Search Publications
Development of Active Regions: Flows, Magnetic-Field Patterns and Bordering Effect
Ishikawa, R.; Getling, A. V.; Buchnev, A. A.
A qualitative analysis is given of the data on the full magnetic and velocity vector fields in a growing sunspot group, recorded nearly simultaneously with the Solar Optical Telescope on the Hinode satellite. Observations of a young bipolar subregion developing within AR 11313 were carried out on 9 - 10 October 2011. Our aim was to form an idea ab…
Infrared and Ultraviolet Spectra of Methane Diluted in Solid Nitrogen and Irradiated with Electrons during Deposition at Various Temperatures
Chin, Chih-Hao; Chen, Sian-Cong; Liu, Meng-Chen +2 more
We recorded the infrared and ultraviolet absorption spectra of CH4:N2 matrix samples that underwent electron bombardment during deposition in the temperature range of 10-44 K. In contrast to a previous experiment on the IR spectroscopy of electron-bombarded icy samples, methyl and azide radicals became the main products upon …
In situ observations of waves in Venus's polar lower thermosphere with Venus Express aerobraking
Svedhem, Håkan; Bruinsma, Sean; Marty, Jean-Charles +1 more
The final stage of the Venus Express mission involved aerobraking — or deceleration by atmospheric drag — through the upper atmosphere above the northern pole of Venus. Concurrent measurements revealed two kinds of waves.
Major substructure in the M31 Outer Halo: the East Cloud
Mackey, A. D.; Martin, N. F.; Ferguson, A. M. N. +8 more
We present the first detailed analysis of the East Cloud, a highly disrupted diffuse stellar substructure in the outer halo of M31. The core of the substructure lies at a projected distance of ∼100 kpc from the centre of M31 in the outer halo, with possible extensions reaching right into the inner halo. Using Pan-Andromeda Archaeological Survey ph…
A new pattern in Saturn's D ring created in late 2011
Hedman, M. M.; Showalter, M. R.
Images obtained by the Cassini spacecraft between 2012 and 2015 reveal a periodic brightness variation in a region of Saturn's D ring that previously appeared to be rather featureless. Furthermore, the intensity and radial wavenumber of this pattern have decreased steadily with time since it was first observed. Based on analogies with similar stru…
A Search for Very Low-luminosity Objects in Gould Belt Clouds
Kim, Gwanjeong; Kim, Mi-Ryang; Lee, Chang Won +3 more
We present the results of a search for Very Low-Luminosity Objects (VeLLOs) in the Gould Belt (GB) clouds using infrared and sub-millimeter (sub-mm) data from 1.25 to 850 µm and our {{{N}}}2{{{H}}}+ (J = 1-0) observations. We modified the criteria by Dunham et al. to select the VeLLOs in the GB clouds, finding 95 VeLLO …
Chemical compositions and kinematics of the Hercules stream
Lambert, David L.; Reddy, Bacham E.; Ramya, P. +1 more
An abundance analysis is reported of 58-K giants identified by Famaey et al. (2005, A&A, 430, 165) as highly probable members of the Hercules stream selected from stars north of the celestial equator in the Hipparcos catalogue. The giants have compositions spanning the interval [Fe/H] from -0.17 to +0.42 with a mean value of +0.15 and relative…
Long-term R and V-band monitoring of some suitable targets for the link between ICRF and the future Gaia celestial reference frame
Souchay, J.; Taris, F.; Andrei, A. +3 more
Context. The Gaia astrometric mission of the European Space Agency was launched on December 2013. It will provide a catalog of 500 000 quasars. Some of these targets will be chosen to build an optical reference system that will be linked to the International Celestial Reference Frame (ICRF). The astrometric coordinates of these sources will have r…
Electric sail option for cometary rendezvous
Janhunen, Pekka; Quarta, Alessandro A.; Mengali, Giovanni
The recent successes of the European Rosetta mission have shown the possibility of a close observation with one of the most evasive celestial bodies in the Solar System, the comets, and the practical feasibility of a comet rendezvous to obtain detailed information and in situ measurements. This paper discusses a preliminary study of the transfer t…
InSight coordinates determination from direct-to-Earth radio-tracking and Mars topography model
Le Maistre, Sébastien
The InSight mission is planned to land on the surface of Mars in September 2016. Close to the equator in Elysium Planitia, in the vicinity of the Curiosity location, the exact landing site coordinates cannot be provided by the navigation team. The direct-to-Earth (DTE) Doppler measurements are rarely included in the early lander localization proce…