW - photometric

KW - planetary systems

KW - stars

KW - statistical

KW - techniques

KW - I.

KW - CONFIRMATION

KW - GRANULATION

KW - STELLAR ACTIVITY

KW - methods: statistical

KW - WASP-12

KW - RADIAL-VELOCITY

KW - stars: activity

KW - ANALYSIS TOOL

KW - PLANETS

KW - methods: data analysis

KW - techniques: photometric

KW - TIME

KW - PARAMETERS

KW - stars: individual: HD 189733

UR - https://www.mendeley.com/catalogue/697dddf4-a89e-3285-93d8-7f01a44e117c/

UR - http://www.scopus.com/inward/record.url?scp=85121266432&partnerID=8YFLogxK

U2 - 10.1093/mnras/stab3073

DO - 10.1093/mnras/stab3073

M3 - Article

VL - 509

SP - 1048

EP - 1061

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 1

ER -