Study of Neglected Variable Stars Classified as Type II Cepheids
Four variable stars classified as Type II Cepheids have been studiedpartly based on new photometry and the Hipparcos photometric data. Thecorrect period is derived for V341 Ara and NW Pav and it is pointed outthat RR Mic and V1711 Sgr do not belong to Type II Cepheids, insteadthey may be semi-regular variables. The cycle length of theirvariability is also determined.
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Far-Ultraviolet Stellar Photometry: Fields Centered on rho Ophiuchi and the Galactic Center
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996ApJS..104..101S&db_key=AST
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Far-ultraviolet stellar photometry: Fields in Sagittarius and Scorpius
Far-ultraviolet photometry for 741 objects in a field in Sagittariuscentered near M8 and 541 objects in a field centered near sigma Scorpiiis presented. These data were extracted from electographic imagesobtained with two cameras during a shuttle flight in 1991 April/May. Thecameras provided band passes with lambdaeff = 1375 A andlambdaeff = 1781 A. Synthetic colors show that these bandsare sensitive to effective temperature for hot stars. Our measurementswere placed on a quantitative far-ultraviolet magnitude scale byconvolving the spectra of stars observed by IUE with our cameras'spectral response functions. Fifty-eight percent of the ultravioletobjects were identified with visible stars using the SIMBAD databasewhile another 40% of the objects are blends of early type stars tooclose together to separate with our resolution. Our photometry iscompared with that from the TD-1, OAO 2, and ANS satellites and the S201(Apollo 16) far-ultraviolet camera and found to agree at the level of afew tenths of a magnitude. Unlike previous studies, almost half of theidentified visual counterparts to the ultraviolet objects are early Bstars. A plot of distance modulus against ultraviolet color excessreveals a significant population of stars with strong ultravioletexcess.
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Secondary UVBY standards in the Harvard E-regions
Photoelectric uvby photometry for 201 stars which are already UBV (RI)cstandards is presented. The photoelectric data are closely tied to theCousins uvby standards and the stars should be suitable for use asfainter (7-11 mag) secondary standards.
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Secondary standards for H-beta photometry in the Southern Hemisphere (second series).
Not Available
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The zero point of the Cepheid period-luminosity relation in the 1.05 micron wave band
New observations of the Cepheids in the galactic clusters and externalgalaxies LMC, NGC 6822, NGC 300, and Sex A in the 1.05-micron wave band(IV) are presented. The slope of the P-L(IV) relation derived from theCepheids in the LMC agree with that in the SMC and that obtained forGalactic Cepheids. The zero point of the relation has been determinedfrom the distances to the galactic Cepheid clusters obtained throughZAMS fitting and referenced to the Pleiades modulus of 5.57. Thebolometric P-L relations derived individually using the data in V, J, Kwave bands are found to have the same slope and the zero point asobserved in the IV wave band. The comparison of the bolometric P-Lrelation with that obtained theoretically by Becker, Iben, and Tuggleshows agreement in the value of the slope. But the theoreticalmagnitudes are brighter by 0.4 mag. The true distance moduli to the LMC,the SMC, NGC 6822, NGC 300, and Sex A have been derived from P-L(IV)data and are found to be as 18.42, 18.83, 23.18, 25.72, and 25.27,respectively.
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The distance and structure of the Coalsack. I - Photometric data
The results of UBV and H-beta photometry for 284 stars of spectral typesB to F located in the area of the dark cloud Coalsack are presented.Most of the present stars are brighter than 10.0 mag and are classifiedin the MK system of Houk and Cowley (1975). For each star, the bestvalues for the extinction and distance modulus are provided, withtypical estimated errors of + or - 0.08 mag for the extinction and + or- 0.32 mag for the distance modulus. Possible misclassifications andspectral peculiarities are noted for several of the stars.
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UBV (RI)c standard stars in the E- and F-regions and in the Magellanic Clouds - a revised catalogue.
Not Available
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UBV photometry of E region standard stars of intermediate brightness
Photometry data are given for 335 stars in the nine E regions.Observations were made using a photometer and filters on the 47 cmreflector at Cape Town. The stellar dispersions are summarized. Data arepresented in tabular form.
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Photometric standard stars for the UBV and (RI)KC systems.
Not Available
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Fainter Standards for VRI Photometry in the E Regions
Not Available
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A photoelectric UBV sequence in the region of the wing of the Small Magellanic Cloud
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1978A&AS...33..107J&db_key=AST
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Photoelectric UBV standard sequences in neighbouring parts of the clusters NGC 6256, 6304, 6638 - integrated photometry of NGC 4590, 6256, 6304, 6401, 6638.
Abstract image available at:http://adsabs.harvard.edu/abs/1976A&AS...25..281B
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Standard magnitudes in the E regions.
Not Available
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