Search Publications
Geomorphological Evidence of Localized Stagnant Ice Deposits in Terra Cimmeria, Mars
Hauber, Ernst; Jaumann, Ralf; Fawdon, Peter +3 more
The presence of snow and ice at midlatitudes of Mars cannot be explained by current climatic conditions, as surface ice is unstable. However, a large variety of debris-covered glaciers have been observed at both midlatitudes. Here, we report the presence of local, small-scale, and debris-covered stagnant ice deposits on the floor of a valley syste…
Variation of coronal holes latitudinal distribution: Correction of limb brightening of EUV coronal images
Chargeishvili, B. B.; Maghradze, D. A.; Japaridze, D. R. +4 more
We studied the limb brightening of SOHO EIT daily images of the solar corona taken in 195 Å wavelength line from 1996 to 2018. Using special software, we studied the distribution of the background intensity of the entire disk in the direction of rotation (horizontally) and perpendicular to the direction of rotation (vertical). The study shows that…
2FHL J0826.1-4500: Discovery of a Possible Shock-Cloud Interaction on the Western Edge of the Vela Supernova Remnant
Ajello, M.; Tibaldo, L.; Marchesi, S. +3 more
We report on the investigation of a very high-energy, Galactic γ-ray source recently discovered at >50 GeV using the Large Area Telescope on board Fermi. This object, 2FHL J0826.1-4500, displays one of the hardest >50 GeV spectra (photon index Γ γ ∼ 1.6) in the 2FHL catalog, and a follow-up observation with XMM-Newton has uncover…
HD 42659: the only known roAp star in a spectroscopic binary observed with B photometry, TESS, and SALT
Holdsworth, Daniel L.; Saio, Hideyuki; Kurtz, Donald W.
We present a multi-instrument analysis of the rapidly oscillating Ap (roAp) star HD 42659. We have obtained B photometric data for this star and use these data, in conjunction with the Transiting Exoplanet Survey Satellite (TESS) observations, to analyse the high-frequency pulsation in detail. We find a triplet that is split by the rotation freque…
Post-rendezvous radar properties of comet 67P/CG from the Rosetta Mission: understanding future Earth-based radar observations and the dynamical evolution of comets
Kofman, Wlodek; Heggy, Essam; Palmer, Elizabeth M. +2 more
Radar observations provide crucial insights into the formation and dynamical evolution of comets. This ability is constrained by our knowledge of the dielectric and textural properties of these small-bodies. Using several observations by Rosetta as well as results from the Earth-based Arecibo radio telescope, we provide an updated and comprehensiv…
Infrared Spectroscopy of the Recent Outburst in V1047 Cen (Nova Centauri 2005)
Udalski, A.; Mróz, P.; Munari, U. +14 more
Fourteen years after its eruption as a classical nova (CN), V1047 Cen (Nova Cen 2005) began an unusual re-brightening in 2019 April. The amplitude of the brightening suggests that this is a dwarf nova (DN) eruption in a CN system. Very few CNe have had DN eruptions within decades of the main CN outburst. The 14 yr separating the CN and DN eruption…
2MASS J10274572+0629104: the very short period young M6 dwarf binary system identified in K2 data
Burgasser, A. J.; Gizis, J. E.; Paudel, R. R. +1 more
We report the identification of a very low mass new binary system 2MASS J10274572+0629104, based on Kepler K2 photometry and Gaia DR2 astrometry. It is located at a distance of 90.0 ± 2.9 pc. The K2 light curve is consistent with a beat pattern of two periodic signals, and using Lomb-Scargle periodogram, we find two rotation periods of 0.2114 ± 0.…
PY Boo and NSVS 7328383: Two totally-eclipsing W UMa stars with small mass ratios and close parameters
Popov, Velimir A.; Petrov, Nikola I.; Kjurkchieva, Diana P.
Photometric observations of the W UMa binaries PY Boo and NSVS 7328383 with periods of around 0.27 d are presented. The light curve solutions reveal that the components of both targets are stars of K type (temperatures T1=4770 K, T2=5080 K and T1=5146 K, T2=5056 K, respectively,) and undergo total eclips…
Measurement of plasma channels in the Venus wake
Lundin, R.; Futaana, Y.; Zhang, T. L. +1 more
Plasma channels have been suggested to account for the observation of ionospheric holes in the Venus nightside ionosphere. They are produced by the erosion of the solar wind on the magnetic polar regions of the Venus ionosphere, and are related to a sharp plasma transition that extends along the flanks of the wake and that is located downstream fr…
A statistical study of CME-associated flare during the solar cycle 24
Beheary, M. M.; Shaltout, Abdelrazek M. K.; Amin, Eid A. +1 more
We investigate on the relationship between flares and coronal mass ejections (CMEs) in which a flare started before and after the CME events which differ in their physical properties, indicating potentially different initiation mechanisms. The physical properties of two types flare-correlated CME remain an interesting and important question in spa…