Search Publications
KMT-2022-BLG-0440Lb: A new q < 10-4 microlensing planet with the central-resonant caustic degeneracy broken
Maoz, Dan; Han, Cheongho; Lee, Chung-Uk +58 more
We present the observations and analysis of a high-magnification microlensing planetary event, KMT-2022-BLG-0440, for which the weak and short-lived planetary signal was covered by both the KMTNet survey and follow-up observations. The binary-lens models with a central caustic provide the best fits, with a planet/host mass ratio, q = 0.75-1.00 × 1…
AIROPA IV: Validating point spread function reconstruction on various science cases
Lu, Jessica R.; Fitzgerald, Michael P.; Do, Tuan +7 more
We present an analysis of six independent on-sky datasets taken with the Keck-II/NIRC2 instrument. Using the off-axis point spread function (PSF) reconstruction software AIROPA, we extract stellar astrometry, photometry, and other fitting metrics to characterize the performance of this package. We test the effectiveness of AIROPA to reconstruct th…
Imaging and spectroscopic observations of extreme-ultraviolet brightenings using EUI and SPICE on board Solar Orbiter
Peter, H.; Chitta, L. P.; Solanki, S. K. +16 more
Context. The smallest extreme-ultraviolet (EUV) brightening events that were detected so far, called campfires, have recently been uncovered by the High Resolution EUV telescope (HRIEUV), which is part of the Extreme Ultraviolet Imager (EUI) on board Solar Orbiter. HRIEUV has a broad bandpass centered at 17.4 nm that is domin…
Self-consistent nanoflare heating in model active regions: MHD avalanches
Hood, A. W.; Threlfall, J.; Reid, J.
Straightened cylindrical models of coronal loops have been standard for decades, and shown to support nanoflare-like heating, but the influence of geometric curvature in models upon the heating produced has not been discussed in depth. Heating, its spatiotemporal distributions, and the associated mechanisms responsible are discussed, and compared …
A study of the rapid rotator ζ Aql: differential surface rotation?
Bailey, Jeremy; Cotton, Daniel V.; Howarth, Ian D. +1 more
We report new, extremely precise photopolarimetry of the rapidly-rotating A0 main-sequence star ζ Aql, covering the wavelength range ~400-900 nm, which reveals a rotationally-induced signal. We model the polarimetry, together with the flux distribution and line profiles, in the framework of Roche geometry with ω-model gravity darkening, to establi…
The GAPS programme at TNG. XLIV. Projected rotational velocities of 273 exoplanet-host stars observed with HARPS-N
Scandariato, G.; Poretti, E.; Rainer, M. +25 more
Context. The leading spectrographs used for exoplanets' search and characterization offer online data reduction softwares (DRS) that yield, as an ancillary result, the full-width at half-maximum (FWHM) of the cross-correlation function (CCF) that is used to estimate the radial velocity of the host star. The FWHM also contains information on the st…
The first massive compact companion in a wide orbit around a hot subdwarf star
Geier, S.; Heber, U.; Marsh, T. R. +5 more
We report the discovery of the first hot subdwarf B (sdB) star with a massive compact companion in a wide (P = 892.5 ± 60.2 d) binary system. It was discovered based on an astrometric binary solution provided by the Gaia mission Data Release 3. We performed detailed analyses of the spectral energy distribution (SED) as well as spectroscopic follow…
Discovery of inverse-Compton X-ray emission and estimate of the volume-averaged magnetic field in a galaxy group
Simionescu, A.; Mernier, F.; Shimwell, T. W. +6 more
Observed in a significant fraction of clusters and groups of galaxies, diffuse radio synchrotron emission reveals the presence of relativistic electrons and magnetic fields permeating large scale systems of galaxies. Although, these non-thermal electrons are expected to upscatter cosmic microwave background photons up to hard X-ray energies, such …
The role of magnetic fields in the formation of the filamentary infrared dark cloud G11.11-0.12
Chen, Zhiwei; Su, Yang; Zhang, Shaobo +4 more
We report on the near-infrared polarimetric observations of G11.11-0.12 (hereafter G11) obtained with SIRPOL on the 1.4 m IRSF telescope. The starlight polarisation of the background stars reveals the on-sky component of magnetic fields in G11, and these are consistent with the field orientation observed from polarised dust emission at $850\, \mu$…
VaTEST. II. Statistical Validation of 11 TESS-detected Exoplanets Orbiting K-type Stars
Triaud, Amaury H. M. J.; Bieryla, Allyson; Littlefield, Colin +48 more
NASA's Transiting Exoplanet Survey Satellite (TESS) is an all-sky survey mission designed to find transiting exoplanets orbiting nearby bright stars. It has identified more than 329 transiting exoplanets, and almost 6000 candidates remain unvalidated. In this manuscript, we discuss the findings from the ongoing Validation of Transiting Exoplanets …