Search Publications
Chrono-morphologic surface- a parameter to quantify craters' heterogeneity and its applicability on Mars
Căpitan, Radu Dan
On any solid planetary surface, crater populations in any given region show variations in their geomorphology related to their initial formation conditions and to their post-formation modifications. This ubiqutous and random distribution of craters in time and space defines a universal cratering characteristic- the craters heterogeneity, that is p…
Speckle Interferometry at the U.S. Naval Observatory. XXIV
Matson, Rachel A.; Williams, Stephen J.; Mason, Brian D. +5 more
The results of 3611 intensified CCD observations of double stars, made with the 26 inch refractor of the U.S. Naval Observatory, are presented. Each observation of a system represents a combination of over 2000 short-exposure images. These observations are averaged into 1857 mean relative positions and range in separation from 0"341 to 128"644, wi…
Spatial Distribution of Ultraviolet Emission from Cometary Activity at 67P/Churyumov-Gerasimenko
Parker, Joel Wm.; Bertaux, Jean-Loup; Weaver, Harold A. +16 more
The Alice ultraviolet spectrograph on board the Rosetta orbiter provided the first near-nucleus ultraviolet observations of a cometary coma from arrival at comet 67P/Churyumov-Gerasimenko in 2014 August through 2016 September. The characterization of atomic and molecular emissions in the coma revealed the unexpected contribution of dissociative el…
Improving light curve parameters of exoplanets based on TESS data
Parviainen, H.; Maliuk, A.; Vítková, M. +1 more
We revise parameters of four transiting hot Jupiter planets discovered by ground-based surveys. We use follow-up observations carried by TESS mission together with PyTransit software. Space telescopes like TESS provide better coverage and photometry precision than ground-based telescopes. PyTransit is fast and user-friendly exoplanet transit light…
Analysis of modern astrometric catalogues in the Gaia era
Akhmetov, V. S.; Fedorov, P. N.; Tsvetkova, V. S. +1 more
We investigate the systems of proper motions of stars in the ground-based catalogues HSOY, UCAC5, GPS1, and PMA derived by combining with the Gaia DR1 space data. Assuming the systematic differences of stellar proper motions of two catalogues to be caused by the mutual solid-body rotation and glide of the coordinate systems produced by the data of…
On the horizontal currents over the Martian magnetic cusp
Withers, Paul; Majeed, Tariq; AlMutawa, Shahd A. +4 more
Localized crustal magnetization over heavily cratered southern hemisphere at Mars gives rise to open magnetic field configurations which interact with the solar wind magnetic field to form magnetic cusp. The downward acceleration of energetic electrons in these cusps can produce aurora and an extended topside ionospheric structure over regions of …
Refined fundamental parameters of Canopus from combined near-IR interferometry and spectral energy distribution
Millour, F.; Zorec, J.; Domiciano de Souza, A. +3 more
Context. Canopus, the brightest and closest yellow supergiant to our Solar System, offers a unique laboratory for understanding the physics of evolved massive stars.
Aims: We aim at quantitatively exploring a large space of fundamental parameters of Canopus based on the combined analysis of its spectral energy distribution (SED) and optical-I…
Study of Galactic structure using UVIT/AstroSat star counts
Pradhan, Ananta C.; Ghosh, S. K.; Piridi, Sonika +3 more
The structure of our Galaxy has been studied from ultraviolet (UV) star counts obtained with the Ultra-Violet Imaging Telescope (UVIT) on board the AstroSat satellite, in Far-UV (FUV) and Near-UV (NUV) bands. The F154W (BaF2) and N263M (NUVB4) filters were used in the FUV and NUV bands, respectively. The point sources are separated from…
D Multi-Resolution Mapping of Mars Using Casp-Go on HRSC, Crism, Ctx and Hirise
Conway, S. J.; Tao, Y.; Muller, J. -P. +1 more
Automated large-scale retrieval of stereo photogrammetric DTMs of Mars fall into three categories: use of COTS software such as BAE-SOCET®; private software such as the DLR-VICAR software suite and open source solutions such as the NASA Ames Stereo Pipeline (ASP). We describe here a novel open source system developed on the back of ASP kno…
Exploiting night-time averaged spectra from PFS/MEX shortwave channel. Part 2: Near-surface CO retrievals
Vandaele, Ann Carine; Daerden, Frank; Nardi, Luca +7 more
Because of its important role in the Martian carbon cycle, carbon monoxide (CO) has been the subject of many measurements from ground and from space. Daytime measurements have been mostly exploited to measure the CO abundance because of their good signal-to-noise ratio, but night-time observations have not been documented yet. We demonstrate here …