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Spectrophotometry of speckle binary stars II
Al-Wardat, M. A.
Spectrophotometric observations of a second set consisting of 15 stars of speckle interferometric binaries are presented. Observations covered the range 3700-8100 Å, with a resolution of 18 Å. Results are presented in the form of the measured flux corrected for atmospheric extinction in the units of erg/cm2\cdot s \cdot Å, with no corre…
The origin of [FeII] emission in NGC4151
Chapman, Scott; Lee, David; Turner, James E. H. +5 more
The centre of NGC4151 has been observed in the J band with the SMIRFS integral field unit (IFU) on the UK Infrared Telescope. A map of [FeII] emission is derived, and compared with the distributions of the optical narrow-line region and radio jet. We conclude that, because the [FeII] emission is associated more closely with the visible narrow-line…
Time-resolved ultraviolet spectroscopy of the compact interacting binary QU Car
Long, K. S.; Drew, J. E.; Hartley, L. E.
We present Hubble Space Telescope STIS (1160-1700 Å) echelle spectra of the cataclysmic variable (CV) star QU Car, at three epochs. In catalogues this binary is classified as a nova-like variable. QU Car was observed three times in time-tag mode for 2300, 2600 and 2600 s, allowing us to study the spectral time evolution on time-scales down to ~10 …
Capella: Separating the Giants
Young, P. R.; Dupree, A. K.
Images from the Faint Object Camera (FOC) on the Hubble Space Telescope (HST) are used to spatially separate the two giants of Capella (α Aurigae; HD 34029) for the first time at ultraviolet wavelengths. The images were obtained with broadband filters that isolate the wavelength regions 2500-3000 Å and 1300-1500 Å. The cool G8 giant is found to be…
On stellar encounters and their effect on cometary orbits in the Oort cloud
Grothues, H. -G.; Serafin, R. A.
We systematically investigate the encounters between the Sun and neighbouring stars and their effects on cometary orbits in the Oort cloud, including the intrinsic one with the star Gl 710 (HIP 89 825), with some implications to stellar and cometary dynamics. Our approach is principally based on the combination of a Keplerian-rectilinear model of …
Energetic ions observed by Ulysses in the Jovian magnetosheath
Karanikola, I.; Anagnostopoulos, G.
In this paper we present a survey of energetic (>∼50 keV) ion and (>∼40 keV) electron measurements made in the Jovian magnetosheath by the (Heliospheric Instrument for Spectra, Composition and Anisotropy at Low Energies) experiment onboard Ulysses, during its flyby of Jupiter in February 1992. The most common characteristics of the magnetosh…
A quantitative research on the classification of coronal mass ejections
Dai, Yu; Zong, Wei-guo; Tang, Yu-hua
It is widely accepted that the properties of coronal mass ejections (CMEs) depend strongly on their structure. Hence it is important, in the study of solar-terrestrial events, to classify CMEs of different morphologies according to intensity. The method of fuzzy comprehensive evaluation can be applied to quantitative research of the CMEs. The memb…
Systematic Errors of High–Precision Photometric Catalogues
Mironov, Aleksey; Zakharov, Andrey
A very accurate imitation of Hipparcos and Tycho Hp, BT, andVT magnitudes was made using W, B, V, R magnitudes from the Tien Shan photometric catalogue. The calculated magnitudes were compared to the observed ones. It is shown that there are systematic differences between calculated and observed magnitudes. The systematic err…
Small Field CCD Astrometry with a Long Focus Reflector Telescope
Calderón, J. H.; Bustos Fierro, I. H.
We discuss the use of the block adjustment method for determining astrometric positions from a mosaic of CCD frames taken with a long focus reflector telescope. The observations cover an area of 25 arcmin × 25 arcmin around the open cluster Rup21. The source of reference positions was the Tycho-2 Catalogue. The internal error in the measured posit…
Contribution of HIPPARCOS to the Determination of Precession
Vityazev, V. V.
The IAU (1976) luni-solar precession constant was derived by Fricke from intensive study of the catalog of 512 FK4-FK4/Sup distant stars. At present, when the data from the catalog HIPPARCOS is available, it is helpful to reconsider Fricke's analysis. This paper presents a redetermination of precession based on the following new factors: (a) the a…