Issue |
A&A
Volume 668, December 2022
|
|
---|---|---|
Article Number | A110 | |
Number of page(s) | 14 | |
Section | Planets and planetary systems | |
DOI | https://doi.org/10.1051/0004-6361/202244592 | |
Published online | 13 December 2022 |
TESS search for substellar companions through pulsation timing of δ Scuti stars
I. Discovery of companions around Chang 134 and V393 Car
1
Dipartimento di Fisica e Astronomia, Università degli Studi di Padova,
Vicolo dell’Osservatorio 3,
35122
Padova, Italy
e-mail: valentina.vaulato@unige.ch
2
INAF - Osservatorio Astronomico di Padova,
Vicolo dell’Osservatorio 5,
35122
Padova, Italy
e-mail: valerio.nascimbeni@inaf.it
Received:
25
July
2022
Accepted:
2
September
2022
Early-type main-sequence pulsating stars such as δ Scuti variables are one of the least explored class of targets in the search for exoplanets. Pulsation timing (PT) is an alternative technique to the most effective search methods. It exploits the light-travel-time effect (LTTE) to infer the presence of additional massive bodies around a pulsating star by measuring a periodic phase modulation of its signal. PT has been extremely successful in discovering and characterizing stellar binaries when it was applied to high-precision light curves over long temporal baselines, such as those delivered by the Kepler mission. In favorable conditions, the sensitivity of PT can reach the planetary-mass regime; one such candidate has already been claimed. The advent of TESS, with its nearly full-sky coverage and the availability of full-frame images, opens a great opportunity to expand this field of research. In this work, we present a pilot study aimed to understand the potential of PT as applied to TESS data, which are considerably different from Kepler data in terms of photometric noise, sampling cadence, and temporal baseline. We focused on the most favorable class of δ Scuti, that is, those showing strong pulsations and very simple frequency spectra. After the development of a customized pipeline, we were able to detect candidate companions for two targets in the (sub-)stellar mass regime: Chang 134 (43 ± 5 Mjup, P ≃ 82 days) and V393 Car (≳100 Mjup, P ≳ 700 days). Our results also highlight the limiting factors of this technique and the importance of an accurate absolute time calibration for future missions such as PLATO.
Key words: stars: oscillations / stars: variables: delta Scuti / techniques: photometric / methods: data analysis / planets and satellites: detection / binaries: general
© V. Vaulato et al. 2022
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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