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Identifying and Tracking of Peripheral and Central Umbral Dots
Yang, Yunfei; Ji, Kaifan; Feng, Song +3 more
Umbral dots (UDs) are small isolated brightening observed in sunspot umbrae. They are usually classified into peripheral UDs (PUDs) and central UDs (CUDs) according to their positions inside an umbra. To accurately investigate the similarities and the distinctions between PUDs and CUDs and better understand their formation mechanisms, we propose a…
Dynamics of CMEs in the LASCO Field of View
Gopalswamy, N.; Bronarska, K.; Michalek, G. +1 more
A large set (16 000) of coronal mass ejections (CMEs) observed during 1996 - 2011 was selected to study their dynamics in the LASCO field of view (LFOV). These events were selected based on the criterion that at least three height-time measurements were available for each CME. The height-time measurements included in the SOHO/LASCO catalog were us…
Sources of Local Time Asymmetries in Magnetodiscs
Jackman, C. M.; Khurana, K. K.; Kane, M. +2 more
The rapidly rotating magnetospheres at Jupiter and Saturn contain a near-equatorial thin current sheet over most local times known as the magnetodisc, resembling a wrapped-up magnetotail. The Pioneer, Voyager, Ulysses, Galileo, Cassini and New Horizons spacecraft at Jupiter and Saturn have provided extensive datasets from which to observationally …
Observations of free-free and anomalous microwave emission from LDN 1622 with the 100 m Green Bank Telescope
Dickinson, C.; Cleary, K.; Harper, S. E.
LDN 1622 has previously been identified as a possible strong source of dust-correlated anomalous microwave emission (AME). Previous observations were limited by resolution meaning that the radio emission could not be compared with current generation high-resolution infrared data from Herschel, Spitzer or Wide-field Infrared Sky Explorer. This pape…
Determination of parameters of Long-Term variability of the X-ray pulsar LMC X-4
Lutovinov, A. A.; Falanga, M.; Molkov, S. V.
We have investigated the temporal variability of the X-ray flux measured from the high-mass X-ray binary LMCX-4 on time scales from several tens of days to tens of years, i.e., exceeding considerably the orbital period (~1.408 days). In particular, we have investigated the 30-day cycle of modulation of the X-ray emission from the source (superorbi…
Far-infrared signatures and inner hole sizes of protoplanetary discs undergoing inside-out dust dispersal
Robitaille, Thomas; Owen, James; Ercolano, Barbara +1 more
By means of radiative transfer simulation, we study the evolution of the far-infrared colours of protoplanetary discs undergoing inside-out dispersal, often referred to as transition discs. We show that a brightening of the mid- and far-infrared emission from these objects is a natural consequence of the removal of the inner disc. Our results can …
Decameter U-burst Harmonic Pair from a High Loop
Rucker, H. O.; Panchenko, M.; Poedts, S. +6 more
The results of the first observations of solar sporadic radio emission within 10 - 70 MHz by the Giant Ukrainian Radio Telescope (GURT) are presented and discussed. Observations in such a wide range of frequencies considerably facilitate the registration of harmonic pairs. The solar U-burst harmonic pair observed on 8 August 2012 is analyzed. The …
Multiwavelength observations of NaSt1 (WR 122): equatorial mass loss and X-rays from an interacting Wolf-Rayet binary
Van Dyk, Schuyler D.; Smith, Nathan; Close, Laird M. +5 more
NaSt1 (aka Wolf-Rayet 122) is a peculiar emission-line star embedded in an extended nebula of [N II] emission with a compact dusty core. The object was previously characterized as a Wolf-Rayet (WR) star cloaked in an opaque nebula of CNO-processed material, perhaps analogous to η Car and its Homunculus nebula, albeit with a hotter central source. …
Intensity of nightside MARSIS AIS surface reflections and implications for low-altitude ionospheric densities
Gurnett, D. A.; Němec, F.; Morgan, D. D. +1 more
Spacecraft radar sounding signals at frequencies higher than the ionospheric peak plasma frequency are not reflected by the ionosphere. Instead, they make it to the ground where they are reflected by the planetary surface. We analyze the intensity of the surface reflections measured by the Mars Advanced Radar for Subsurface and Ionosphere Sounding…
The Q/U Imaging Experiment: Polarization Measurements of the Galactic Plane at 43 and 95 GHz
Davies, R. D.; Dickinson, C.; Eriksen, H. K. +39 more
We present polarization observations of two Galactic plane fields centered on Galactic coordinates (l, b) = (0°, 0°) and (329°, 0°) at both Q (43 GHz) and W bands (95 GHz), covering between 301 and 539 square degrees depending on frequency and field. These measurements were made with the QUIET instrument between 2008 October and 2010 December, and…