The onset of photometric variability in red giant stars.
The onset of variability in red giant stars is studied from the datacollected by the `Long-Term Photometry of Variables' project whichoperates at ESO (La Silla) since 1982. The differential nature of theobservations combined with a multi-night reduction algorithm enables tostudy the variability of over 50 red giants with an accuracy of theorder of 2 to 3 millimagnitudes on time scales ranging from days toyears. All red giants with spectral types late G to early K (i.e.b-y~0.6-0.8) are stable at the level σ_y_<6millimag (whereσ_y_ is the standard deviation of the Stroemgren y magnitude). Redgiants with later spectral types are all variable, and it is found thatthe minimum variability level σ_y, min_ increases with increasingb-y, thus defining a minimum-variability boundary. The new data obtainedin this paper reveal that the time scale of the associated variabilityincreases with increasing b-y (and thus amplitude), and that thestability of this time scale improves concomitantly. More precisely,irregular variations on time scales of 5 to 10-days (andσ_y_~7millimag) characterize red giants with b-y~1.0, whereas thevariations (with σ_y_~100millimag) become more regular withperiods of the order of 50d for red giants with b-y~1.3. Aradial-velocity jitter (of the order of 1.5km/s r.m.s.) is associatedwith this photometric variability, and suggests that stellaroscillations may be responsible for the observed variations.
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Vitesses radiales. Catalogue WEB: Wilson Evans Batten. Subtittle: Radial velocities: The Wilson-Evans-Batten catalogue.
We give a common version of the two catalogues of Mean Radial Velocitiesby Wilson (1963) and Evans (1978) to which we have added the catalogueof spectroscopic binary systems (Batten et al. 1989). For each star,when possible, we give: 1) an acronym to enter SIMBAD (Set ofIdentifications Measurements and Bibliography for Astronomical Data) ofthe CDS (Centre de Donnees Astronomiques de Strasbourg). 2) the numberHIC of the HIPPARCOS catalogue (Turon 1992). 3) the CCDM number(Catalogue des Composantes des etoiles Doubles et Multiples) byDommanget & Nys (1994). For the cluster stars, a precise study hasbeen done, on the identificator numbers. Numerous remarks point out theproblems we have had to deal with.
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Longterm Photometry of Variables at ESO - Part Two - the Second Data Catalogue 1986-1990
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1993A&AS..102...79S&db_key=AST
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Four-colour photometry of the double-mode Cepheid EW Scuti
uvby observations of the double-mode Cepheid EW Scuti are presented, andthe first photoelectric light curves related to the two periods P0 =5.8232 + or - 0.0002 d and P1 = 4.0673 + or - 0.0002 d are provided. Afrequency analysis of the data yields an adequate solution for the lightvariation of EW Sct.
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Long-term photometry of variables at ESO. I - The first data catalogue (1982-1986)
This paper presents the catalog of photometric data in the Stromgrensystem obtained during the first four years (October 1982 - September1986) of the Long-Term Photometry of Variables (LTPV) program at ESO.The data are available in computer-readable form.
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Einstein Observatory magnitude-limited X-ray survey of late-type giant and supergiant stars
Results are presented of an extensive X-ray survey of 380 giant andsupergiant stars of spectral types from F to M, carried out with theEinstein Observatory. It was found that the observed F giants orsubgiants (slightly evolved stars with a mass M less than about 2 solarmasses) are X-ray emitters at the same level of main-sequence stars ofsimilar spectral type. The G giants show a range of emissions more than3 orders of magnitude wide; some single G giants exist with X-rayluminosities comparable to RS CVn systems, while some nearby large Ggiants have upper limits on the X-ray emission below typical solarvalues. The K giants have an observed X-ray emission level significantlylower than F and F giants. None of the 29 M giants were detected, exceptfor one spectroscopic binary.
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Visual multiples. VIII - 1000 MK types
A total of 1000 new classifications are given for stars brighter than B= 8.0 mag in the Aitken double star catalog. The classificationssupplement 865 classifications obtained in 1981 and 1984. Among thenewly discovered stars are 12 new Ap stars, eight Lambda Bootis stars,one Ba II star, and 60 Am stars. A detailed list of the newclassifications is given.
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The stellar component of the galaxy as seen by the AFGL infrared sky survey
The noise-limited magnitudes for the Air Force Geophysical Laboratory(AFGL) Infrared Sky Survey have been estimated by direct comparison withground-based observations. Using these limiting magnitudes, 'pruned'versions of the AFGL catalog have been generated. Infrared observationsof all the stellar objects seen at 11, 20, or 27 microns and astatistical sample of the stars seen only at 4 microns are reported.Analysis of the observations leads to estimates of the absolute 4 and 10microns magnitudes and space densities for the two clases of objects.The expected results from the Infrared Astronomical Satellite arereexamined.
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The proper motions of Struve double stars
The proper motions of the components of 103 Struve double stars fromMuller's list of neglected stars and of 15 other systems were measuredrelative to sets of reference stars, for the primary purpose ofdistinguishing physical from optical pairs. A by-product of thisinvestigation is a list of measured position angles and distances ofthese objects, at two epochs each.
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Colors of bright stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1954AJ.....59..228E&db_key=AST
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INHABITED SKY
