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Transiting exoplanets orbiting young nearby stars are ideal laboratories for testing theories of planet formation and evolution. However, to date only a handful of stars with age, submitted to MNRAS

Funding: TGW, ACC, and KH acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant ST/R003203/1. We present the discovery of two exoplanets transiting TOI-836 (TIC 440887364) using data from TESS Sector 11 and Sector 38. TOI-836 is a bright (T = 8.5 mag), high proper motion (∼200 mas yr−1), low metallicity ([Fe/H]≈−0.28) K-dwarf with a mass of 0.68 ± 0.05 M⊙ and a radius of 0.67 ± 0.01 R⊙. We obtain photometric follow-up observations with a variety of facilities, and we use these data-sets to determine that the inner planet, TOI-836 b, is a 1.70 ± 0.07 R⊕ super-Earth in a 3.82 day orbit, placing it directly within the so-called ‘radius valley’. The outer planet, TOI-836 c, is a 2.59 ± 0.09 R⊕ mini-Neptune in an 8.60 day orbit. Radial velocity measurements reveal that TOI-836 b has a mass of 4.5 ± 0.9 M⊕, while TOI-836 c has a mass of 9.6 ± 2.6 M⊕. Photometric observations show Transit Timing Variations (TTVs) on the order of 20 minutes for TOI-836 c, although there are no detectable TTVs for TOI-836 b. The TTVs of planet TOI-836 c may be caused by an undetected exterior planet. Publisher PDF

HD$\,$172555 is a young ($\sim$20$\,$Myr) A7V star surrounded by a 10$\,$au wide debris disk suspected to be replenished partly by collisions between large planetesimals. Small evaporating transiting bodies, exocomets, have also been detected in this system by spectroscopy. After $\beta\,$Pictoris, this is another example of a system possibly witnessing a phase of heavy bombardment of planetesimals. In such system, small bodies trace dynamical evolution processes. We aim at constraining their dust content by using transit photometry. We performed a 2-day-long photometric monitoring of HD$\,$172555 with the CHEOPS space telescope in order to detect shallow transits of exocomets with a typical expected duration of a few hours. The large oscillations in the lightcurve indicate that HD$\,$172555 is a $\delta\,$Scuti pulsating star. Once removing those dominating oscillations, we find a hint for a transient absorption. If fitted with an exocomet transit model, it corresponds to an evaporating body passing near the star at a distance of $6.8\pm1.4\,$R$_\star$ (or $0.05\pm 0.01\,$au) with a radius of 2.5 km. These properties are comparable to those of the exocomets already found in this system using spectroscopy, as well as those found in the $\beta\,$Pic system. The nuclei of solar system's Jupiter family comets, with radii of 2-6$\,$km, are also comparable in size. This is the first evidence for an exocomet photometric transit detection in the young system of HD$\,$172555., Comment: 12 pages, 10 figures, 5 tables, accepted for publication in A&A

GJ 367 is a bright (V $\approx$ 10.2) M1 V star that has been recently found to host a transiting ultra-short period sub-Earth on a 7.7 hr orbit. With the aim of improving the planetary mass and radius and unveiling the inner architecture of the system, we performed an intensive radial velocity follow-up campaign with the HARPS spectrograph -- collecting 371 high-precision measurements over a baseline of nearly 3 years -- and combined our Doppler measurements with new TESS observations from sectors 35 and 36. We found that GJ 367 b has a mass of $M_\mathrm{b}$ = 0.633 $\pm$ 0.050 M$_{\oplus}$ and a radius of $R_\mathrm{b}$ = 0.699 $\pm$ 0.024 R$_{\oplus}$, corresponding to precisions of 8% and 3.4%, respectively. This implies a planetary bulk density of $\rho_\mathrm{b}$ = 10.2 $\pm$ 1.3 g cm$^{-3}$, i.e., 85% higher than Earth's density. We revealed the presence of two additional non transiting low-mass companions with orbital periods of $\sim$11.5 and 34 days and minimum masses of $M_\mathrm{c}\sin{i_\mathrm{c}}$ = 4.13 $\pm$ 0.36 M$_{\oplus}$ and $M_\mathrm{d}\sin{i_\mathrm{d}}$ = 6.03 $\pm$ 0.49 M$_{\oplus}$, respectively, which lie close to the 3:1 mean motion commensurability. GJ 367 b joins the small class of high-density planets, namely the class of super-Mercuries, being the densest ultra-short period small planet known to date. Thanks to our precise mass and radius estimates, we explored the potential internal composition and structure of GJ 367 b, and found that it is expected to have an iron core with a mass fraction of 0.91$^{+0.07}_{-0.23}$. How this iron core is formed and how such a high density is reached is still not clear, and we discuss the possible pathways of formation of such a small ultra-dense planet., Comment: 28 pages, 11 figures. Accepted for publication in ApJL

Full list of authors: Murgas, F.; Nowak, G.; Masseron, T.; Parviainen, H.; Luque, R.; Pallé, E.; Korth, J.; Carleo, I.; Csizmadia, S.; Esparza-Borges, E.; Alqasim, A.; Cochran, W. D.; Dai, F.; Deeg, H. J.; Gandolfi, D.; Goffo, E.; Kabáth, P.; Lam, K. W. F.; Livingston, J.; Muresan, A.; Osborne, H. L. M.; Persson, C. M.; Serrano, L. M.; Smith, A. M. S.; Van Eylen, V.; Orell-Miquel, J.; Hinkel, N. R.; Galán, D.; Puig-Subirà, M.; Stangret, M.; Fukui, A.; Kagetani, T.; Narita, N.; Ciardi, D.R.; Boyle, A.W.; Ziegler, C.; Briceño, C.; Law, N.; Mann, A.W.; Jenkins, J.M.; Latham, D.W.; Quinn, S.N.; Ricker, G.; Seager, S.; Shporer, A.; Ting, E. B.; Vanderspek, R.; Winn, J. N.-- This is an 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., Context. Ultra-short-period (USP) planets are defined as planets with orbital periods shorter than one day. This type of planets is rare, highly irradiated, and interesting because their formation history is unknown. Aims. We aim to obtain precise mass and radius measurements to confirm the planetary nature of a USP candidate found by the Transiting Exoplanet Survey Satellite (TESS). These parameters can provide insights into the bulk composition of the planet candidate and help to place constraints on its formation history. Methods. We used TESS light curves and HARPS-N spectrograph radial velocity measurements to establish the physical properties of the transiting exoplanet candidate found around the star HD 20329 (TOI-4524). We performed a joint fit of the light curves and radial velocity time series to measure the mass, radius, and orbital parameters of the candidate. Results. We confirm and characterize HD 20329b, a USP planet transiting a solar-type star. The host star (HD 20329, V = 8.74 mag, J = 7.5 mag) is characterized by its G5 spectral type with M∗ = 0.90 ± 0.05 M⊙, R∗ = 1.13 ± 0.02 R⊙, and Teff = 5596 ± 50 K; it is located at a distance d = 63.68 ± 0.29 pc. By jointly fitting the available TESS transit light curves and follow-up radial velocity measurements, we find an orbital period of 0.9261 ± (0.5 ×10-4) days, a planetary radius of 1.72 ± 0.07 R∗, and a mass of 7.42 ± 1.09 M∗, implying a mean density of ρp = 8.06 ± 1.53 g cm-3. HD 20329b joins the ~30 currently known USP planets with radius and Doppler mass measurements. © F. Murgas et al. 2022., T.M. acknowledges financial support from the Spanish Ministry of Science and Innovation (MICINN) through the Spanish State Research Agency, under the Severo Ochoa Program 2020-2023 (CEX2019-000920-S) as well as support from the ACIISI, Consejería de Economía, Conocimiento y Empleo del Gobierno de Canarias and the European Regional Development Fund (ERDF) under grant with reference PROID2021010128. R.L. acknowledges funding from University of La Laguna through the Margarita Salas Fellowship from the Spanish Ministry of Universities ref. UNI/551/2021-May 26 under the EU Next Generation funds and financial support from the Spanish Ministerio de Ciencia e Innovación, through project PID2019-109522GB-C52, and the Centre of Excellence “Severo Ochoa” award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). PK acknolwedges the support from grant LTT-20015. K.W.F.L. was supported by Deutsche Forschungsgemeinschaft grants RA714/14-1 within the DFG Schwerpunkt SPP 1992, Exploring the Diversity of Extrasolar Planets. HJD acknowledges support from the Spanish Research Agency of the Ministry of Science and Innovation (AEI-MICINN) under the grant PID2019-107061GB-C66, DOI: 10.13039/501100011033. C.M.P. and J.K. gratefully acknowledge the support of the Swedish National Space Agency (DNR 65/19 2020-00104). This paper includes data collected by the TESS mission, which are publicly available from the Mikulski Archive for Space Telescopes (MAST). Funding for the TESS mission is provided by NASA’s Science Mission directorate. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. We acknowledge the use of public TESS data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. This research has made use of the Exoplanet Follow-up Observation Program website, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This publication makes use of data products from the AAVSO Photometric All Sky Survey (APASS). Funded by the Robert Martin Ayers Sciences Fund and the National Science Foundation. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This work made use of tpfplotter by J. Lillo-Box (publicly available in www.github.com/jlillo/tpfplotter), which also made use of the python packages astropy, lightkurve, matplotlib and numpy. This work is partly supported by JSPS KAKENHI Grant Numbers JP17H04574, JP18H05442, JST CREST Grant Number JPMJCR1761, and the Astrobiology Center of National Institutes of Natural Sciences (NINS) (Grant Number AB031010). This paper is based on observations made with the MuSCAT2 instrument, developed by ABC, at Telescopio Carlos Sánchez operated on the island of Tenerife by the IAC in the Spanish Observatorio del Teide.

Here we report large-amplitude transit timing variations (TTVs) for AU Microcopii b and c as detected in combined TESS (2018, 2020) and CHEOPS (2020, 2021) transit observations. AU Mic is a young planetary system with a debris disk and two transiting warm Neptunes. A TTV on the order of several minutes was previously reported for AU Mic b, which was suggested to be an outcome of mutual perturbations between the planets in the system. In 2021, we observed AU Mic b (five transits) and c (three transits) with the CHEOPS space telescope to follow-up the TTV of AU Mic b and possibly detect a TTV for AU Mic c. When analyzing TESS and CHEOPS 2020a 2021 measurements together, we find that a prominent TTV emerges with a full span of a ¥23 min between the two TTV extrema. Assuming that the period change results from a periodic process a such as mutual perturbationsa we demonstrate that the times of transits in the summer of 2022 are expected to be 30a 85 min later than predicted by the available linear ephemeris., This work was supported by FCT – Fundação para a Ciência e a Tecnologia through national funds and by FEDER through COMPETE2020 – Programa Operacional Competitividade e Internacionalizacão by these grants: UID/FIS/04434/2019, UIDB/04434/2020, UIDP/04434/2020, PTDC/FIS-AST/32113/2017 and POCI-01-0145-FEDER-032113, PTDC/FIS-AST/28953/2017 and POCI-01-0145-FEDER-028953, PTDC/FIS-AST/28987/2017 and POCI-01-0145-FEDER-028987, O.D.S.D. is supported in the form of work contract (DL 57/2016/CP1364/CT0004) funded by national funds through FCT. B.-O.D. acknowledges support from the Swiss National Science Foundation (PP00P2-190080). This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (project FOUR ACES grant agreement No 724427). It has also been carried out in the frame of the National Centre for Competence in Research PlanetS supported by the Swiss National Science Foundation (SNSF). D.E. acknowledges financial support from the Swiss National Science Foundation for project 200021_200726. L.D. is an F.R.S.-FNRS Postdoctoral Researcher. M.F. and C.M.P. gratefully acknowledge the support of the Swedish National Space Agency (DNR 65/19, 174/18). M.G. is an F.R.S.-FNRS Senior Research Associate. S.H. gratefully acknowledges CNES funding through the grant 837319. K.G.I. is the ESA CHEOPS Project Scientist and is responsible for the ESA CHEOPS Guest Observers Programme. She does not participate in, or contribute to, the definition of the Guaranteed Time Programme of the CHEOPS mission through which observations described in this Letter have been taken, nor to any aspect of target selection for the programme. This work was granted access to the HPC resources of MesoPSL financed by the Region Ile de France and the project Equip@Meso (reference ANR-10-EQPX-29-01) of the programme Investissements d’Avenir supervised by the Agence Nationale pour la Recherche. P.M. acknowledges support from STFC research grant number ST/M001040/1. Acknowledges support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grant PGC2018-098153-B-C33, as well as the support of the Generalitat de Catalunya/CERCA programme. S.G.S. acknowledges support from FCT through FCT contract nr. CEECIND/00826/2018 and POPH/FSE (EC).

Full list of authors: Kabath, Petr; Chaturvedi, Priyanka; MacQueen, Phillip J.; Skarka, Marek; Subjak, Jan; Esposito, Massimilliano; Cochran, William D.; Bellomo, Salvatore E.; Karjalainen, Raine; Guenther, Eike W.; Endl, Michael; Csizmadia, Szilard; Karjalainen, Marie; Hatzes, Artie; Zak, Jiri; Gandolfi, Davide; Boffin, Henri M. J.; Vines, Jose, I; Livingston, John H.; Garcia, Rafael A.; Mathur, Savita; Gonzalez-Cuesta, Lucia; Blazek, Martin; Caldwell, Douglas A.; Colon, Knicole D.; Deeg, Hans; Erikson, Anders; Van Eylen, Vincent; Fong, William; Fridlund, Malcolm; Fukui, Akihiko; Furesz, Gabor; Goeke, Robert F.; Goffo, Elisa; Howell, Steve; Jenkins, Jon M.; Klagyivik, Peter; Korth, Judith; Latham, David W.; Luque, Rafael; Moldovan, Dan; Murgas, Felipe; Narita, Norio; Orell-Miquel, Jaume; Palle, Enric; Parviainen, Hannu; Persson, Carina M.; Reed, Phillip A.; Redfield, Seth; Ricker, George R.; Seager, Sara; Serrano, Luisa Maria; Shporer, Avi; Smith, Alexis M. S.; Watanabe, Noriharu; Winn, Joshua N.; KESPRINT Team., We present the confirmation and characterization of three hot Jupiters, TOI-1181b, TOI-1516b, and TOI-2046b, discovered by the TESS space mission. The reported hot Jupiters have orbital periods between 1.4 and 2.05 d. The masses of the three planets are 1.18 ± 0.14 MJ, 3.16 ± 0.12 MJ, and 2.30 ± 0.28 MJ, for TOI-1181b, TOI-1516b, and TOI-2046b, respectively. The stellar host of TOI-1181b is a F9IV star, whereas TOI-1516b and TOI-2046b orbit F main sequence host stars. The ages of the first two systems are in the range of 2–5 Gyrs. However, TOI-2046 is among the few youngest known planetary systems hosting a hot Jupiter, with an age estimate of 100–400 Myrs. The main instruments used for the radial velocity follow-up of these three planets are located at Ondřejov, Tautenburg, and McDonald Observatory, and all three are mounted on 2–3 m aperture telescopes, demonstrating that mid-aperture telescope networks can play a substantial role in the follow-up of gas giants discovered by TESS and in the future by PLATO. © 2022 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society, This work is done under the framework of the KESPRINT collaboration (http://www.kesprint.science). KESPRINT is an international consortium devoted to the characterization and research of exoplanets discovered with space-based missions. This work is based on data sets obtained with the Perek 2-m telescope. PK, JS, MS, RK, and MB are acknowledging the support by Inter-transfer grant no LTT-20015. MK acknowledges the support from ESA-PRODEX PEA4000127913. PK and JS acknowledge a travel budget from ERASMUS + grant 2020-1-CZ01-KA203-078200. HB’s mobility was funded under: MŠMT – CZ.02.2.69/0.0/0.0/18_053/0016972 Podpora mezinárodní spolupráce v astronomii. PC acknowledges the generous support from Deutsche Forschungsgemeinschaft (DFG) of the grant CH 2636/1-1. PR acknowledges support from National Science Foundations (NSF) grant No. 1952545. This work was generously supported by the Thüringer Ministerium für Wirtschaft, Wissenschaft und Digitale Gesellschaft. We acknowledge the use of public TESS data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. JIV acknowledges support of CONICYT-PFCHA/Doctorado Nacional-21191829. This work is partly supported by JSPS KAKENHI Grant Number JP20K14518. JK gratefully acknowledge the support of the Swedish National Space Agency (SNSA; DNR 2020-00104). HD acknowledges support from the Spanish Research Agency of the Ministry of Science and Innovation (AEI-MICINN) under grant PID2019-107061GB-C66, DOI: 10.13039/501100011033. RL acknowledges financial support from the Spanish Ministerio de Ciencia e Innovación, through project PID2019-109522GB-C52, and the Centre of Excellence ’Severo Ochoa’ award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC; https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This is University of Texas Center for Planetary Systems Habitability contribution #0054. LGC acknowledges support from grant FPI-SO from the Spanish Ministry of Economy and Competitiveness (MINECO) (research project SEV-2015-0548-17-2 and predoctoral contract BES-2017-082610). SM acknowledges support by the Spanish Ministry of Science and Innovation with the Ramon y Cajal fellowship number RYC-2015-17697 and the grant number PID2019-107187GB-I00. RAG acknowledges the support from PLATO and GOLF CNES grants. This paper includes data collected with the TESS mission, obtained from the MAST data archive at the Space Telescope Science Institute (STScI). Funding for the TESS mission is provided by the NASA Explorer Program. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. Observations in the paper made use of the NN-EXPLORE Exoplanet and Stellar Speckle Imager (NESSI). NESSI was funded by the NASA Exoplanet Exploration Program and the NASA Ames Research Center. NESSI was built at the Ames Research Center by Steve B. Howell, Nic Scott, Elliott P. Horch, and Emmett Quigley. The authors are honored to be permitted to conduct observations on Iolkam Du’ag (Kitt Peak), a mountain within the Tohono O’odham Nation with particular significance to the Tohono O’odham people. This work is partly supported by JSPS KAKENHI Grant Number JP17H04574 and JP18H05439, JST PRESTO Grant Number JPMJPR1775, the Astrobiology Center of National Institutes of Natural Sciences (NINS; Grant Number AB031010). This article is based on observations made with the MuSCAT2 instrument, developed by ABC, at Telescopio Carlos Sánchez operated on the island of Tenerife by the IAC in the Spanish Observatorio del Teide. Observations in the paper made use of the High-Resolution Imaging instrument ‘Alopeke. ‘Alopeke was funded by the NASA Exoplanet Exploration Program and built at the NASA Ames Research Center by Steve B. Howell, Nic Scott, Elliott P. Horch, and Emmett Quigley. ‘Alopeke was mounted on the Gemini North telescope of the international Gemini Observatory, a program of NSF’s NOIRLab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation on behalf of the Gemini partnership: the National Science Foundation (United States), National Research Council (Canada), Agencia Nacional de Investigación y Desarrollo (Chile), Ministerio de Ciencia, Tecnología e Innovación (Argentina), Ministério da Ciência, Tecnologia, Inovações e Comunicações (Brazil), and Korea Astronomy and Space Science Institute (Republic of Korea).

K2-139 b is a warm Jupiter with an orbital period of 28.4 d, but only three transits of this system have previously been observed, in the long-cadence mode of K2, limiting the precision with which the orbital period can be determined, and future transits predicted. We report photometric observations of four transits of K2-139 b with ESA's CHaracterising ExOPlanet Satellite (CHEOPS), conducted with the goal of measuring the orbital obliquity via spot-crossing events. We jointly fit these CHEOPS data alongside the three previously-published transits from the K2 mission, considerably increasing the precision of the ephemeris of K2-139 b. The transit times for this system can now be predicted for the next decade with a $1 \sigma$ precision less than 10 minutes, compared to over one hour previously, allowing the efficient scheduling of observations with Ariel. We detect no significant deviation from a linear ephemeris, allowing us to exclude the presence of a massive outer planet orbiting with a period less than 150 d, or a brown dwarf with a period less than one year. We also determine the scaled semi-major axis, the impact parameter, and the stellar limb-darkening with improved precision. This is driven by the shorter cadence of the CHEOPS observations compared to that of K2, and validates the sub-exposure technique used for analysing long-cadence photometry. Finally, we note that the stellar spot configuration has changed from the epoch of the K2 observations; unlike the K2 transits, we detect no evidence of spot-crossing events in the CHEOPS data., Comment: 13 pages, 5 figures. Accepted for publication in The Astronomical Journal

Full list of authors: Wilson, Thomas G.; Goffo, Elisa; Alibert, Yann; Gandolfi, Davide; Bonfanti, Andrea; Persson, Carina M.; Collier Cameron, Andrew; Fridlund, Malcolm; Fossati, Luca; Korth, Judith; Benz, Willy; Deline, Adrien; Florén, Hans-Gustav; Guterman, Pascal; Adibekyan, Vardan; Hooton, Matthew J.; Hoyer, Sergio; Leleu, Adrien; Mustill, Alexander James; Salmon, Sébastien; Sousa, Sérgio G.; Suarez, Olga; Abe, Lyu; Agabi, Abdelkrim; Alonso, Roi; Anglada, Guillem; Asquier, Joel; Bárczy, Tamas; Barrado Navascues, David; Barros, Susana C. C.; Baumjohann, Wolfgang; Beck, Mathias; Beck, Thomas; Billot, Nicolas; Bonfils, Xavier; Brandeker, Alexis; Broeg, Christopher; Bryant, Edward M.; Burleigh, Matthew R.; Buttu, Marco; Cabrera, Juan; Charnoz, Sébastien; Ciardi, David R.; Cloutier, Ryan; Cochran, William D.; Collins, Karen A.; Colón, Knicole D.; Crouzet, Nicolas; Csizmadia, Szilard; Davies, Melvyn B.; Deleuil, Magali; Delrez, Laetitia; Demangeon, Olivier; Demory, Brice-Olivier; Dragomir, Diana; Dransfield, Georgina; Ehrenreich, David; Erikson, Anders; Fortier, Andrea; Gan, Tianjun; Gill, Samuel; Gillon, Michaël; Gnilka, Crystal L.; Grieves, Nolan; Grziwa, Sascha; Güdel, Manuel; Guillot, Tristan; Haldemann, Jonas; Heng, Kevin; Horne, Keith; Howell, Steve B.; Isaak, Kate G.; Jenkins, Jon M.; Jensen, Eric L. N.; Kiss, Laszlo; Lacedelli, Gaia; Lam, Kristine; Laskar, Jacques; Latham, David W.; Lecavelier des Etangs, Alain; Lendl, Monika; Lester, Kathryn V.; Levine, Alan M.; Livingston, John; Lovis, Christophe; Luque, Rafael; Magrin, Demetrio; Marie-Sainte, Wenceslas; Maxted, Pierre F. L.; Mayo, Andrew W.; McLean, Brian; Mecina, Marko; Mékarnia, Djamel; Nascimbeni, Valerio; Nielsen, Louise D.; Olofsson, Göran; Osborn, Hugh P.; Osborne, Hannah L. M.; Ottensamer, Roland; Pagano, Isabella; Pallé, Enric; Peter, Gisbert; Piotto, Giampaolo; Pollacco, Don; Queloz, Didier; Ragazzoni, Roberto; Rando, Nicola; Rauer, Heike; Redfield, Seth; Ribas, Ignasi; Ricker, George R.; Rieder, Martin; Santos, Nuno C.; Scandariato, Gaetano; Schmider, François-Xavier; Schwarz, Richard P.; Scott, Nicholas J.; Seager, Sara; Ségransan, Damien; Serrano, Luisa Maria; Simon, Attila E.; Smith, Alexis M. S.; Steller, Manfred; Stockdale, Chris; Szabó, Gyula; Thomas, Nicolas; Ting, Eric B.; Triaud, Amaury H. M. J.; Udry, Stéphane; Van Eylen, Vincent; Van Grootel, Valérie; Vanderspek, Roland K.; Viotto, Valentina; Walton, Nicholas; Winn, Joshua N., We report the discovery and characterization of a pair of sub-Neptunes transiting the bright K-dwarf TOI-1064 (TIC 79748331), initially detected in the Transiting Exoplanet Survey Satellite (TESS) photometry. To characterize the system, we performed and retrieved the CHaracterising ExOPlanets Satellite (CHEOPS), TESS, and ground-based photometry, the High Accuracy Radial velocity Planet Searcher (HARPS) high-resolution spectroscopy, and Gemini speckle imaging. We characterize the host star and determine Teff,⋆=4734±67K⁠, R⋆=0.726±0.007R⊙⁠, and M⋆=0.748±0.032M⊙⁠. We present a novel detrending method based on point spread function shape-change modelling and demonstrate its suitability to correct flux variations in CHEOPS data. We confirm the planetary nature of both bodies and find that TOI-1064 b has an orbital period of Pb = 6.44387 ± 0.00003 d, a radius of Rb = 2.59 ± 0.04 R⊕, and a mass of Mb=13.5+1.7−1.8 M⊕, whilst TOI-1064 c has an orbital period of Pc=12.22657+0.00005−0.00004 d, a radius of Rc = 2.65 ± 0.04 R⊕, and a 3σ upper mass limit of 8.5 M⊕. From the high-precision photometry we obtain radius uncertainties of ∼1.6 per cent, allowing us to conduct internal structure and atmospheric escape modelling. TOI-1064 b is one of the densest, well-characterized sub-Neptunes, with a tenuous atmosphere that can be explained by the loss of a primordial envelope following migration through the protoplanetary disc. It is likely that TOI-1064 c has an extended atmosphere due to the tentative low density, however further radial velocities are needed to confirm this scenario and the similar radii, different masses nature of this system. The high-precision data and modelling of TOI-1064 b are important for planets in this region of mass–radius space, and it allow us to identify a trend in bulk density–stellar metallicity for massive sub-Neptunes that may hint at the formation of this population of planets. © The Author(s) 2022., This study is based on observations made with ESO Telescopes at the La Silla Observatory under program ID 1102.C-0923. CHEOPS is an ESA mission in partnership with Switzerland with important contributions to the payload and the ground segment from Austria, Belgium, France, Germany, Hungary, Italy, Portugal, Spain, Sweden, and the UK. The CHEOPS Consortium would like to gratefully acknowledge the support received by all the agencies, offices, universities, and industries involved. Their flexibility and willingness to explore new approaches were essential to the success of this mission. Funding for the TESS mission is provided by NASA Science Mission Directorate. We acknowledge the use of public TESS data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. This research has made use of the Exoplanet Follow-up Observation Program website, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. Part of this work was done using data taken by KESPRINT, an international consortium devoted to the characterization and research of exoplanets discovered with space-based missions (http://www.kesprint.science/). This work makes use of observations from the LCOGT network. Part of the LCOGT telescope time was granted by NOIRLab through the Mid-Scale Innovations Program (MSIP). MSIP is funded by NSF. This study is based on data collected under the NGTS project at the ESO La Silla Paranal Observatory. The NGTS facility is operated by the consortium institutes with support from the UK Science and Technology Facilities Council (STFC) projects ST/M001962/1 and ST/S002642/1. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This work makes use of observations from the ASTEP telescope. ASTEP benefited from the support of the French and Italian polar agencies IPEV and PNRA in the framework of the Concordia station program and from Idex UCAJEDI (ANR-15-IDEX-01). Some of the observations in the paper made use of the High-Resolution Imaging instrument Zorro. Zorro was funded by the NASA Exoplanet Exploration Program and built at the NASA Ames Research Center by Steve B. Howell, Nic Scott, Elliott P. Horch, and Emmett Quigley. Zorro was mounted on the Gemini-South telescope of the international Gemini Observatory, a program of NSF’s OIR Lab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation on behalf of the Gemini partnership: the National Science Foundation (USA), National Research Council Canada (Canada), Agencia Nacional de Investigación y Desarrollo (Chile), Ministerio de Ciencia, Tecnología e Innovación (Argentina), Ministério da Ciência, Tecnologia, Inovações e Comunicações (Brazil), and Korea Astronomy and Space Science Institute (Republic of Korea). TGW, ACC, and KH acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant ST/R003203/1. YA and MJH acknowledge the support of the Swiss National Fund under grant 200020_172746. DG and LMS gratefully acknowledge financial support from the CRT Foundation under grant no. 2018.2323 ‘Gaseous or rocky? Unveiling the nature of small worlds’. DG, MF, XB, SC, and JL acknowledge their roles as ESA-appointed CHEOPS science team members. CMP, MF, JK, and AJM gratefully acknowledge the support of the Swedish National Space Agency (SNSA; DNR 65/19, 174/18, 2020-00104, and Career grant 120/19C). ADe and DE acknowledge support from the European Research Council (ERC) under the European Union’s Horizon 2020 Framework Programme (project fOURaCES; grant agreement no. 724427). ADe, ALe, and HO acknowledge support from the Swiss National Centre for Competence in Research ‘PlanetS’ and the Swiss National Science Foundation (SNSF). SH gratefully acknowledges CNES funding through the grant 837319. SES have received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 Framework Programme (grant agreement no. 833925, project STAREX). SGS acknowledges support from FCT through FCT contract no. CEECIND/00826/2018 and POPH/FSE (EC). We acknowledge support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grants ESP2016-80435-C2-1-R, ESP2016-80435-C2-2-R, PGC2018-098153-B-C33, PGC2018-098153-B-C31, ESP2017-87676-C5-1-R, MDM-2017-0737 Unidad de Excelencia Maria de Maeztu-Centro de Astrobiología (INTA-CSIC), and the support of the Generalitat de Catalunya/CERCA programme. The MOC activities have been supported by the ESA contract no. 4000124370. SCCB and VA acknowledge support from FCT through FCT contracts no. IF/01312/2014/CP1215/CT0004 and IF/00650/2015/CP1273/CT0001, respectively. ABr was supported by the SNSA. This project was supported by the CNES. LD is an F.R.S.-FNRS Postdoctoral Researcher. The Belgian participation to CHEOPS has been supported by the Belgian Federal Science Policy Office (BELSPO) in the framework of the PRODEX Program, and by the University of Liège through an ARC grant for Concerted Research Actions financed by the Wallonia-Brussels Federation. This work was supported by FCT – Fundação para a Ciência e a Tecnologia – through national funds and by FEDER through COMPETE2020 – Programa Operacional Competitividade e Internacionalizacão by these grants: UID/FIS/04434/2019, UIDB/04434/2020, UIDP/04434/2020, PTDC/FIS-AST/32113/2017 & POCI-01-0145-FEDER-032113, PTDC/FIS-AST/28953/2017 & POCI-01-0145-FEDER-028953, PTDC/FIS-AST/28987/2017, and POCI-01-0145-FEDER-028987, ODSD is supported in the form of work contract (DL 57/2016/CP1364/CT0004) funded by national funds through FCT. B-OD acknowledges support from the Swiss National Science Foundation (PP00P2-190080). DD acknowledges support from the TESS Guest Investigator Program grant 80NSSC19K1727 and NASA Exoplanet Research Program grant 18-2XRP18_2-0136. MG is an F.R.S.-FNRS Senior Research Associate. KGI is the ESA CHEOPS Project Scientist and is responsible for the ESA CHEOPS Guest Observers Programme. She does not participate in, or contribute to, the definition of the Guaranteed Time Programme of the CHEOPS mission through which observations described in this paper have been taken, nor to any aspect of target selection for the programme. GL acknowledges support by CARIPARO Foundation, according to the agreement CARIPARO-Universitá degli Studi di Padova (Pratica no. 2018/0098). This work was granted access to the HPC resources of MesoPSL financed by the Region Ile de France and the project Equip@Meso (reference ANR-10-EQPX-29-01) of the programme Investissements d’Avenir supervised by the Agence Nationale pour la Recherche. ML acknowledges support from the Swiss National Science Foundation under grant no. PCEFP2_194576. PFLM acknowledges support from STFC research grant number ST/M001040/1. LDN thanks the Swiss National Science Foundation for support under Early Postdoc. Mobility grant P2GEP2_200044. This work was also partially supported by a grant from the Simons Foundation (PI: Queloz, grant number 327127). IR acknowledges support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grant PGC2018-098153-B-C33, as well as the support of the Generalitat de Catalunya/CERCA programme. This project has been supported by the Hungarian National Research, Development and Innovation Office (NKFIH) grant K-125015, the MTA-ELTE Lendület Milky Way Research Group, and the City of Szombathely under agreement no. 67.177-21/2016. This research received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 Framework Programme (grant agreement no. 803193/BEBOP), and from the Science and Technology Facilities Council (STFC; grant no. ST/S00193X/1). VVG is an F.R.S-FNRS Research Associate., With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.

Past occultation and phase-curve observations of the ultra-short period super-Earth 55 Cnc e obtained at visible and infrared wavelengths have been challenging to reconcile with a planetary reflection and emission model. In this study, we analyse a set of 41 occultations obtained over a two-year timespan with the CHEOPS satellite. We report the detection of 55 Cnc e's occultation with an average depth of 12 ± 3 ppm. We derive a corresponding 2Ïà  upper limit on the geometric albedo of Ag < 0.55 once decontaminated from the thermal emission measured by Spitzer at 4.5 μm. CHEOPSâà €à ™ s photometric performance enables, for the first time, the detection of individual occultations of this super-Earth in the visible and identifies short-timescale photometric corrugations likely induced by stellar granulation. We also find a clear 47.3-day sinusoidal pattern in the time-dependent occultation depths that we are unable to relate to stellar noise, nor instrumental systematics, but whose planetary origin could be tested with upcoming JWST occultation observations of this iconic super-Earth., Astronomy & Astrophysics, 669, ISSN:0004-6361, ISSN:1432-0746

The Next Generation Transit Survey (NGTS) is a photometric survey for transiting exoplanets, consisting of twelve identical 0.2-m telescopes. We report a measurement of the transit of HD106315c using a novel observing mode in which multiple NGTS telescopes observed the same target with the aim of increasing the signal-to-noise. Combining the data allows the robust detection of the transit, which has a depth less than 0.1 per cent, rivalling the performance of much larger telescopes. We demonstrate the capability of NGTS to contribute to the follow-up of K2 and TESS discoveries using this observing mode. In particular, NGTS is well-suited to the measurement of shallow transits of bright targets. This is particularly important to improve orbital ephemerides of relatively long-period planets, where only a small number of transits are observed from space., 11 pages, 9 figures, 3 tables. Resubmitted to Astronomische Nachrichten following review and revision

We report the discovery of a new ultra-short-period planet and summarize the properties of all such planets for which the mass and radius have been measured. The new planet, EPIC~228732031b, was discovered in {\it K2} Campaign 10. It has a radius of 1.81$^{+0.16}_{-0.12}~R_{\oplus}$ and orbits a G dwarf with a period of 8.9 hours. Radial velocities obtained with Magellan/PFS and TNG/HARPS-N show evidence for stellar activity along with orbital motion. We determined the planetary mass using two different methods: (1) the "floating chunk offset" method, based only on changes in velocity observed on the same night, and (2) a Gaussian process regression based on both the radial-velocity and photometric time series. The results are consistent and lead to a mass measurement of $6.5 \pm 1.6~M_{\oplus}$, and a mean density of $6.0^{+3.0}_{-2.7}$~g~cm$^{-3}$., Comment: 24 pages, 14 figures, accepted to AJ

We report on the discovery of three transiting planets around GJ~9827. The planets have radii of 1.75$_{-0.12}^{+0.11 }$, 1.36$_{- 0.09 }^{+ 0.09}$, and 2.10$_{- 0.15 }^{+ 0.15 }$~R$_{\oplus}$, and periods of 1.20896, 3.6480, and 6.2014 days, respectively. The detection was made in Campaign 12 observations as part of our K2 survey of nearby stars. GJ~9827 is a $V = 10.39$~mag K6V star at distance of 30.3 parsecs and the nearest star to be found hosting planets by Kepler and K2. The radial velocity follow-up, high resolution imaging, and detection of multiple transiting objects near commensurability drastically reduce the false positive probability. The orbital periods of GJ~9827~b, c and d planets are very close to the 1:3:5 mean motion resonance. Our preliminary analysis shows that GJ~9827 planets are excellent candidates for atmospheric observations. Besides, the planetary radii span both sides of the rocky and gaseous divide, hence the system will be an asset in expanding our understanding of the threshold., Comment: 9 pages, 4 figures. Submitted to AAS Journals

HD3167 is a bright (V=8.9 mag) K0V star observed by the NASA's K2 space mission during its Campaign 8. It has been recently found to host two small transiting planets, namely, HD3167b, an ultra short period (0.96 d) super-Earth, and HD3167c, a mini-Neptune on a relatively long-period orbit (29.85 d). Here we present an intensive radial velocity follow-up of HD3167 performed with the FIES@NOT, HARPS@ESO-3.6m, and HARPS-N@TNG spectrographs. We revise the system parameters and determine radii, masses, and densities of the two transiting planets by combining the K2 photometry with our spectroscopic data. With a mass of 5.69+/-0.44 MEarth, radius of 1.574+/-0.054 REarth, and mean density of 8.00(+1.0)(-0.98) g/cm^3, HD3167b joins the small group of ultra-short period planets known to have a rocky terrestrial composition. HD3167c has a mass of 8.33 (+1.79)(-1.85) MEarth and a radius of 2.740(+0.106)(-0.100) REarth, yielding a mean density of 2.21(+0.56)(-0.53) g/cm^3, indicative of a planet with a composition comprising a solid core surrounded by a thick atmospheric envelope. The rather large pressure scale height (about 350 km) and the brightness of the host star make HD3167c an ideal target for atmospheric characterization via transmission spectroscopy across a broad range of wavelengths. We found evidence of additional signals in the radial velocity measurements but the currently available data set does not allow us to draw any firm conclusion on the origin of the observed variation., Comment: 18 pages, 11 figures, 5 tables

We report the characterization and independant detection of K2-60b, as well as the detection and characterization of EPIC 216468514b, two transiting hot gaseous planets from the K2 space mission. We confirm the planetary nature of the two systems and determine their fundamental parameters combining the K2 time-series data with FIES@NOT and HARPS-N@TNG spectroscopic observations. K2-60b has a radius of 0.683 +/- 0.037 RJup and a mass of 0.426 +/- 0.037 MJup and orbits a G4V star with an orbital period of 3.00267 +/- 0.00006 days. EPIC 216468514b has a radius of 1.44 +/- 0.15RJup and a mass of 0.84 +/- 0.08 MJup and orbits an F9 IV star every 3.31392 +/- 0.00002 days. K2-60b is among the few planets at the edge of the so-called "desert" of short-period sub Jovian planets. EPIC 216468514b is a highly inflated Jovian planet orbiting an evolved star about to leave the main sequence., 10 pages, 10 figures