Search Publications
Commissioning and improvements of the instrumentation and launch of the scientific exploitation of OARPAF, the Regional Astronomical Observatory of the Antola Park
Righi, Chiara; Landoni, Marco; Ricci, Davide +18 more
The OARPAF telescope is an 80-cm-diameter optical telescope installed in the Antola Mount Regional Reserve, in Northern Italy. We present the results of the characterization of the site, as well as developments and interventions that have been implemented, with the goal of exploiting the facility for scientific and educational purposes. During the…
Pulkovo observations of apparent close approaches between near-earth asteroids and the Gaia stars in 2019-2020
Bikulova, D. A.
The astrometric observations of the apparent close approaches between near-Earth asteroids and the Gaia stars provide high quality data for studies on the dynamics of these objects. We present the technique of data analysis that allows us to decrease the distortion-dependent positional errors and observational results of eight of such events perfo…
Evidence for fluvial and glacial activities within impact craters that excavated into a Noachian volcanic dome on Mars
Harish; Vijayan, S.; Mangold, N.
Impact craters on Mars preserve diverse records of volcanic, fluvial, and glacial activities. Enigmatically, the preservation of these major activities or records altogether within impact craters is rare. We report one such new observation of impact craters that formed on a volcanic dome studied using data from the Mars Reconnaissance Orbiter's (M…
ALMA View of the ρ Ophiuchi A PDR with a 360 au Beam: The [C I] Emission Originates from the Plane-parallel PDR and Extended Gas
Nakamura, Fumitaka; Shimajiri, Yoshito; Yamagishi, Mitsuyoshi +5 more
We present the results of data analysis of the [C I] (3P1-3P0) emission from the ρ Ophiuchi A photon-dominated region (PDR) obtained in the ALMA ACA standalone mode with a spatial resolution of 2.6 arcsec (360 au). The [C I] emission shows filamentary structures with a width of ∼1000 au, which are adjace…
Neptune's HCl upper limit from Herschel/HIFI
Irwin, P. G. J.; Teanby, N. A.; Gould, B.
Here we search for hydrogen chloride (HCl) in Neptune's stratosphere using observations of the 1876.22 GHz J=3-2 transition from the Heterodyne Instrument for the Far-Infrared (HIFI) on Herschel. Observations comprise a 7.2 hr disc-averaged integration, originally designed to investigate stratospheric methane. Significant HCl emission was not dete…
Do MURaM and STAGGER Simulations of Solar Faculae Match Observational Signatures from Magnetic Structures?
Cubas Armas, Melania; Fabbian, Damian
We compare results of simulations of solar facular-like conditions performed using the numerical codes MURaM and STAGGER. Both simulation sets have a similar setup, including the initial condition of ≈200 G vertical magnetic flux. After interpolating the output physical quantities to constant optical depth, we compare them and test them against in…
Extreme adaptive optics astrometry of R136. Searching for high proper motion stars
Vakili, F.; Boccaletti, A.; Langlois, M. +9 more
We compared high-contrast near-infrared images of the core of R136 taken by VLT/SPHERE, in two epochs separated by 3.06 years. For the first time we monitored the dynamics of the detected sources in the core of R136 from a ground-based telescope with adaptive optics. The aim of these observations was to search for High prOper Motion cAndidates (HO…
The Micro-Macro Coupling of Mass-Loading in Symmetric Magnetic Reconnection With Cold Ions
Hesse, Michael; Spinnangr, Susanne F.; Tenfjord, Paul +4 more
We investigate how magnetic reconnection is influenced by an inflow of a dense cold ion population. We compare two 2.5D Particle-In-Cell simulations, one containing the cold population and one without. We find that the cold population influences the reconnection process on both global and kinetic scales, and that the dominant contribution can be e…
Functional Principal Component Analysis of Radio-Optical Reference Frame Tie
Makarov, Valeri V.
The Gaia optical reference frame is intrinsically undefined with respect to global orientation and spin, so it needs to be anchored in the radio-based International Celestial Reference Frame (ICRF) to provide a referenced and quasi-inertial celestial coordinate system. The link between the two fundamental frames is realized through two samples of …
Search for LBVs in the Local Volume galaxies: study of four stars in NGC 4449
Vinokurov, A.; Solovyeva, Y.; Atapin, K. +8 more
We continue to search for LBV stars in galaxies outside the Local Group. In this work, we have investigated four luminous stars in NGC 4449. Multiple spectral observations carried out for J122810.94+440540.6, J122811.70+440550.9, and J122809.72+440514.8 revealed the emission features in their spectra that are characteristic of LBVs. Photometry sho…