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Search for Evolutionary Changes in the Periods of Cepheids: CF Cas
Berdnikov, L. N.; Pastukhova, E. N.
For the classical Cepheid CF Cas we have constructed an O- C diagram spanning a time interval of 129 years. The O- C diagram has the shape of a parabola, which has made it possible to determine for the first time the quadratic light elements and to calculate the rate of evolutionary decrease in the period, dP/ dt = -0.050 (±0.006) syr-1…
Energy‑dependent timing studies of the low‑hard state of black hole X‑ray binaries with XMM‑Newton
Kong, Albert K. H.; Stiele, Holger
Almost all low‑mass black hole X‑ray binaries are transient sources. Most of these sources show a hysteresis: they evolve from the low‑hard state through intermediate state(s) into the high‑soft state and then return to the hard state at lower luminosity, again passing through the intermediate states. However, there are outbursts that remain in th…
Discovery and Period Analysis of Seven Variable Stars
Polakis, T.
Tens of thousands of images have been acquired during the course of asteroid photometry observations at Command Module Observatory (MPC V02). Nightly sets of these images were analyzed using a software routine that locates field stars whose brightness shows anomalously high photometric scatter. A total of 32 variable stars were identified by this …
Venus crater-related radar-dark parabolas and neighboring terrains: A comparison of 1-µm emissivity and microwave properties
Basilevsky, A. T.; Markiewicz, W. J.; Shalygin, E. V. +2 more
This work presents a comparative study of microwave properties and 1-µm emissivity for five Venus crater-associated radar-dark parabolas along with neighboring plains and some other geologic units. Craters of interest are Adivar, Bassi, Bathsheba, Sitwell, and du Chatelet with nearby crater Caccini having non-parabolic radar-dark halo. Micro…
Spectroscopy of Globular Clusters in the Spheroidal Dwarf Galaxy IKN
Sharina, M. E.; Shimansky, V. V.
Moderate resolution spectra of four globular clusters in the dwarf spheroidal galaxy IKN obtained with the 6-m telescope of the Special Astrophysical Observatory have been used to determine the radial velocities, ages, and metallicities of the clusters, and also to derive the first approximate estimates of the abundances of Mg, Ca, and C. Cross-co…
Upper Limits for Emissions in the Coma of Comet 67P/Churyumov-Gerasimenko near Perihelion as Measured by Rosetta’s Alice Far-UV Spectrograph
Parker, Joel Wm.; Bertaux, Jean-Loup; Stern, S. Alan +13 more
The Alice far-UV imaging spectrograph (700-2050 Å) acquired over 70,000 spectral images during Rosetta’s 2 yr escort mission, including over 20,000 in the months surrounding perihelion when the comet activity level was highest. We have developed automated software to fit and remove ubiquitous H, O, C, S, and CO emissions from Alice spectra, along …
Oscillatory Flows in the Magnetotail Plasma Sheet: Cluster Observations of the Distribution Function
Gunell, H.; Nilsson, H.; Hamrin, M. +7 more
Plasma dynamics in Earth's magnetotail is often studied using moments of the distribution function, which results in losing information on the kinetic properties of the plasma. To better understand oscillatory flows observed in the midtail plasma sheet, we investigate two events, one in each hemisphere, in the transition region between the central…
CoRoT-18 b: Analysis of High-Precision Transit Light Curves with Starspot Features
Heras, A. M.; Gondoin, P.; Schmidt, T. O. B. +4 more
When a planet occults a spotty area on a stellar surface, the flux increases and a characteristic feature in a light curve - a bump - is observed. Among the planets detected by the CoRoT-mission CoRoT-18 is especially interesting as it exhibited spot crossings that we have analyzed in detail. We used four ground-based observations obtained at a 1.…
Gould Belt members in X-ray RAVE: cross-matching RAVE stars with 3XMM point sources
Özkan, M. T.; Plevne, O.; Coşkunoğlu, B.
In this paper the results of matching the RAdial Velocity Experiment (RAVE), a spectroscopic Southern hemisphere survey (
3C 294 revisited: Deep Large Binocular Telescope AO NIR images and optical spectroscopy
Quirrenbach, A.; Gredel, R.; Thompson, D. +11 more
Context. High redshift radio galaxies are among the most massive galaxies at their redshift, are often found at the center of protoclusters of galaxies, and are expected to evolve into the present day massive central cluster galaxies. Thus they are a useful tool to explore structure formation in the young Universe.
Aims: