CHEOPS observations of TESS primary mission monotransits

Cooke, Benjamin F.; Pollacco, D.; Lendl, M.; Kuntzer, T.; Fortier, A.

doi:10.1093/mnras/staa768

Cited by 9 publications

(5 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…More than half of the known planets will have windows greater than 2 hours, which means that observations of their transits or eclipses would require significant additional observing time to have a guaranteed observations of a full transit event. Improvement of transit ephemerides will be achieved via the use of various follow-up facilities, including CHaracterizing ExOPlanets Satellite (CHEOPS) observations of TESS targets (Broeg et al 2014;Cooke et al 2020).…”

Section: Transit Ephemeris Refinementmentioning

confidence: 99%

Science Extraction from TESS Observations of Known Exoplanet Hosts

Kane

Bean

Campante

et al. 2020

PASP

View full text Add to dashboard Cite

Where a licence is displayed above, please note the terms and conditions of the licence govern your use of this document. When citing, please reference the published version. Take down policy While the University of Birmingham exercises care and attention in making items available there are rare occasions when an item has been uploaded in error or has been deemed to be commercially or otherwise sensitive.

show abstract

Section: Transit Ephemeris Refinementmentioning

confidence: 99%

Science Extraction from TESS Observations of Known Exoplanet Hosts

Kane

Bean

Campante

et al. 2020

PASP

View full text Add to dashboard Cite

show abstract

“…This set of period aliases P ∈ (t tr,2 − t tr,1 )/{1, 2, 3, • • • , N max } are bounded at the long end by the temporal distance between the transits P max = (t 2 − t 1 ) and at the short end by the non-detection of subsequent transits in the TESS data. Such cases are expected to be commonplace during the TESS extended mission, as planets that were observed Article number, page 1 of 18 arXiv: 2203.03194v2 [astro-ph.EP] 12 Mar 2022 to transit once in the primary mission transit again (Cooke et al 2020(Cooke et al , 2021.…”

Section: Introductionmentioning

confidence: 99%

Uncovering the true periods of the young sub-Neptunes orbiting TOI-2076

Osborn

Bonfanti

Hedges

et al. 2022

A&A

View full text Add to dashboard Cite

Context. TOI-2076 is a transiting three-planet system of sub-Neptunes orbiting a bright (G = 8.9 mag), young (340 ± 80 Myr) K-type star. Although a validated planetary system, the orbits of the two outer planets were unconstrained as only two non-consecutive transits were seen in TESS photometry. This left 11 and 7 possible period aliases for each. Aims. To reveal the true orbits of these two long-period planets, precise photometry targeted on the highest-probability period aliases is required. Long-term monitoring of transits in multi-planet systems can also help constrain planetary masses through TTV measurements. Methods. We used the MonoTools package to determine which aliases to follow, and then performed space-based and ground-based photometric follow-up of TOI-2076 c and d with CHEOPS, SAINT-EX, and LCO telescopes. Results. CHEOPS observations revealed a clear detection for TOI-2076 c at P = 21.01538 +0.00084 −0.00074 d, and allowed us to rule out three of the most likely period aliases for TOI-2076 d. Ground-based photometry further enabled us to rule out remaining aliases and confirm the P = 35.12537 ± 0.00067 d alias. These observations also improved the radius precision of all three sub-Neptunes to 2.518 ± 0.036, 3.497 ± 0.043, and 3.232 ± 0.063 R ⊕ . Our observations also revealed a clear anti-correlated TTV signal between planets b and c likely caused by their proximity to the 2:1 resonance, while planets c and d appear close to a 5:3 period commensurability, although model degeneracy meant we were unable to retrieve robust TTV masses. Their inflated radii, likely due to extended H-He atmospheres, combined with low insolation makes all three planets excellent candidates for future comparative transmission spectroscopy with JWST.

show abstract

“…Considering the distribution of planets detected by the transit technique, we are far from completion. Other peculiar cases that could be tested and simulated in future works include, for example, transits showing timing variations (TTV, Holman & Murray 2005, Nascimbeni et al 2011, Malavolta et al 2017, monotransits (Cooke et al 2020), multi-planetary systems, or small planets with orbital periods longer than 40 days, that is, temperate terrestrial planets such as those around the dwarf star TRAPPIST-1 (Gillon et al 2017). Indeed, PLATO's top-level science requirements are focused on habitable planets, therefore it would be interesting to test the algorithms also on more temperate Earth-like planets.…”

Section: Discussionmentioning

confidence: 99%

Discovering planets with PLATO: Comparison of algorithms for stellar activity filtering

Canocchi

Malavolta

Pagano

et al. 2023

A&A

View full text Add to dashboard Cite

Context. To date, stellar activity is one of the main limitations in detecting small exoplanets via the transit photometry technique. Since this activity is enhanced in young stars, traditional filtering algorithms may severely underperform in attempting to detect such exoplanets, with shallow transits often obscured by the photometric modulation of the light curve. Aims. This paper aims to compare the relative performances of four algorithms developed by independent research groups specifically for the filtering of activity in the light curves of young active stars, prior to the search for planetary transit signals: Notch and LOCoR (N&L), Young Stars Detrending (YSD), K2 Systematics Correction (K2SC), and VARLET. Our comparison also includes the two best-performing algorithms implemented in the Wōtan package: Tukey's biweight and Huber spline algorithms. Methods. For this purpose, we performed a series of injection-retrieval tests of planetary transits of different types, from Jupiter down to Earth-sized planets, moving both on circular and eccentric orbits. These experiments were carried out over a set of 100 realistically simulated light curves of both quiet and active solar-like stars (i.e., F and G types) that will be observed by the ESA Planetary Transits and Oscillations of stars (PLATO) space telescope, starting 2026. Results. From the experiments for transit detections, we found that N&L is the best choice in many cases, since it misses the lowest number of transits. However, this algorithm is shown to underperform when the planetary orbital period closely matches the stellar rotation period, especially in the case of small planets for which the biweight and VARLET algorithms work better. Moreover, for light curves with a large number of data-points, the combined results of two algorithms, YSD and Huber spline, yield the highest recovery percentage. Filtering algorithms allow us to obtain a very precise estimate of the orbital period and the mid-transit time of the detected planets, while the planet-to-star radius is underestimated most of the time, especially in cases of grazing transits or eccentric orbits. A refined filtering that takes into account the presence of the planet is thus compulsory for proper planetary characterization analyses.

show abstract

CHEOPS observations of TESS primary mission monotransits

Cited by 9 publications

References 21 publications

Science Extraction from TESS Observations of Known Exoplanet Hosts

Science Extraction from TESS Observations of Known Exoplanet Hosts

Uncovering the true periods of the young sub-Neptunes orbiting TOI-2076

Discovering planets with PLATO: Comparison of algorithms for stellar activity filtering

Contact Info

Product

Resources

About