- ID:
- ivo://CDS.VizieR/J/A+A/448/171
- Title:
- BV photometry of 3 globular clusters
- Short Name:
- J/A+A/448/171
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Some of the Galactic outer halo globular clusters are excellent tools to probe gravitational theories in the regime of weak accelerations. The measurement of the line-of-sight velocity dispersion among stars in these clusters will differentiate between the validity of Newtonian dynamics (low velocity dispersion) and the possibility of modified Newtonian dynamics (MOND) or dark matter dominated globular clusters (high velocity dispersion). In this paper, the properties of probable member stars of the three best-case gravitational theory-testing clusters AM 1, Pal 3 and Pal 14 are presented. The member selection is based on VLT photometry in Johnson BV. The positions of the stars were determined with an accuracy of the order of <=0.2", allowing their direct use for follow-up spectroscopy. The distance, reddening, age and metallicities of the clusters were estimated from isochrone fitting. Furthermore, improved structural parameters, like central coordinates, ellipticity, half-light radius, King model core and tidal radius, are presented.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/129/1669
- Title:
- BV photometry of HD 37824, HD 181809, and HD 217188
- Short Name:
- J/AJ/129/1669
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained spectroscopy and photometry of three chromospherically active, single-lined spectroscopic binaries: HD 37824 (V1149 Ori), HD 181809 (V4138 Sgr), and HD 217188 (AZ Psc). * HD 37824 has a circular orbit with a period of 53.57 days. Its primary is a K0 III star, while the secondary is likely a G or K dwarf. * HD 181809 has an orbit with a period of 13.04667 days and a low eccentricity of 0.040. The primary has a spectral type of K0 IIIIV, and its secondary is probably an M dwarf. * The orbit of HD 217188 has a period of 47.1209 days and a moderately high eccentricity of 0.470. The spectral type of the primary is K0III, while the secondary is likely an M dwarf. All three systems are estimated to have near solar iron abundances. Photometric observations spanning 15-16 years for all three stars yield mean photometric periods of 53.12, 59.85, and 90.89 days for HD 37824, HD 181809, and HD 217188, respectively.
- ID:
- ivo://CDS.VizieR/J/AJ/126/237
- Title:
- BV photometry of LW 55 in LMC
- Short Name:
- J/AJ/126/237
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The field of the moderately old open cluster LW 55 in the outer parts of the Large Magellanic Cloud disk was monitored for detection of short-period variable stars over two nights. Eight variables were found; all but one (a detached eclipsing binary) are small-amplitude ({Delta}V<=0.1mag) pulsating stars of the {delta} Scuti, SX Phoenicis, or Doradus type. The BV color-magnitude diagram extends down to the solar-type stars at V=24 (M_V_~5.2). The cluster age is estimated at 1.5Gyr for Z=0.004 ([Fe/H]=-0.67); the surrounding stellar field is older, with an age greater than 4Gyr.
204. BV photometry of M71
- ID:
- ivo://CDS.VizieR/J/A+AS/144/227
- Title:
- BV photometry of M71
- Short Name:
- J/A+AS/144/227
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- File table2 contains coordinates (J2000) and B,V magnitudes and B-V colours with corresponding errors of 4450 stars in a 20'x20' region centered on the globular cluster M 71 (NGC 6838). The limiting magnitude of the catalogue is about V=18.0 The observations were made in 1995 at Calar Alta Observatory.
- ID:
- ivo://CDS.VizieR/J/A+A/459/321
- Title:
- BV photometry of M31 eclipsing binaries
- Short Name:
- J/A+A/459/321
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Broad band photometry (in Johnson B and V) has been obtained in a region (34'x34') at the North-Eastern quadrant of M31 over 5 years (1999-2003) at the Isaac Newton Telescope (La Palma, Spain). The data, containing more than 250 observations per filter, have been reduced by means of the so-called difference image analysis technique and the DAOPHOT program. A catalog with 236238 objects with photometry in both B and V passbands has been obtained. The catalog is the deepest (V<25.5mag) obtained so far in the studied region and contains 3964 identified variable stars, with 437 eclipsing binaries and 416 Cepheids.
- ID:
- ivo://CDS.VizieR/J/PASP/119/1233
- Title:
- BV photometry of M11 stars
- Short Name:
- J/PASP/119/1233
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- V-band time-series CCD photometric observations of the intermediate-age open cluster M11 were performed to search for variable stars.
- ID:
- ivo://CDS.VizieR/J/AJ/118/2839
- Title:
- BV photometry of NGC 1866
- Short Name:
- J/AJ/118/2839
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new deep (down to V~24) photometry of a wide region (~6'x6') around the Large Magellanic Cloud globular cluster NGC 1866. Our sample is much larger (by more than a factor of 3) than any previous photometry and with a main sequence (MS) that may be considered complete, down to at least 3 mag below the brightest MS star; such an occurrence allows a meaningful and robust comparison with various theoretical scenarios produced by means of models computed with the evolutionary code FRANEC.
- ID:
- ivo://CDS.VizieR/J/A+A/431/1189
- Title:
- BV photometry of NGC 6822 variables
- Short Name:
- J/A+A/431/1189
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Deep B, V time-series photometry obtained with the ESO Very Large Telescope has been used to identify variable stars in the dwarf irregular galaxy NGC 6822. We surveyed a 6.8x6.8 arcmin area of the galaxy and detected a total number of 390 candidate variables with the optimal image subtraction technique (Alard C., 2000A&AS..144..363A). Light curves on a magnitude scale were obtained for 262 of these variables. Differential flux light curve are available for the remaining sample. We were able to determine periods and pulsation characteristics for 69 out of the 262 variables with light curves in magnitude scale, they include: 18 RR Lyrae stars (16 ab-type and 2 c-type), 45 Cepheids and 6 binary systems. We also tentatively calibrated 8 of the 128 objects with light curves on a differential flux scale on the assumption that they are ab-type RR Lyrae stars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/350/679
- Title:
- BV photometry of NGC 300 variables
- Short Name:
- J/MNRAS/350/679
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have performed a search for variable stars in the Sculptor Group spiral galaxy NGC 300 using wide-field multi-epoch BV photometry up to a limiting magnitude V~23. Apart from the Cepheid variables in this galaxy already reported in an earlier paper by Pietrzynski et al. (2002, Cat. <J/AJ/123/789>) and the variable blue supergiants reported by Bresolin et al. (2002ApJ...567..277B), we have identified 26 additional periodic variables, with periods ranging from 0.2 to 190d, and 121 slow variables. Two of these newly discovered variables are Galactic foreground stars (one of them is a W UMa system), and three correspond to previously identified Wolf-Rayet stars. 16 stars are new Cepheids, and the other objects span a huge range in colours and represent a mixture of different types of luminous variables.
- ID:
- ivo://CDS.VizieR/J/A+A/483/253
- Title:
- BV photometry of NGC 2099 variables
- Short Name:
- J/A+A/483/253
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Rotation and solar-type magnetic activity are closely related to each other in main-sequence stars of G or later spectral types. The presence and level of magnetic activity depend on star's rotation, and rotation itself is strongly influenced by strength and topology of the magnetic fields. Open clusters represent especially useful targets to investigate the connection between rotation and activity. The open cluster NGC 2099 has been studied as a part of the RACE-OC project (Rotation and ACtivity Evolution in Open Clusters), which is aimed at exploring the evolution of rotation and magnetic activity in the late-type members of open clusters of different ages. We collected time series CCD photometric observations of this cluster in January 2004, and we determined the presence of periodicities in the flux variation related to the stellar rotation by Fourier analysis. We investigate the relations between activity manifestations, such as the light curve amplitude, and global stellar parameters. We have discovered 135 periodic variables, 122 of which are candidate cluster members. Determination of rotation periods of G- and K-type stars has allowed us to better explore the evolution of angular momentum at an age of about 500Myr. In our analysis, we have also identified 3 new detached eclipsing binary candidates among cluster members. A comparison with the older Hyades cluster (~625Myr) shows that the newly-determined distribution of rotation periods is consistent with the scenario of rotational braking of main-sequence spotted stars as they age. However, a comparison with the younger M34 cluster (~200Myr) shows that the G8-K5 members of these clusters have the same rotation period distribution. That is, G8-K5 members in NGC 2099 seem to have experienced no significant braking in the age range from ~200 to ~500Myr. Finally, NGC 2099 members have a smaller level of photospheric magnetic activity, as measured by light curve amplitude, than in younger stars of the same mass and rotation, suggesting that the activity level also depends on some other age-dependent parameters.
