- ID:
- ivo://CDS.VizieR/J/A+A/388/149
- Title:
- CCD Vilnius photometry of M56
- Short Name:
- J/A+A/388/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD observations of field stars in an area north-east of the globular cluster M 56 were obtained in six bands of the Vilnius photometric system. The data sets cover a field of 9'x9.5'. An outline of the data pathway from observations to reduction via IRAF is outlined in this text. Photometry of 366 stars brighter than 18th V magnitude has been obtained and the analysis of the observational errors is discussed.
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- ID:
- ivo://CDS.VizieR/J/BaltA/5/1
- Title:
- Classification of Population II stars
- Short Name:
- J/BaltA/5/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The astrophysical parameters compiled from literature for 809 stars of different types, mainly Population II stars, are presented. The results of classification in the Vilnius photometric system for the same stars are given. For a description of the Vilnius photometric system, see e.g. <GCPD/21>
- ID:
- ivo://CDS.VizieR/II/130
- Title:
- 2-D Classification, Vilnius Photometry M56 Region
- Short Name:
- II/130
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalogue gives the seven-color photometry in the Vilnius system stars and two-dimensional classification of 752 stars. Photographically determined magnitudes obtained by COSMOS (MacGillivray and Stobie 1984) on the Schmidt plates were input into software described by Smriglio et al. (1986) as a method of automated two-dimensional stellar classification in the Vilnius seven-color intermediate band photometric system (Straizys and Zdanavicius 1970). A region of approximately two square degrees in Lyra centered on RA(1950) = 19h14.6min, DE(1950) = 30deg05' in the direction of the globular cluster M56 was studied and the two-dimensional classification of 752 stars in the magnitude range V = 11 to 15 mag was studied. The photometric system, the method of reduction, the classification procedure and errors were described by Smriglio et al. (1986). The number of stars for which all the six color indices in the Vilnius system are available is close to 3000, but the number of stars which have received two dimensional classification is 752. The success rate of classification appears to be high for stars brighter than V = 15.0 mag for which photometric accuracy is better than +-5%.
- ID:
- ivo://CDS.VizieR/J/BaltA/11/441
- Title:
- Extinction along Cam and Per border
- Short Name:
- J/BaltA/11/441
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Interstellar extinction in a ~100 sq. degree area at the Camelopardalis and Perseus border is investigated. The study is based on the results of photoelectric photometry of 455 stars in the seven-color Vilnius photometric system published earlier. The nearest 100 stars with Hipparcos parallaxes show that the extinction starts to grow at a distance of 110-150pc. At a distance of 1 kpc the extinction A_v_ is within 1.2 and 2.4mag. At larger distances the extinction determination is affected by the limiting magnitude effect. At distances >1.5kpc a number of O-B stars with the extinctions between 2 and 4mag are found.
- ID:
- ivo://CDS.VizieR/J/BaltA/11/231
- Title:
- Extinction in MBM12
- Short Name:
- J/BaltA/11/231
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photoelectric magnitudes and color indices in the Vilnius seven-color system for 152 stars are used to investigate the interstellar extinction in the area of the Aries molecular cloud MBM 12, coinciding with the L1454 and L1457 dust clouds. Spectral types, absolute magnitudes, color excesses, interstellar extinctions and distances of the stars are determined. The plot of interstellar extinction A_v_ versus distance shows that the dust cloud is situated at a distance of 325pc, at 180pc from the Galactic plane, and its true diameter is about 11pc. The interstellar extinction law in the area is found to be normal, typical for the diffuse dust. Ten peculiar or unresolved binary stars and some heavily reddened stars are detected.
- ID:
- ivo://CDS.VizieR/J/A+AS/119/37
- Title:
- EZ CMa UBV & VBLUW photometry
- Short Name:
- J/A+AS/119/37
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present and analyse photometric and spectroscopic observations of the WN5 star EZ Canis Majoris obtained over a period of 7 years. We discuss the changing light curve, the shift in phase of the maxima and point to flare type variability seen in one night. Small amplitude variations are reported in another night. We have investigated the change of the average visual magnitude over a time span of 18 years and found a tentative cyclic variation with a time scale of 2425d (6.6yr) with a range of ~0.07mag. This, of course, should be verified. If true, a precession phenomenon may offer an explanation. The trend of the maximum light amplitude of the 3.766d cycle is also investigated and it shows a saw-tooth character with a timescale of ~400d. A possible relation with the magnetic activity of the star is discussed. We conclude that the line emission variability can be caused by both a single star model with an ever-changing wind and a binary (WN+NS) model.
- ID:
- ivo://CDS.VizieR/J/A+A/623/A22
- Title:
- IC 4996 Vilnius phot. and Gaia DR2 astrometry
- Short Name:
- J/A+A/623/A22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The open cluster IC 4996 in Cygnus and its vicinity are investigated applying two-dimensional photometric classification of stars measured in the Vilnius seven-color photometric system. Cluster members are identified by applying distances based on the Gaia DR2 parallaxes and the point vector diagram of the Gaia DR2 proper motions. For some B-type stars, spectroscopic MK types are also obtained from the Asiago spectra and collected from the literature. New parameters of the cluster are derived. Th interstellar extinction A(v) covers a wide range of values, from 1.3 to 2.4mag, the mean value in the central part of the cluster is 1.8mag. The cluster distance is 1915+/-110pc, and its age is within 8-10Myr. The cluster exhibits a long sequence from early B to G stars, where stars cooler than B8 are in the pre-main-sequence stage. The plot of the extinction versus distance shows a steep rise of A(v) up to 1.6mag at 700-800pc, which is probably related to dust clouds at the edge of the Great Cygnus Rift. The next extinction rise by an additional 0.8 mag at d>=1.7kpc is probably related to the associations Cyg OB1 and Cyg OB3. The cluster IC 4996 does not belong to the Cyg OB1 association, which is located closer to the Sun, at 1682+/-116pc. It seems likely that the cluster and the surrounding O-B stars have a common origin with the nearby association Cyg OB3 since the Gaia data show that these stellar groups are located at a similar distance.
- ID:
- ivo://CDS.VizieR/J/BaltA/19/63
- Title:
- IC 361 Vilnius photometry
- Short Name:
- J/BaltA/19/63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD photometry in the eight-color Vilnius + I system for 7250 stars down to I=19.6mag has been obtained in the 20'x26' field of the open cluster IC361 in Camelopardalis. The catalog of 1420 stars down to V~18.5mag is presented. It contains the coordinates, V magnitudes, seven color indices, quantitative photometric spectral types, absolute magnitudes and distances. The interstellar extinction is found to be non-uniform across the field, with the values of A_V_ in the range 1.9 to 2.4mag. The distribution of distance moduli of individual stars shows that the cluster is located as far as, or just beyond, the Perseus spiral arm.
- ID:
- ivo://CDS.VizieR/J/AJ/159/95
- Title:
- IC 1369 Vilnius photometry and Gaia DR2 astrometry
- Short Name:
- J/AJ/159/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The open cluster IC1369, located in Cygnus close to the galactic equator at the 89.6{deg} longitude, and its vicinity are investigated by applying two-dimensional photometric classification of stars down to V=19mag measured in the Vilnius seven-color photometric system. Employing the Gaia DR2 coordinates, parallaxes, and proper motions, 143 cluster members are found having cluster membership probabilities >=0.75. The hottest stars of the evolved main sequence are of spectral class B9. Distances to the cluster, determined by two methods based on the Gaia parallaxes, are 3280 and 3370pc with an uncertainty of 400-500pc. Employing the physical HR diagram with the coordinates logL/L_{sun}_ versus logTeff and the Padova isochrones, the cluster age is found to be between 300 and 350Myr. Among the cluster members we identified six red giants of spectral classes G5-G8 and luminosities II-III, 17 Am stars, one Ap star, and one B5 blue straggler. The extinction shows a steep rise up to ~2.0mag at 300-700pc, caused by the extensions of the dust cloud LDN970 and the Great Cygnus Rift, and up to ~2.5mag at the edge of the Perseus arm at 3.0kpc. The extinction is almost constant between 0.9 and 2.5kpc from the Sun. The average extinction of the cluster members is 2.54mag. A systematic error of color excesses found in the Argonaut calculator results is discussed.
- ID:
- ivo://CDS.VizieR/II/197
- Title:
- ISM towards IC 348 and Per OB2
- Short Name:
- II/197
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The relationship between interstellar extinction and distance in the direction of dark clouds in the areas around the open cluster IC 348 and the association Per OB2 is determined using the results of photoelectric photometry of 189 stars in the Vilnius photometric system.
