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Secondary photometric standard stars for the Thuan-Gunn and Johnson-Kron-Cousins systems
CCD photometry is presented for 119 stars observed in the Thuan-Gunnphotometric system (the passbands vgr). The sample includes 82 stars forwhich magnitudes in this system have not previously been published.Photometry in the Johnson-Kron-Cousins photometric system (BV or UBV)has been obtained for a subsample of 85 of the stars. Of those starswhich are not primary standard stars for the Thuan-Gunn system 70observed in Gunn r, 48 observed in Gunn g, and 37 observed in Gunn vhave sufficient repeat measurements that they may be used as secondarystandard stars for CCD photometry. The typical uncertainties for themagnitudes of these stars are 0.006 mag.
| UBV(RI)c photometry of equatorial standard stars - A direct comparison between the northern and southern systems
UBV(RI)c photometry of 212 stars from Landolt's list of equatorialstandards is presented. The observations are tied to the system definedby Cousin's E-region standards. A comparison of the present results withLandolt's reveals reasonably good agreement for (V-R)c and (V-I)c, butmarked systematic differences for (B-V) and (U-B). The UBV systems ofCousins and Landolt are evidently not the same and both probably differfrom Johnson's original system.
| UBV Photometry of Equatorial Stars
Not Available
| UBVRI photometric standard stars around the celestial equator
It is pointed out that accurate, internally consistent, and readilyaccessible standard star photometric sequences are necessary for thecalibration of the intensity and color data which astronomers obtain atthe telescope. The photometric results provided in connection with thepresent study represent the first part of an effort which is concernedwith the presentation of UBVRI photoelectric photometric standard starsin the magnitude range from 7 to 17 over as broad a range in color aspossible. All of the photometric observations were made with a 31034type photomultiplier used in a pulse counting mode. Some 15 to 25standard stars chosen from Cousins' lists (1973, 1976) in the E-regionswere observed with an 0.4-m telescope each night along with the programstars. UBVRI standard stars were observed periodically throughout thenight. Observations with a 0.9-m telescope were also conducted. TheUBVRI photoelectric observations take into account 223 stars.
| The globular cluster system of the Galaxy. I - The metal abundances and reddenings of 70 globular clusters from integrated light measurements
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1980ApJS...42...19Z&db_key=AST
| Distances to eclipsing binaries. III - Masses, radii, and absolute magnitudes of 96 stars
Distances to, and absolute magnitudes of, 96 components of eclipsingbinaries with well-determined absolute dimensions have been computedusing V-R photometry. The calculations take into account interstellarreddening, which is estimated from existing UBV and uvby-betaphotometry, as well as photometric proximity effects. The resultingabsolute magnitudes, dimensions, and masses are compared with zero-agemain sequences predicted by theory. Theory is in good agreement with theobserved data for stars more massive than the sun if a composition (X,Y, Z) = (0.66 + or - 0.03, 0.303 + or - 0.03, 0.037 + or - 0.005) ischosen. The corresponding helium-to-hydrogen number ratio is 0.115 + or- 0.02, in agreement with previous estimates.
| Spectral classifications for Landolt's celestial equatorial standard stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1979AJ.....84..783D&db_key=AST
| Equatorial UBVRI photoelectric sequences
From 1335 BVRI observations of 189 stars in selected areas 92-115,Landolt's (1973) network of faint UBV standards has been extended to RI. Of these stars, 173 have four or more observations. The (U-B) valuesof Landolt are adopted, and a well-observed equatorial faint-starnetwork is presented on the Johnson UBVRI photometric system.
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| Takýmyýldýz: | Baliklar |
| Sað Açýklýk: | 23h43m14.66s |
| Yükselim: | +00°54'16.7" |
| Görünürdeki Parlaklýk: | 8.595 |
| Uzaklýk: | 179.211 parsek |
| özdevim Sað Açýklýk: | -14.2 |
| özdevim Yükselim: | 3.9 |
| B-T magnitude: | 9.971 |
| V-T magnitude: | 8.709 |
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