How Complete Are Surveys for Nearby Transiting Hot Jupiters?

Abstract

Hot Jupiters are a rare and interesting outcome of planet formation. Although more than 500 hot Jupiters (HJs) are known, most of them were discovered by a heterogeneous collection of surveys with selection biases that are difficult to quantify. Currently, our best knowledge of HJ demographics around FGK stars comes from the sample of ≈40 objects detected by the Kepler mission, which have a well-quantified selection function. Using the Kepler results, we simulate the characteristics of the population of nearby transiting HJs. A comparison between the known sample of nearby HJs and simulated magnitude-limited samples leads to four conclusions. (1) The known sample of HJs appears to be ≈75% complete for stars brighter than Gaia G ≤ 10.5, falling to ≲50% for G ≤ 12. (2) There are probably a few undiscovered HJs with host stars brighter than G ≈ 10 located within 10° of the Galactic plane. (3) The period and radius distributions of HJs may differ for F-type hosts (which dominate the nearby sample) and G-type hosts (which dominate the Kepler sample). (4) To obtain a magnitude-limited sample of HJs that is larger than the Kepler sample by an order of magnitude, the limiting magnitude should be approximately G ≈ 12.5. This magnitude limit is within the range for which NASA’s Transiting Exoplanet Survey Satellite can easily detect HJs, presenting the opportunity to greatly expand our knowledge of hot-Jupiter demographics.

The TESS Grand Unified Hot Jupiter Survey. I. Ten TESS Planets

“…This will require more observations to detect and confirm new planets (the "numerator" of demographic calculations) as well as a detailed examination of the TESS selection function and survey characteristics (the "denominator"). Based on the forecast of Yee et al (2021), to assemble a sample of 400 hot Jupiters (an orderof-magnitude more planets than the Kepler sample), a magnitude-limited survey would need to be complete down to G = 12.5. The ten planets described here, along with the other new TESS hot Jupiters that have been described in the literature (e.g., Rodriguez et al 2019;Zhou et al 2019;Brahm et al 2020;Davis et al 2020;Nielsen et al 2020;Ikwut-Ukwa et al 2021;Rodriguez et al 2021;Sha et al 2021;Wong et al 2021;Knudstrup et al 2022;Rodriguez et al 2022) are steps toward realizing the promise of TESS for hot Jupiter demographics.…”

“…As a nearly all-sky space-based photometric survey that dwells on a given star field for 27 days at a time, the TESS survey should be able to identify nearly all of the hot Jupiters that transit stars which are bright and nearby enough for detailed follow-up observations and characterization (Zhou et al 2019). Simulations have predicted that the TESS planet catalog will eventually contain ≈400 hot Jupiters around FGK stars brighter than G = 12.5 (Yee et al 2021). Such a sample would be an order of magnitude larger than the sample of 40 hot Jupiters found during the original Kepler mission, which is the largest statistically useful sample of such planets currently available.…”

Another Shipment of Six Short-Period Giant Planets from TESS

“…Even in the ∼4 years since its launch, TESS has discovered over 200 planets 9 , of which 47 are above 0.4 M J , nearly 10% of the known transiting giant planet population (See Figure 6). As multiple efforts, including ours, continue to confirm and characterize new transiting giant planets, it will lead to a magnitudecomplete, self-consistent sample of planet properties (Zhou et al 2019;Yee et al 2021).…”

The Discovery of a Planetary Companion Interior to Hot Jupiter WASP-132 b

“…The Transiting Exoplanet Survey Satellite (TESS; Ricker 2015) is well suited to the discovery of hot Jupiters and potential nearby companions, as its almost-all-sky coverage is expected to observe nearly every known hot Jupiter system and discover hundreds or thousands more (Sullivan et al 2015; Barclay et al 2018). This is particularly important, since the hot Jupiter sample is currently heterogeneous and incomplete (Yee et al 2021). In addition, TESS has the photometric precision to identify smaller planets down to ∼0.7 R ⊕ (e.g., Kostov et al 2019b;Gilbert et al 2020;Silverstein et al 2022).…”