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The extremely young open cluster NGC 6611: Compiled catalogue, absorption map and the HR diagram
Piskunov, A. E.; Kharchenko, N. V.; Schilbach, E. +1 more
A compiled catalogue of astrometric and photometric data for about 2200 stars down to V=16.8() m is presented. The stars are located in an area with a radius of 22.8 arcmin around the extremely young open cluster NGC 6611 with the cluster center at (alpha ,delta )_{2000.0}=18() h18() m40() s,-13(deg) 47.1'. The catalogue is based on new reductions…
I- and JHK-band photometry of classical Cepheids in the HIPPARCOS catalog
Groenewegen, M. A. T.
By correlating the \cite[Fernie et al. (1995)]{F95} electronic database on Cepheids with the ``resolved variable catalog'' of the hipparcos mission and the simbad catalog one finds that there are 280 Cepheids in the hipparcos catalog. By removing W Vir stars (Type ii Cepheids), double-mode Cepheids, Cepheids with an unreliable solution in the hipp…
Understanding A-type supergiants. I. Ultraviolet and visible spectral atlas
Talavera, A.; Verdugo, E.; Gómez de Castro, A. I.
This paper is the first of a series whose aim is to perform a systematic study of A-type supergiant atmospheres and winds. Here we present a spectral atlas of 41 A-supergiants observed by us in high and medium resolution in the visible and ultraviolet. The atlas consists of profiles of the Hα , Hβ , Hγ , Hdelta , Hepsilon , Ca II (H and K), Na I (…
Relative intensity calibration of CDS-GIS detectors on SOHO using a plasma diagnostic technique
Landini, M.; Del Zanna, G.; Landi, E. +3 more
The internal intensity calibration of the Coronal Diagnostic Spectrometer (CDS) - Grazing Incidence Spectrometer (GIS) is studied using the Arcetri diagnostic method. A large number of spectral lines observed by the four GIS detectors in solar active and quiet regions is analysed in order to determine the relative intensity calibration curve of th…
Period-Luminosity-Colour distribution and classification of Galactic oxygen-rich LPVs. I. Luminosity calibrations
Luri, X.; Mennessier, M. O.; Alvarez, R. +1 more
The absolute K magnitudes and kinematic parameters of about 350 oxygen-rich Long-Period Variable stars are calibrated, by means of an up-to-date maximum-likelihood method, using Hipparcos parallaxes and proper motions together with radial velocities and, as additional data, periods and V-K colour indices. Four groups, differing by their kinematics…
Construction of the TYCHO Reference Catalogue
Makarov, V. V.; Lindegren, L.; Bastian, U. +5 more
The Tycho Reference Catalogue (TRC) project, as proposed in 1992 by the present authors, aimed to extend the Hipparcos reference system to fainter magnitudes. To assure rigidity of the reference system realization, the project relied on the Tycho Catalogue that provides highly-accurate positions of more than one million stars on the Hipparcos syst…
Mining in the HIPPARCOS raw data
Mignard, F.; Falin, J. L.
The Hipparcos solutions flagged as unreliable after the completion of the standard data processing have been systematically revisited in the light of additional information, primarily related to their multiplicity. In many cases improved solutions have been obtained, yielding at the same time an Hipparcos based separation and position angle and a …
Spectroscopy of the post-AGB star HD 101584 (IRAS 11385-5517)
Pottasch, S. R.; García-Lario, P.; Parthasarathy, M. +2 more
From an analysis of the spectrum (4000 Ä to 8800 Ä) of HD 101584 it is found that most of the neutral and single ionized metallic lines are in emission. The forbidden emission lines of [OI] 6300 Ä and 6363 Ä and [CI] 8727 Ä are detected, which indicate the presence of a very low excitation nebula. The Hα , FeII 6383 Ä, NaI D1, D2
Variable central stars of young Planetary Nebulae. A photometric study of the central star of M 2-54
Handler, G.
We acquired 63.8 hours of time-series photometry of the variable central star of the young Planetary Nebula M 2-54. This object exhibits light variations with a peak-to-peak amplitude of up to 0.3 mag in Johnson V. Two different time scales (several days and several hours) are present. While the long-term variations appear to be nonperiodic, the s…
The HIPPARCOS transit data: What, why and how?
Lindegren, L.; Quist, C. F.
The Hipparcos Transit Data are a collection of partially reduced, fully calibrated observations of (mostly) double and multiple stars obtained with the ESA Hipparcos astrometry satellite. The data are publicly available, as part of the CD-ROM set distributed with the Hipparcos and Tycho Catalogues \cite[(ESA SP-1200, 1997)]{hip}, for about a third…