Search Publications
Astrometric study of the triple star ADS 9173
Kiyaeva, O. V.
An approximate orbit of the wide visual binary star ADS 9173 A(Bb) with a period of ∼6000 yr has been determined for the first time by the method of apparent motion parameters. The orbit was computed using a short (1982 2004) arc of photographic observations obtained with the 26-inch Pulkovo Observatory refractor and the Hipparcos parallax. Agreem…
An archival study of extended X-ray emission from classical and recurrent novae
Balman, Şölen
I discuss morphology and spectrum of the first resolved and detected classical nova shell in the X-rays - the remnant of GK Persei (1901). The existence of such a nebulosity brings about the possibility of other nova remnants emitting X-rays. I calculate that the X-ray luminosity should be about 10 26-10 33 ergs s -1
The separation of red horizontal branch giants from reduced proper motions
Rybka, S. P.
The possibility to use reduced proper motions for distinguishing red horizontal branch giants from foreground stars is substantiated. Our approach is developed on the basis of HIPPARCOS astrometric data and near-infrared 2MASS photometric data taken from the UCAC2 BSS catalogue. The application of maximum-likelihood technique to analyse the distri…
Optical and Infrared Nondetection of the z = 10 Galaxy behind Abell 1835
Smith, Graham P.; Egami, Eiichi; Eisenhardt, Peter R. +2 more
Gravitational lensing by massive galaxy clusters is a powerful tool for the discovery and study of high-redshift galaxies, including those at z>=6 likely responsible for cosmic reionization. Pelló et al. recently used this technique to discover a candidate gravitationally magnified galaxy at z=10 behind the massive cluster lens Abell 1835 (z=0.…
Multifractality in a ring of star formation: the case of Arp 220
de La Fuente Marcos, R.; de La Fuente Marcos, C.
Context: .Formation of super star-clusters can be triggered during the final stages of galaxy mergers or galactic interactions, when significant numbers of massive stars are formed out of large gas-cloud systems. Giant cloud complexes show a fractal structure due to turbulence and/or self-gravitation; therefore, super clusters formed out of these …
Theoretical Isochrones with Extinction in the K Band. II. J - K versus K
Lee, Myung Gyoon; Figer, Donald F.; Kim, Sungsoo S.
We calculate theoretical isochrones in a consistent way for five filter pairs near the J and K band atmospheric windows (J-K, J-K', J-Ks, F110W-F205W, and F110W-F222M) using the Padova stellar evolutionary models of Girardi et al. We present magnitude transformations between various K-band filters as a function of color. Isoc…
Productivity and Impact of Space-based Astronomical Facilities
Trimble, Virginia; Zaich, Paul; Bosler, Tammy
In 2001, 18 journals published about 1270 astronomical papers that reported and/or analyzed data gathered by space-based observatories and missions. These papers were cited 24,460 times in papers published in 2002-2004, an average of 19.26 citations per paper or 6.42 citations per paper per year (sometimes called impact or impact factor). About 60…
Kinematic control of the inertiality of the system of Tycho-2 and UCAC2 stellar proper motions
Bobylev, V. V.; Khovirtchev, M. Yu.
Based on the Ogorodnikov-Milne model, we analyze the proper motions of Tycho-2 and UCAC2 stars. We have established that the model component that describes the rotation of all stars under consideration around the Galactic y axis differs significantly from zero at various magnitudes. We interpret this rotation found using the most distant stars as …
HST BVI photometry of Triton and Proteus
Pascu, Dan; Rohde, James R.; Seidelmann, P. Kenneth +4 more
BVI photometry of Triton and Proteus was derived from HST images taken in 1997. The VEGAMAG photometric technique was used. Triton was found to be brighter by a few percent than observations of the 1970's and 1980's, as expected due to the increasingly greater exposure of the bright south polar region. The leading side was also found to be brighte…
Measurements of winds on Mars with Hubble Space Telescope images in 2003 opposition
Videen, G.; Kaydash, V. G.; Kreslavsky, M. A. +3 more
The winds of Mars at the water cloud level are measured by tracking cloud features in sequential high-resolution Hubble Space Telescope UV images for 5 days during the perihelion season in 2003. Global circulation model (GCM) predictions are in general agreement with the observations for the zonal wind component, but reveal significant differences…