F. J. Aceituno
A5050149627- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- SAS software applications and methods
- Astrophysics and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Planetary Science and Exploration
- Astrophysics and Star Formation Studies
- Particle Accelerators and Free-Electron Lasers
- Radio Astronomy Observations and Technology
- Space Satellite Systems and Control
- Astrophysical Phenomena and Observations
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Adaptive optics and wavefront sensing
- Space Exploration and Technology
- Gyrotron and Vacuum Electronics Research
- Particle physics theoretical and experimental studies
- Particle accelerators and beam dynamics
- Pulsars and Gravitational Waves Research
- Isotope Analysis in Ecology
- Geomagnetism and Paleomagnetism Studies
- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
Instituto de Astrofísica de Andalucía
2014-2024
Consejo Superior de Investigaciones Científicas
2007-2023
Secretaría de Energía
2016
Secretaria do Meio Ambiente
2016
Abstract The physical and orbital parameters of trans-Neptunian objects provide valuable information about the solar system’s formation evolution. In particular, characterization binaries provides insights into mechanisms that may be playing a role at such large distances from Sun. Studies show two distinct populations, (38628) Huya occupies an intermediate position between unequal-sized those with components roughly equal sizes. this work, we predicted observed three stellar occultation...
Context. Teegarden's Star is the brightest and one of nearest ultra-cool dwarfs in solar neighbourhood. For its late spectral type (M7.0V), star shows relatively little activity a prime target for near-infrared radial velocity surveys such as CARMENES. Aims. As part CARMENES search exoplanets around M dwarfs, we obtained more than 200 radial-velocity measurements analysed them planetary signals. Methods. We find periodic variability velocities Star. also studied photometric to rule out...
Abstract The lower-energy peak of the spectral energy distribution blazars has commonly been ascribed to synchrotron radiation from relativistic particles in jets. Despite consensus regarding jet emission processes, particle acceleration mechanism is still debated. Here, we present first X-ray polarization observations PG 1553+113, a high-synchrotron-peak blazar observed by Imaging Polarimetry Explorer (IXPE). We detect an degree (10 ± 2)% along electric-vector position angle ψ X = 86° 8°....
Abstract We report the first >99% confidence detection of X-ray polarization in BL Lacertae. During a recent X-ray/ γ -ray outburst, 287 ks observation (2022 November 27–30) was taken using Imaging Polarimetry Explorer (IXPE), together with contemporaneous multiwavelength observations from Neil Gehrels Swift observatory and XMM-Newton soft X-rays (0.3–10 keV), NuSTAR hard (3–70 optical Calar Alto Perkins Telescope observatories. Our data suggest that IXPE energy band is at crossover...
Abstract Observations of linear polarization in the 2–8 keV energy range with Imaging X-ray Polarimetry Explorer (IXPE) explore magnetic field geometry and dynamics regions generating nonthermal radiation relativistic jets blazars. These jets, particularly blazars whose spectral distribution peaks at energies, emit X-rays via synchrotron from high-energy particles within jet. IXPE observations X-ray-selected BL Lac–type blazar 1ES 1959+650 on 2022 May 3–4 showed a significant degree Π x =...
We present the discovery and characterisation of two transiting planets observed by Transiting Exoplanet Survey Satellite (TESS) orbiting nearby (d ~ 22 pc), bright (J 9 mag) M3.5 dwarf LTT 3780 (TOI-732). confirm both their association with via ground-based photometry determine masses using precise radial velocities measured CARMENES spectrograph. Precise stellar parameters determined from high resolution spectra that is a mid-M an effective temperature T_eff = 3360 +\- 51 K, surface...
Abstract We present polarization measurements in the 2–8 keV band from blazar 1ES 0229+200, first extreme high synchrotron peaked source to be observed by Imaging X-ray Polarimetry Explorer (IXPE). Combining two exposures separated about weeks, we find degree of Π X = 17.9% ± 2.8% at an electric-vector position angle ψ 25.°0 4.°6 using a spectro-polarimetric fit joint IXPE and XMM-Newton observations. There is no evidence for or varying significantly with energy time on both short timescales...
Aims. We aim to probe the magnetic field geometry and particle acceleration mechanism in relativistic jets of supermassive black holes. Methods. conducted a polarimetry campaign from radio X-ray wavelengths high-synchrotron-peak (HSP) blazar Mrk 421, including Imaging Polarimetry Explorer (IXPE) measurements 2022 December 6–8. During IXPE observation, we also monitored 421 using Swift -XRT obtained single observation with XMM-Newton improve spectral analysis. The time-averaged polarization...
Aims. Knowledge of rotation periods ( P rot ) is important for understanding the magnetic activity and angular momentum evolution late-type stars, as well evaluating radial velocity signals potential exoplanets identifying false positives. We measured photometric spectroscopic a large sample nearby bright M dwarfs with spectral types from M0 to M9, part our continual effort fully characterize Guaranteed Time Observation programme stars CARMENES survey. Methods. analyse light curves chiefly...
We report the X-ray polarization properties of high-synchrotron-peaked (HSP) blazar PKS 2155−304 based on observations with Imaging Polarimetry Explorer (IXPE). observed source between Oct 27 and Nov 7, 2023. also conducted an extensive contemporaneous multiwavelength (MW) campaign. find that during first half ( T 1 ) IXPE pointing, exhibited highest degree detected for HSP thus far, (30.7 ± 2.0)%; this dropped to (15.3 2.1)% second 2 ). The angle remained stable pointing at 129.4° ±1.8°...
The X-ray polarization observations, made possible with the Imaging Polarimetry Explorer (IXPE), offer new ways of probing high-energy emission processes in astrophysical jets from blazars. Here, we report first observation blazar S4 0954+65 a high optical and state. During our multi-wavelength (MWL) campaign source, detected an flare whose peak coincided flare. This optical-X-ray most likely took place feature moving along parsec-scale jet, imaged at 43 GHz by Very Long Baseline Array...
We present results of 6 years observations, reduced and analyzed with the same tools in a systematic way. report completely new data for 15 objects, 5 objects we analysis previously published plus additional 9 already published. Lightcurves, possible rotation periods photometric amplitudes are reported all them. The variability is smaller than thought: mean amplitude our sample 0.1mag only around 15% has larger 0.15mag. thought seems to be bias previous observations. find very weak trend...
Discovery of the first planetary system by direct imaging around HR8799 has made age determination host star a very important task. This is key to derive accurate masses planets and study dynamical stability system. The this been estimated using different procedures. In work we show that some these procedures have problems large uncertainties, real still unknown, needing more observational constraints. Therefore, developed comprehensive modeling HR8799, taking advantage its gamma...
There have been previous hints that the transiting planet WASP-3 b is accompanied by a second in nearby orbit, based on small deviations from strict periodicity of observed transits. Here we present 17 precise radial velocity measurements and 32 transit light curves were acquired between 2009 2011. These data used to refine parameters host star planet. This has resulted reduced uncertainties for radii masses The radial-velocity times show no evidence an additional system. Therefore,...
We thank the referee for valuable comments which improved paper. also Dr. Laetitia Delrez and Pedro Sada sharing WASP-103 HAT-P-23 light curves with us. GM MS acknowledge financial support from National Science Centre, Poland through grant no. 2016/23/B/ST9/00579. MF acknowledges grants AYA2014-54348-C3-1-R AYA2016-79425-C3-3-P of Spanish Ministry Economy Competitiveness (MINECO), co-funded EU FEDER funds. DD projects DN 08-1/2016, 08-20/2016 Foundation Bulgarian education science as well by...
Statistical analyses from exoplanet surveys around low-mass stars indicate that super-Earth and Neptune-mass planets are more frequent than gas giants such stars, in agreement with core accretion theory of planet formation. Using precise radial velocities derived visual near-infrared spectra, we report the discovery a giant minimum mass 0.46 Jupiter masses an eccentric 204-day orbit very star GJ 3512. Dynamical models show high eccentricity is most likely explained planet-planet...
Hot Jupiters have been perceived as loners devoid of planetary companions in close orbital proximity. However, recent discoveries based on space-borne precise photometry revealed that at least some fraction giant planets coexists with low-mass compact architectures. We report detecting a 1.446-day transit-like signal the photometric time series acquired Transiting Exoplanet Survey Satellite (TESS) for WASP-84 system, which is known to contain hot Jupiter circular 8.5-day orbit. The planet...
The physical and orbital parameters of Trans-Neptunian Objects (TNOs) provide valuable information about the Solar System's formation evolution. In particular, characterization binaries provides insights into mechanisms that may be playing a role at such large distances from Sun. Studies show two distinct populations, (38628) Huya occupies an intermediate position between unequal-size those with components roughly equal sizes. this work, we predicted observed three stellar occultation events...
We present the results of a three-continent multisite photometric campaign carried out on Algol-type eclipsing binary system Y Cam, in which primary component is multiperiodic δ Sct-type pulsator. The observations consist 86 nights and more than 450 h useful data collected mainly during Northern winter 2002–2003. This means that this most extensive time series for such kind systems obtained so far. These were mostly Johnson V filter, but they also include, first time, nearly complete light...
As part of our ongoing effort to investigate transit timing variations (TTVs) known exoplanets, we monitored transits the four exoplanets HAT-P-18b, HAT-P-19b, HAT-P-27b/WASP-40b and WASP-21b. All them are suspected show TTVs due properties their host systems based on respective discovery papers. During past three years 46 observations were carried out, mostly using telescopes Young Exoplanet Transit Initiative. The analyses used refine systems' orbital parameters. In all cases found no...
Aims.We present multiwavelength (X-ray/optical/near-infrared/millimetre) observations of GRB 051022 between 2.5 h and ~1.15 yr after the event. It is most intense gamma-ray burst (~10-4 erg cm-2) detected by HETE-2, with exception nearby 030329.