Search Publications
The Multiple Pre-main-sequence System PR Ori and the Associated HH 305 Flow
Bally, J.; Raga, A. C.; Geballe, T. R. +6 more
A detailed imaging and spectroscopic analysis is presented of the little-studied T Tauri star PR Ori and its associated Herbig-Haro flow HH 305, located on the outskirts of the L1641-N cluster in Orion. PR Ori is shown to be a multiple system, where the A component is a close 0.″077 binary, and the B component, at a distance of 3.″50, is the drive…
A Refined Sample of Lyman Excess H II Regions
Kerton, C. R.; Marshall, Brandon
A large number (67) of the compact/ultra-compact H II regions identified in the Coordinated Radio and Infrared Survey for High-Mass Star Formation catalogue were determined to be powered by a Lyman continuum flux in excess of what was expected given their corresponding luminosity. In this study we attempt to reasonably explain the Lyman excess phe…
"Carte du Ciel" Catalogs and Their Importance for Modern Astrometry
Sementsov, V. N.
Astronomical catalogs created as a result of the "Carte du Ciel" project are considered, including the work of K.V. Kuimov in this area, its methodological importance, and perspectives in the GAIA era. This paper is based on a presentation made at the conference "Modern Astrometry 2017," dedicated to the memory of K.V. Kuimov (Sternberg Astronomic…
Spectral evolution of the two classical novae PW Vul and V1668 Cyg using International Ultraviolet Explorer low‑resolution spectra
Sanad, M. R.; Yousef, S.; Essam, A. +2 more
We studied the evolution of the normalized flux of selected ultraviolet (UV) emission lines of two classical novae (PW Vul and V1668 Cyg) using International Ultraviolet Explorer (IUE) short wavelength observations. Different phases of the outburst are studied. Emission lines covering a wide range of ionization states are investigated. We use the …
Large-scale magnetic fields and anomalies of chemical composition of stellar coronae
Pipin, V. V.; Tomozov, V. M.
We present evidence that anomalies in abundance of the chemical admixtures with the low first ionization potential (FIP) in the low corona of the late-type stars can be related to a topology of the large-scale magnetic field. Observational data from Ulysses and the Stanford Solar Observatory reveal the high correlations between the FIP effect of t…
3D Magnetic Holes in Collisionless Plasmas
Artemyev, A.; Vasko, I.; Yushkov, E. +1 more
Recent multispacecraft observations in the Earth's magnetosphere have revealed an abundance of magnetic holes—localized magnetic field depressions. These magnetic holes are characterized by the plasma pressure enhancement and strongly localized currents flowing around the hole boundaries. There are several numerical and analytical models describin…
Results of Processing of CCD Observations of Selected Open Clusters on Maidanak
Andruk, V. M.; Muminov, M. M.; Protsyuk, Yu. I. +4 more
Observations of 20 open clusters at the Maidanak Observatory were performed using the Zeiss-1000 telescope in the winter of 2018. As the light receiver, a CCD camera Apogee Alta U9000 (3K x 3K, FOV 19.5'x19.5') was used. All observations were performed using BVRI light filters. The exposure time, depending on the filter was from 60 to 150 seconds.…
Mapping and dating based evolution studies of the Niger Vallis outflow channel, Mars
Kostama, V. -P.; Kukkonen, S.
Niger Vallis is one of the four large outflow channel systems in the eastern Hellas rim region of Mars. Niger, as well as the other nearby valles, is assumed to have been carved by water and later covered by ice-rich deposits. Thus, it plays a significant role both in the fluvial and glacial evolution of the region. This work presents the photogeo…
Globular cluster population of the HST Frontier Fields galaxy J07173724+3744224
López-Cruz, Omar; Barkhouse, Wayne A.; Carlson, Nathan L. +4 more
We present the first measurement of the globular cluster (GC) population surrounding the elliptical galaxy J07173724+3744224 (z = 0.1546). This galaxy is located in the foreground in the field-of-view of the Hubble Space Telescope (HST) Frontier Fields observations of galaxy cluster MACS J0717.5+3745 (z = 0.5458). Based on deep HST Advanced Camera…
Enhanced Airglow Signature Observed at Titan in Response to its Fluctuating Magnetospheric Environment
Crary, F.; Wahlund, J. -E.; Esposito, L. W. +1 more
On rare occasions Titan has been observed in the magnetosheath, where the solar wind interferes with the regular magnetic field generated by Saturn. This particular orbital position allows for a deeper investigation of Titan's upper atmosphere response to its highly energetic magnetospheric environment. Although solar extreme ultraviolet radiation…