First Observation of a Planetary Transit with the SPARC4 CCD: Improved Parameters for HATS-24b

Oliveira, Janderson M.; Martioli, Eder; Tucci-Maia, Marcelo

doi:10.3847/2515-5172/ab06c7

Cited by 4 publications

(1 citation statement)

References 28 publications

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“…For this experiment, reference values of m h = 12.25 33 and S h = 56122.30 photon/s were used. These are the magnitude and the star flux obtained for an arbitrarily selected image of the star HATS24 35 in the I-filter, acquired using the 1.6 m telescope of the Observatório Pico dos Dias. In our analysis, magnitude values ranging from 5 to 20 were considered.…”

Section: Maximum Acquisition Rates Provided By the Sparc4mentioning

confidence: 99%

Optimization of EMCCD operating parameters for the acquisitionsystem of SPARC4

Bernardes,

Martioli,

Spadoti

2021

Preprint

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We present the Optimization Method for the Electron Multiplying Charge Coupled Devices (EMCCDs) of the Acquisition System of the SPARC4 (OMASS4). The OMASS4 uses as figures of merit the signal-to-noise ratio (SNR) and the acquisition rate (AR) as a function of the operation mode of the CCDs. Three different modes of optimization are included in the OMASS4: (1) optimization of SNR only; (2) optimization of AR only; and (3) optimization of both SNR and AR simultaneously. The first two modes calculate an analytical maximization of the cost function whereas the third mode uses the bayesian optimization method to determine the optimum mode of operation. We apply the OMASS4 to find the optimum mode for observations obtained at the Pico dos Dias Observatory, Brazil, and compare the delivered modes of operation and its performance with the ones adopted by the observer. If the OMASS4 had been used as a tool to optimize the CCDs in all of these nights, it would be possible to improve their efficiency in 97.17 %, 65.08 %, and 77.66 % for the optimization modes 1, 2, and 3, respectively.

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Section: Maximum Acquisition Rates Provided By the Sparc4mentioning

confidence: 99%

Optimization of EMCCD operating parameters for the acquisitionsystem of SPARC4

Bernardes,

Martioli,

Spadoti

2021

Preprint

Self Cite

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Orbital Decay of Hot Jupiters due to Weakly Nonlinear Tidal Dissipation

Weinberg,

Davachi,

Essick

et al. 2023

ApJ

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We study tidal dissipation in hot Jupiter host stars due to the nonlinear damping of tidally driven g-modes, extending the calculations of Essick & Weinberg to a wide variety of stellar host types. This process causes the planet’s orbit to decay and has potentially important consequences for the evolution and fate of hot Jupiters. Previous studies either only accounted for linear dissipation processes or assumed that the resonantly excited primary mode becomes strongly nonlinear and breaks as it approaches the stellar center. However, the great majority of hot Jupiter systems are in the weakly nonlinear regime in which the primary mode does not break but instead excites a sea of secondary modes via three-mode interactions. We simulate these nonlinear interactions and calculate the net mode dissipation for stars that range in mass from 0.5M ⊙ ≤ M ⋆ ≤ 2.0M ⊙ and in age from the early main sequence to the subgiant phase. We find that the nonlinearly excited secondary modes can enhance the tidal dissipation by orders of magnitude compared to linear dissipation processes. For the stars with M ⋆ ≲ 1.0M ⊙ of nearly any age, we find that the orbital decay time is ≲100 Myr for orbital periods P orb ≲ 1 day. For M ⋆ ≳ 1.2M ⊙, the orbital decay time only becomes short on the subgiant branch, where it can be ≲10 Myr for P orb ≲ 2 days and result in significant transit time shifts. We discuss these results in the context of known hot Jupiter systems and examine the prospects for detecting their orbital decay with transit timing measurements.

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TESS Transit Timing of Hundreds of Hot Jupiters

Winn

2022

ApJS

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We provide a database of transit times and updated ephemerides for 382 planets based on data from the NASA Transiting Exoplanet Survey Satellite (TESS) and previously reported transit times, which were scraped from the literature in a semiautomated fashion. In total, our database contains 8667 transit-timing measurements for 382 systems. About 240 planets in the catalog are hot Jupiters (i.e., planets with mass >0.3 M Jup and period <10 days) that have been observed by TESS. The new ephemerides are useful for scheduling follow-up observations and searching for long-term period changes. WASP-12 remains the only system for which a period change is securely detected. We remark on other cases of interest, such as a few systems with suggestive (but not yet convincing) evidence for period changes, and the detection of a second transiting planet in the NGTS-11 system. The compilation of light curves, transit times, ephemerides, and timing residuals are made available online, along with the Python code that generated them (visit https://transit-timing.github.io).

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First Observation of a Planetary Transit with the SPARC4 CCD: Improved Parameters for HATS-24b

Cited by 4 publications

References 28 publications

Optimization of EMCCD operating parameters for the acquisitionsystem of SPARC4

Optimization of EMCCD operating parameters for the acquisitionsystem of SPARC4

Orbital Decay of Hot Jupiters due to Weakly Nonlinear Tidal Dissipation

TESS Transit Timing of Hundreds of Hot Jupiters

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