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A lopsided chemically distinct nucleus in NGC 5055
Sil'chenko, O. K.; Afanasiev, V. L.
Kinematics and stellar population properties in the center of nearby Sbc galaxy NGC 5055 are studied with the Multi-Pupil Spectrograph of the 6 m telescope of the Special Astrophysical Observatory of Russian Academy of Sciences (SAO RAS). We confirm the rotation and stellar velocity dispersion asymmetries along the major axis reported earlier by o…
Nature of OH maser and SiO thermal emission towards carbon star: IRAS 05373-0810 (V1187 Ori)
Omont, A.; Szczerba, R.; Szymczak, M. +1 more
We present observational evidence that IRAS 05373-0810 is a genuine carbon star with an ISO SWS spectrum closely resembling that of R Scl. Modelling of the spectral energy distribution of IRAS 05373-0810 suggests that the star has luminosity of order of 8000 Lsun and loses mass at a rate of about 2-3*E-7 Msun yr
A study of opacity in SOHO-SUMER and SOHO-CDS spectral observations. III. The validity of the escape probability model
Fischbacher, G. A.; Loch, S. D.; Summers, H. P.
The assumptions underpinning escape probability and absorption factor methods for describing spectral emission from optically thick plasmas, are addressed to test the range of validity of the associated expressions and to develop them for use within non-stratified atmospheres which include plasma flow and line blending. It is found that for modera…
Lasers without inversion (LWI) in Space: A possible explanation for intense, narrow-band, emissions that dominate the visible and/or far-UV (FUV) spectra of certain astronomical objects
Sorokin, P. P.; Glownia, J. H.
The optical or far-UV (FUV) spectra of certain objects in Space are completely dominated by one or two spectrally narrow emission lines, strongly suggesting that laser action of some kind occurs in these objects. However, the electronic level structures of the atoms/ions producing these emissions preclude the possibility of maintaining population …
Identification of RR Lyrae stars in the Tycho-2 catalogue
Mennessier, M. O.; Colomé, J.
The Tycho-2 catalogue provides astrometric and photometric data for the 2.5 million brightest stars in the sky. Therefore it can provide much larger samples than the Hipparcos samples used to date in statistical studies. The object of this paper is the cross-identification of Tycho-2 sources and known variable stars of RR Lyrae type. The Tycho-2 d…
The radial velocities and physical parameters of HD 553
Iliev, L.; Iliev, I. Kh.; Duemmler, R.
Erratum: Radiation-driven winds of hot luminous stars. XIII. A Description of NLTE line blocking and blanketing towards realistic models for expanding atmospheres
Pauldrach, A. W. A.; Hoffmann, T. L.; Lennon, M.
We present significant improvements of our approach in constructing detailed atmospheric models and synthetic spectra for hot luminous stars: 1. A sophisticated and consistent description of line blocking and blanketing. Our solution concept renders the line blocking influence on the ionizing fluxes (mainly the EUV and UV are affected) in identica…
CCD astrometry of faint compact extragalactic radio sources. III.
Costa, E.
Optical positions relative to the Hipparcos Catalogue (ESA 1997) have been obtained for the optical counterparts of 38 faint (B ~ 20-24) southern compact extragalactic radio sources (CERS). Many of these sources are not detectable - or their coordinates not adequately measurable - by means of direct photography with a wide-field telescope, so the …
The multiple frequencies of the delta Scuti star V350 Peg
García-Melendo, E.; Lampens, P.; Vidal-Sáinz, J. +1 more
V350 Peg is a delta Scuti star discovered by Hipparcos (ESA \cite{esa97}). During 35 nights between July 1997 and December 2001 some 7500 CCD V observations were acquired at the Monegrillo and Esteve Duran observatories in Spain. The new data show that this star pulsates in a close doublet of frequencies separated by 0.17 c/d (Delta f/f=3%) with s…
Optical positions of 55 radio stars from astrolabe observations from the Yunnan Observatory
Hui, H.; Rui, W.
The observations by the photoelectric astrolabe at Yunnan Observatory relative to the Hipparcos Catalogue and the optical positions of 55 radio stars were obtained from observations between 1991 and 2000. They all resulted from processing the photon counts obtained by means of the astrolabe after the automation of the instrument. There are 46 star…