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Although more than a thousand transiting extrasolar planets have been discovered, only very few of them orbit stars that are more massive than the Sun. The discovery of such planets is interesting, because they have formed in disks that are more massive but had a shorter life time than those of solar-like stars. Studies of planets more massive than the Sun thus tell us how the properties of the proto-planetary disks effect the formation of planets. Another aspect that makes these planets interesting is that they have kept their original orbital inclinations. By studying them we can thus find out whether the orbital axes planets are initially aligned to the stars rotational axes, or not. Here we report on the discovery of a planet of a 1.4 solar-mass star with a period of 5.6 days in a polar orbit made by CoRoT. This new planet thus is one of the few known close-in planets orbiting a star that is substantially more massive than the Sun.

The Ultraviolet Transient Astronomy Satellite (ULTRASAT) is scheduled to be launched to geostationary orbit in 2027. It will carry a telescope with an unprecedentedly large field of view (204 deg2) and near-ultraviolet (NUV; 230–290 nm) sensitivity (22.5 mag, 5σ, at 900 s). ULTRASAT will conduct the first wide-field survey of transient and variable NUV sources and will revolutionize our ability to study the hot transient Universe. It will explore a new parameter space in energy and timescale (months-long light curves with minutes cadence), with an extragalactic volume accessible for the discovery of transient sources that is >300 times larger than that of the Galaxy Evolution Explorer (GALEX) and comparable to that of the Vera Rubin Observatory’s Legacy Survey of Space and Time. ULTRASAT data will be transmitted to the ground in real time, and transient alerts will be distributed to the community in <15 minutes, enabling vigorous ground-based follow up of ULTRASAT sources. ULTRASAT will also provide an all-sky NUV image to >23.5 AB mag, over 10 times deeper than the GALEX map. Two key science goals of ULTRASAT are the study of mergers of binaries involving neutron stars, and supernovae. With a large fraction (>50%) of the sky instantaneously accessible, fast (minutes) slewing capability, and a field of view that covers the error ellipses expected from gravitational-wave (GW) detectors beyond 2026, ULTRASAT will rapidly detect the electromagnetic emission following binary neutron star/neutron star–black hole mergers identified by GW detectors, and will provide continuous NUV light curves of the events. ULTRASAT will provide early (hour) detection and continuous high-cadence (minutes) NUV light curves for hundreds of core-collapse supernovae, including for rarer supernova progenitor types.

The Kepler Object of Interest Network (KOINet) is a multi-site network of telescopes around the globe organised to follow up transiting planet candidate KOIs with large transit timing variations (TTVs). Its main goal is to complete their TTV curves, as the Kepler telescope no longer observes the original Kepler field. Combining Kepler and new ground-based transit data we improve the modelling of these systems. To this end, we have developed a photodynamical model, and we demonstrate its performance using the Kepler-9 system as an example. Our comprehensive analysis combines the numerical integration of the system's dynamics over the time span of the observations along with the transit light curve model. This model is coupled with a Markov chain Monte Carlo algorithm, allowing the exploration of the model parameter space. Applied to the Kepler-9 long cadence data, short cadence data and 13 new transit observations collected by KOINet between the years 2014 to 2017, our modelling provides well constrained predictions for the next transits and the system's parameters. We have determined the densities of the planets Kepler-9b and 9c to the very precise values of rho_b = 0.439 +/-0.023 g/cm3 and rho_c = 0.322 +/- 0.017 g/cm3. Our analysis reveals that Kepler-9c will stop transiting in about 30 years. This results from strong dynamical interactions between Kepler-9b and 9c, near 2:1 resonance, that leads to a periodic change in inclination. Over the next 30 years the inclination of Kepler-9c (-9b) will decrease (increase) slowly. This should be measurable by a substantial decrease (increase) in the transit duration, in as soon as a few years' time. Observations that contradict this prediction might indicate the presence of additional objects. If this prediction proves true, this behaviour opens up a unique chance to scan the different latitudes of a star.

Radial velocity (RV) jitter represents an intrinsic limitation on the precision of Doppler searches for exoplanets that can originate from both instrumental and astrophysical sources. We aim to determine the RV jitter floor in M dwarfs and investigate the stellar properties that lead to RV jitter induced by stellar activity. We determined the RV jitter in 239 M dwarfs from the CARMENES survey that are predominantly of mid to late spectral type and solar metallicity. We also investigated the correlation between stellar rotation and magnetic fields with RV jitter. The median jitter in the CARMENES sample is 3.1 m/s, and it is 2.3 m/s for stars with an upper limit of 2 km/s on their projected rotation velocities. We provide a relation between the stellar equatorial rotation velocity and RV jitter in M dwarfs based on a subsample of 129 well-characterized CARMENES stars. RV jitter induced by stellar rotation dominates for stars with equatorial rotation velocities greater than 1 km/s. A jitter floor of 2 m/s dominates in stars with equatorial rotation velocities below 1 km/s. This jitter floor likely contains contributions from stellar jitter, instrumental jitter, and undetected companions. We study the impact of the average magnetic field and the distributions of magnetic filling factors on the RV jitter. We find a series of stars with excess RV jitter and distinctive distributions of magnetic filling factors. These stars are characterized by a dominant magnetic field component between 2-4 kG. An RV jitter floor can be distinguished from RV jitter induced by activity and rotation based on the stellar equatorial rotation velocity. RV jitter induced by activity and rotation primarily depends on the equatorial rotation velocity. This RV jitter is also related to the distribution of magnetic filling factors, and this emphasizes the role of the magnetic field in the generation of RV jitter.

Aims. We use the recently published database (Trifonov et al. 2020) of radial velocities (RVs) that were derived from fifteen years of HARPS/ESO observations to search for planet candidates. Methods. For targets with sufficient RV data, we apply an automated algorithm to identify significant periodic signals and fit a Keplerian model for orbital estimates. We also search the auxiliary data of stellar-activity indices and compare our findings with existing literature, to detect periodic RV signals that have no counterpart in the activity timeseries. The most convincing signals are then manually inspected to designate additional false planet detection, focusing the search on long-period (P > 1 000 d) massive candidates around FGK dwarf stars. Results. We identify two Jupiter analogs, in orbit around the slightly evolved F8V star HD 103891 and the Solar-like star HD 105779. We use nested sampling to derive their orbital parameters, and find their orbital periods to be 1919 +/- 16 d and 2412 +/- 54 d, while their minimum masses are 1.44 +/- 0.02 M Jup and 0.64 +/- 0.06 M Jup , respectively. While the orbit of HD 103891 b is slightly eccentric (e = 0.31 +/- 0.03), that of HD 105779 b is likely circular (e < 0.16). Conclusions. With minimum astrometric signatures of 59 and 42 \\(\\)as, HD 103891 b and HD 105779 b join the growing sample of planets whose exact masses may soon be derived with Gaia astrometry. This finding also highlights the importance of long-term RV surveys to study planetary occurrence beyond the snow line of Solar-like stars.

Magnetic activity is currently the primary limiting factor in radial velocity (RV) exoplanet searches. Even inactive stars, such as the Sun, exhibit RV jitter of the order of a few ms\\(^-1\\) due to active regions on their surfaces. Time series of chromospheric activity indicators, such as the Ca II H&K lines, can be utilized to reduce the impact of such activity phenomena on exoplanet search programmes. In addition, the identification and correction of instrumental effects can improve the precision of RV exoplanet surveys. We aim to update the HARPS-RVBank RV database and include an additional \\(3.5\\) years of time series and Ca II H&K lines (\\(R_HK^\\)) chromospheric activity indicators. This additional data will aid in the analysis of the impact of stellar magnetic activity on the RV time series obtained with the HARPS instrument. Our updated database aims to provide a valuable resource for the exoplanet community in understanding and mitigating the effects of such stellar magnetic activity on RV measurements. The new HARPS-RVBank database includes all stellar spectra obtained with the HARPS instrument prior to January 2022. The RVs corrected for small but significant nightly zero-point variations were calculated using an established method. The \\(R_HK^\\) estimates were determined from both individual spectra and co-added template spectra with the use of model atmospheres. The new version of the HARPS RV database has a total of 252615 RVs of 5239 stars. Of these, 195387 have \\(R_HK^\\) values, which corresponds to 77\\% of all publicly available HARPS spectra. Currently, this is the largest public database of high-precision (down to 1ms\\(^-1\\)) RVs, and the largest compilation of \\(R_HK^\\) measurements.

We report the confirmation and mass determination of a mini-Neptune transiting the M3.5 V star TOI-4438 (G 182-34) every 7.44 days. A transit signal was detected with NASA's TESS space mission in the sectors 40, 52, and 53. In order to validate the planet TOI-4438 b and to determine the system properties, we combined TESS data with high-precision radial velocity measurements from the CARMENES spectrograph, spanning almost one year, and ground-based transit photometry. We found that TOI-4438 b has a radius of Rb = 2.52 +/- 0.13 R_Earth (5% precision), which together with a mass of Mb=5.4 +/- 1.1 M_Earth (20% precision), results in a bulk density of rho = 1.85+0.51-0.44 g cm-3 (28% precision), aligning the discovery with a volatile-rich planet. Our interior structure retrieval with a pure water envelope yields a minimum water mass fraction of 46% (1-sigma). TOI-4438 b is a volatile-rich mini-Neptune with likely H/He mixed with molecules, such as water, CO_2, and CH_4. The primary star has a J-band magnitude of 9.7, and the planet has a high transmission spectroscopy metric (TSM) of 136 +/- 13. Taking into account the relatively warm equilibrium temperature of T_eq = 435 +/- 15 K, and the low activity level of its host star, TOI-4438 b is one of the most promising mini-Neptunes around an M dwarf for transmission spectroscopy studies.

Light from celestial objects interacts with the molecules of the Earth's atmosphere, resulting in the production of telluric absorption lines in ground-based spectral data. Correcting for these lines, which strongly affect red and infrared wavelengths, is often needed in a wide variety of scientific applications. Here, we present the template division telluric modeling (TDTM) technique, a method for accurately removing telluric absorption lines in stars that exhibit numerous intrinsic features. Based on the Earth's barycentric motion throughout the year, our approach is suited for disentangling telluric and stellar spectral components. By fitting a synthetic transmission model, telluric-free spectra are derived. We demonstrate the performance of the TDTM technique in correcting telluric contamination using a high-resolution optical spectral time series of the feature-rich M3.0 dwarf star Wolf 294 that was obtained with the CARMENES spectrograph. We apply the TDTM approach to the CARMENES survey sample, which consists of 382 targets encompassing 22357 optical and 20314 near-infrared spectra, to correct for telluric absorption. The corrected spectra are coadded to construct template spectra for each of our targets. This library of telluric-free, high signal-to-noise ratio, high-resolution (R>80000) templates comprises the most comprehensive collection of spectral M-dwarf data available to date, both in terms of quantity and quality, and is available at the project website (http://carmenes.cab.inta-csic.es).

Theories of planet formation give contradicting results of how frequent close-in giant planets of intermediate mass stars (IMSs; \\( 1.3 M_ 3.2\\,M_ \\)) are. Some theories predict a high rate of IMSs with close-in gas giants, while others predict a very low rate. Thus, determining the frequency of close-in giant planets of IMSs is an important test for theories of planet formation. We use the CoRoT survey to determine the absolute frequency of IMSs that harbour at least one close-in giant planet and compare it to that of solar-like stars. The CoRoT transit survey is ideal for this purpose, because of its completeness for gas-giant planets with orbital periods of less than 10 days and its large sample of main-sequence IMSs. We present a high precision radial velocity follow-up programme and conclude on 17 promising transit candidates of IMSs, observed with CoRoT. We report the detection of CoRoT-34b, a brown dwarf close to the hydrogen burning limit, orbiting a 1.1 Gyr A-type main-sequence star. We also confirm two inflated giant planets, CoRoT-35b, part of a possible planetary system around a metal-poor star, and CoRoT-36b on a misaligned orbit. We find that \\(0.12 0.10\\,\\%\\) of IMSs between \\(1.3 M_ 1.6 M_ \\) observed by CoRoT do harbour at least one close-in giant planet. This is significantly lower than the frequency (\\(0.70 0.16\\,\\%\\)) for solar-mass stars, as well as the frequency of IMSs harbouring long-period planets (\\( 8\\,\\%\\)).

We report the discovery of HN Lib b, a sub-Neptunian mass planet orbiting the nearby (\\(d \\) = 6.25 pc) M4.0 V star HN Lib detected by our CARMENES radial-velocity (RV) survey. We determined a planetary minimum mass of \\(M_b i = \\) 5.46 \\(\\) 0.75 \\(M_\\) and an orbital period of \\(P_b = \\) 36.116 \\(\\) 0.029 d, using \\(\\)5 yr of CARMENES data, as well as archival RVs from HARPS and HIRES spanning more than 13 years. The flux received by the planet equals half the instellation on Earth, which places it in the middle of the conservative habitable zone (HZ) of its host star. The RV data show evidence for another planet candidate with \\(M_[c] i = \\) 9.7 \\(\\) 1.9 \\(M_\\) and \\(P_[c] = \\) 113.46 \\(\\) 0.20 d. The long-term stability of the signal and the fact that the best model for our data is a two-planet model with an independent activity component stand as strong arguments for establishing a planetary origin. However, we cannot rule out stellar activity due to its proximity to the rotation period of HN Lib, which we measured using CARMENES activity indicators and photometric data from a ground-based multi-site campaign as well as archival data. The discovery adds HN Lib b to the shortlist of super-Earth planets in the habitable zone of M dwarfs, but HN Lib [c] probably cannot be inhabited because, if confirmed, it would most likely be an icy giant.