Search Publications
HIP 41378 observed by CHEOPS: Where is planet d?
Alonso, R.; Deleuil, M.; Erikson, A. +84 more
HIP 41378 d is a long-period planet that has only been observed to transit twice, three years apart, with K2. According to stability considerations and a partial detection of the Rossiter-McLaughlin effect, Pd = 278.36 d has been determined to be the most likely orbital period. We targeted HIP 41378 d with CHEOPS at the predicted transi…
Multiwavelength study of on-disk coronal-hole jets with IRIS and SDO observations
Koletti, M.; Gontikakis, C.; Patsourakos, S. +1 more
Context. Solar jets are an important field of study, as they may contribute to the mass and energy transfer from the lower to the upper atmosphere. Aims. We use the Interface Region Imaging Spectrograph (IRIS) and Solar Dynamic Observatory (SDO) observations to study two small-scale jets (jet 1 and jet 2) originating in the same on-disk coronal ho…
Large-scale stellar age-velocity spiral pattern in NGC 4030
Brinchmann, Jarle; Krajnović, Davor; Falcón-Barroso, Jesus +11 more
The processes driving the formation and evolution of late-type galaxies continue to be a debated subject in extragalactic astronomy. Investigating stellar kinematics, especially when combined with age estimates, provides crucial insights into the formation and subsequent development of galactic discs. Post-processing of exceptionally high-quality …
Anomalously low-mass core-He-burning star in NGC 6819 as a post-common-envelope phase product
Tailo, Marco; Miglio, Andrea; Montalbán, Josefina +5 more
Precise masses of red giant stars enable a robust inference of their ages, but there are cases where these age estimates are very precise but also very inaccurate. Examples are core-helium-burning (CHeB) stars that have lost more mass than predicted by standard single-star evolutionary models. Members of star clusters in the Kepler database repres…
Characterisation of TOI-406 as a showcase of the THIRSTEE program: A two-planet system straddling the M-dwarf density gap
Bouchy, F.; Pallé, E.; Zapatero Osorio, M. R. +31 more
Context. The exoplanet sub-Neptune population currently poses a conundrum, as to whether small-size planets are volatile-rich cores without an atmosphere, or rocky cores surrounded by a H-He envelope. To test the different hypotheses from an observational point of view, a large sample of small-size planets with precise mass and radius measurements…
Understanding the unusual life of the Cartwheel galaxy using stellar populations
Wolter, A.; Ditrani, F. R.; Longhetti, M. +1 more
Collisional ring galaxies (RiGs) are the result of the impact between two galaxies, with one of them passing close to the centre of the other, piercing its gaseous and stellar disc. In this framework, the impact generates a shock wave front that propagates within the disc of the target galaxy soon after the encounter, producing a characteristic ex…
TESS discovery of two super-Earths orbiting the M-dwarf stars TOI-6002 and TOI-5713 near the radius valley
Narita, N.; Palle, E.; Kaltenegger, L. +45 more
We present the validation of two TESS super-Earth candidates transiting the mid-M dwarfs TOI-6002 and TOI-5713 every 10.90 and 10.44 days, respectively. The first star (TOI-6002) is located 32.038 ± 0.019 pc away, with a radius of 0.2409‑0.0065+0.0066 R⊙, a mass of 0.2105‑0.0048+0.0049 M⊙…
Electron moments derived from the Mercury Electron Analyzer during the cruise phase of BepiColombo
André, N.; Fedorov, A.; Sauvaud, J. -A. +20 more
Aims: We derive electron density and temperature from observations obtained by the Mercury Electron Analyzer on board Mio during the cruise phase of BepiColombo while the spacecraft is in a stacked configuration.
Methods: In order to remove the secondary electron emission contribution, we first fit the core electron population of the sol…
Very long baseline interferometry detection of nearby (<100 pc) young stars. Pilot observations
Loinard, Laurent; Launhardt, Ralf; Dzib, Sergio A. +1 more
To increase the number of sources with very long baseline interferometry (VLBI) astrometry available for comparison with the Gaia results, we have observed 31 young stars with recently reported radio emission. These stars are all in the Gaia DR3 catalog and were suggested, on the basis of conventional interferometry observations, to be nonthermal …
Two black widow pulsars in the optical and X-rays
Zharikov, S. V.; Karpova, A. V.; Shibanov, Yu. A. +5 more
Context. Two millisecond pulsars, PSR J1513‑2550 and PSR J2017‑1614, with spin periods of about 2.1 and 2.3 ms were recently discovered in the radio and γ-rays and classified as black widow pulsars in tight binary stellar systems with orbital periods of about 4.3 and 2.3 h. Aims. Our goals are to reveal the fundamental parameters of both systems a…