- ID:
- ivo://CDS.VizieR/J/ApJS/90/83
- Title:
- Binaries in NGC 3201
- Short Name:
- J/ApJS/90/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present BV CCD and APM photometry, accurate astrometry and 1859 radial velocities for 1318 stars within ~36deg of the Galactic globular cluster NGC 3201. The field and cluster populations separate unambiguously in two distinct samples since the systemic radial velocity of NGC 3201 is 494.2km/s. After removal of the 19 known NGC 3201 photometric variables in our sample, we have a database of 930 radial velocities for 420 member giants (276 of which have multiple velocity measurements) with which to identify spectroscopic binaries on the basis of radial velocity variations. The mean time span of the observations is 1.7yr, with coverage up to ~6yr for our best-studied stars. Monte Carlo simulations of the observed velocity variations have provided _upper_limits_ to the cluster binary fraction (for binaries with 0.1<=P<=5-10yr and mass ratios in the range 0.1-1) of 0.06-0.10 (circular orbits) and 0.15-0.18 (eccentric orbits). These results suggest an incidence of binarism for NGC 3201 consistent with the corresponding incidence among nearby solar-type stars having similar periods and mass ratios (0.04-0.08) and that for a small sample of other globular clusters (0.05-0.12) studied by Hut et al. (1992PASP..104..981H). The detailed analysis of the cluster dynamics, based on the data given here, are presented by Cote et al. (1995ApJ...454..788C).
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/131/912
- Title:
- BR photometry of Fornax dSph center
- Short Name:
- J/AJ/131/912
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have imaged the recently discovered stellar overdensity located approximately one core radius from the center of the Fornax dwarf spheroidal galaxy using the Magellan Clay 6.5m telescope with the Magellan Instant Camera. Superb seeing conditions allowed us to probe the stellar populations of this overdensity and of a control field within Fornax to a limiting magnitude of R=26. The color-magnitude diagram of the overdensity field is virtually identical to that of the control field, with the exception of the presence of a population arising from a very short (less than 300Myr in duration) burst of star formation 1.4Gyr ago.
- ID:
- ivo://CDS.VizieR/J/A+A/433/751
- Title:
- BR photometry of nearby Southern dwarf galaxies
- Short Name:
- J/A+A/433/751
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We carried out CCD photometry in the Johnson-Cousins B and R bands of 23 dwarf galaxies: SDIG, ESO 410-17, KK11, ESO 245-05, KKs3, KK27, KK38, KK40, IC 4662, KK244, KK246, KK247, KK248, KK249, KK253, KK255, KK256, KK257, KK258, KK259, UGCA 438, ESO 347-17, and UGCA 442. Both isolated galaxies and members of the Sculptor group and the NGC 1313 group were observed. The galaxy sample is characterized by a median distance of 9.3Mpc, and median absolute magnitude of -14.8mag. The central surface brightnesses are in the range from 22.2 to 24.4mag/arcsec^2^ in B.
- ID:
- ivo://CDS.VizieR/J/A+A/356/L21
- Title:
- BR photometry of ON 231
- Short Name:
- J/A+A/356/L21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present R- and B-band CCD observations of ON 231 that were made at the Dark Sky Observatory at Appalachian State University (DSO-data) during 37 nights in April 1998 - December 1999. The observations have been obtained in connection with current microvariability studies but this paper presents only the nightly averaged R and B magnitudes together with other details of these observations. These data were used to verify the 1395-day period proposed from the analysis of the prior data (all B-band data available in the 1971-1997 time interval). To transform R-band observations to B we used the equation: B=1.107*R-0.653.
- ID:
- ivo://CDS.VizieR/J/A+AS/134/317
- Title:
- BR photometry of UGC 685
- Short Name:
- J/A+AS/134/317
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- B and R CCD images and J NICMOS3 frames taken with the Calar Alto 3.5m telescope of the dwarf irregular galaxy UGC 685 are presented. The brightest part of the stellar population is resolved in B and R, very few also in J. The stellar color-magnitude diagram is discussed. An estimate of the distance to UGC 685 of 5. 5Mpc is derived based on the brightest blue supergiant stars. Most of the resolved bright stars show colors in the range -0.1<=B-R<=+0.7.
- ID:
- ivo://CDS.VizieR/J/AJ/136/594
- Title:
- BS Cas BVR light curves
- Short Name:
- J/AJ/136/594
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multicolor charge-coupled device (CCD) photometry for the eclipsing binary BS Cassiopeiae, observed on four nights between 2007 December and 2008 January. Using the Wilson-Devinney program, the photometric solution was derived from our BVR observations. Photometric results indicated that BS Cas is a W-subtype binary, whose mass ratio and overcontact degree are q=0.2834(+/-0.0010) and f=31.6%(+/-1.1%), respectively. Light curves of BS Cas present a typical O'Connell effect, which may be attributed to dark spot activity of the primary component.
- ID:
- ivo://CDS.VizieR/J/MNRAS/340/1346
- Title:
- Bulge SC1 proper motions
- Short Name:
- J/MNRAS/340/1346
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report a measurement of the streaming motion of the stars in the Galactic bar with the red clump giants (RCGs) using the data of the Optical Gravitational Lensing Experiment II (OGLE-II). We measure the proper motion of 46961 stars and divide RCGs into bright and faint subsamples that on average will be closer to the near and far sides of the bar, respectively. We find that the far-side RCGs (4979 stars) have a proper motion of {Delta}<{mu}>~1.5+/-0.11mas/yr toward the negative longitudes relative to the near-side RCGs (3610 stars).
- ID:
- ivo://CDS.VizieR/J/A+A/357/471
- Title:
- BV and proper motions in NGC 1960 & NGC 2194
- Short Name:
- J/A+A/357/471
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CCD photometry and proper motion studies of the two open star clusters NGC 1960 (M 36) and NGC 2194. Fitting isochrones to the colour magnitude diagrams, for NGC 1960 we found an age of 16Myr and a distance of roughly 1300 pc and for NGC 2194 550Myr and 2900pc, respectively. We combined membership determination by proper motions and statistical field star subtraction to derive the initial mass function of the clusters and found slopes of -1.23+/-0.17 for NGC 1960 and -1.33+/-0.29 for NGC 2194. Compared to other IMF studies of the intermediate mass range, these values indicate shallow mass functions. These tables present the complete data of the photometry (Tables 2 and 3) and the proper motion studies (Tables 7 and 9) of the two clusters.
- ID:
- ivo://CDS.VizieR/J/A+AS/121/499
- Title:
- BV and rg photometry of Pal 13
- Short Name:
- J/A+AS/121/499
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new CCD photometry of the halo cluster Palomar 13 is used to construct a color-magnitude diagram in the Thuan-Gunn and the B, V photometric systems. The color-magnitude diagram of the cluster shows as already noted by Ortolani et al. (1985AJ.....90..473O) an extremely poor red horizontal branch and a very sparsely populated giant branch. Seven BSS candidates are identified in the field of Palomar 13. The age of the cluster determined by fitting with the isochrones of Proffitt & Vanden Berg (1991ApJS...77..473P) and Bergbusch & Vanden Berg (1992ApJS...81..163B) and by a differential comparison of the color-magnitude diagram with that of Pal 5 is 12+/-2Gyr.
- ID:
- ivo://CDS.VizieR/J/A+A/463/981
- Title:
- BV CCD photometry in Westerlund 2
- Short Name:
- J/A+A/463/981
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The properties of the early-type stars in the core of the Westerlund 2 cluster are examined in order to establish a link between the cluster and the very massive Wolf-Rayet binary WR20a as well as the H II complex RCW 49. Photometric monitoring as well as spectroscopic observations of Westerlund 2 are used to search for light variability and to establish the spectral types of the early-type stars in the cluster core. The first light curves of the eclipsing binary WR 20a in B and V filters are analysed and a distance of 8kpc is inferred. Three additional eclipsing binaries, which are probable late O or early B-type cluster members, are discovered, but none of the known early O-type stars in the cluster displays significant photometric variability above 1% at the 1-sigma level. The twelve brightest O-type stars are found to have spectral types between O3 and O6.5, significantly earlier than previously thought. The distance of the early-type stars in Westerlund 2 is established to be in excellent agreement with the distance of WR20a, indicating that WR20a actually belongs to the cluster. Our best estimate of the cluster distance thus amounts to 8.0+/-1.4kpc. Despite the earlier spectral types, the currently known population of early-type stars in Westerlund 2 does not provide enough ionizing photons to account for the radio emission of the RCW 49 complex. This suggests that there might still exist a number of embedded early O-stars in RCW49.
