The catalog is a compilation of photoelectric photometry in the Johnson UBVRI system published prior to mid-1984. The catalog contains a total of 6849 stars in the original Johnson system (Morel and Magnenat 1978), 467 stars in the system of Kunkel and Rydgren (1979), 1150 stars in the system of Moffett and Barnes III (1979), and 252 stars in the system of Neckel and Chini (1980). The catalog is in 14 files: The first 12 files list observational data, mean values, and references for each of the four standard systems. An additional two files contain the numbering scheme of Mermilliod (1978) used to identify objects, and introductory information.
Photoelectric UBV photometry is presented for a sample of 165 stars drawn from the extension of the HK objective-prism/interference-filter survey of Beers, Preston and Shectman (1985AJ.....90.2089B) to the northern galactic hemisphere. These results are part of continuing follow-up observations of candidate metal-deficient and horizontal-branch field stars and other interesting stars identified in the survey. A complete set of photometric observations is now available for three of the 25-square-degree survey fields. We estimate that the complete photometric sample of 299 northern HK candidates obtained to date contains on order 90 main-sequences turnoff, subgiant, and giant stars with [Fe/H]<=-1.0, 50 field blue horizontal-branch stars, and 30 stars with the photometric properties of field blue stragglers.
This is a catalogue contains photographically determined UBVr magnitudes for more than 13000 stars at high galactic latitude. Eight pieces of information are given for each star: identification number, approximate x and y coordinates as measured on the plates, V, B, U, r, and comments.
New observations from the southern hemisphere have been used to check the periods for the 11 RR Lyrae variables in and around the globular cluster Messier 9. The periods were determined previously with data from northern observatories where M9 can only be observed over a small range in hour angle. Three of the eleven published periods were found to be in error. As a result of this, the mean period of the RRc variables has been revised from 0.279d to 0.341d, the mean period of the RRab variables has been revised from 0.614d to 0.621d,and a star previously believed to be an RR Lyrae has been reclassified as a Population II Cepheid. One of the RRc variables may be a double-mode pulsator. Another variable was studied, but the data were not sufficient for determining its period.
Radii, b26 magnitudes, (b-r) colors, position angles, and ellipticities have been measured on the plates of Palomar 48-inch Schmidt telescope taken in May 1976, for 6925 galaxies in a 5-sq deg field enclosing the close pair of rich clusters A2197 and A2199.
NGC 6530 is a young cluster, with a complex morphology and star-formation history. We present a statistical study of its global properties, using a new, large list of candidate members down to masses of 0.2-0.4M_{sun}_ and Gaia DR2 astrometry. We consider a larger sky region compared to previous studies, to investigate the entire cluster until its periphery, including any diffuse population all around the main cluster. We study the distribution of extinction and age across the different regions, and obtain constraints on the star-formation history. We also study the dynamics of cluster members. Cluster membership was determined on the basis of literature X-ray data, H{alpha} emission, near-IR and UV excesses from the VPHAS+ and UKIDSS photometric surveys and published near-IR catalogs, and Gaia DR2 astrometry; moreover, we used a method for photometric selection of M-type pre-main-sequence cluster members, which we recently developed and used for other star-formation regions. The list of candidates includes nearly 3700 stars, of which we estimate approximately 2700 to be genuine NGC 6530 members. Using Gaia parallaxes, the cluster distance is found to be 1325pc, with errors of 0.5% (statistical) and 8.5% (systematic), in agreement with previous determinations. The cluster morphology and boundaries are established with great confidence, from the agreement between the subsamples of members selected using different criteria. There is no diffuse population of members around the cluster, but there are minor condensations of true members in addition to the two main groups in the cluster core and in the Hourglass nebula. Two such subgroups are spatially associated with the stars 7 Sgr (F2II-III) and HD 164536 (O7.5V). There is a definite pattern of sequential star formation across the cluster, within an age range from less than 0.5Myr to ~5Myr. Extinction is spatially non-uniform, with part of the population still embedded or obscured by thick dust. The precise Gaia proper motion data indicate that the NGC 6530 parent cloud collided with the Galactic plane around 4Myr ago, and we suggest that event as the trigger of the bulk of star formation in NGC 6530. The internal cluster dynamics is also partially resolved by the Gaia data, indicating expansion of the main cluster population with respect to its center.
Almost simultaneous measurements in the Geneva seven-colour photometric system and in radial velocities with the spectrometer CORAVEL for five RR Lyrae field stars were obtained in order to apply the Baade-Wesselink method to this kind of variable stars. In this paper the observational data on these stars are presented; the analysis of their physical parameters will be published in the forthcoming paper of the series.
Photometric and Spectroscopic Databases for LSS Stars
Short Name:
V/92A
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalog contains databases of published photoelectric UBVbeta data, MK-system spectral classifications, and Stroemgren four-color uvby photometry for objects in the Stephenson-Sanduleak "Luminous Stars in the Southern Milky Way" catalog (LSS catalog). The catalog contains mostly OB stars and A and F supergiants. These databases have been compiled from the literature.