- ID:
- ivo://CDS.VizieR/J/AJ/144/41
- Title:
- UBVRI photometry of M33 star clusters. I.
- Short Name:
- J/AJ/144/41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present UBVRI photometry for 392 star clusters and candidates in the field of M33, which are selected from the most recent star cluster catalog. In this catalog, the authors listed star clusters' parameters such as cluster positions, magnitudes, colors in the UBVRIJHK_s_filters, and so on. However, a large fraction of objects in this catalog do not have previously published photometry. Photometry is performed using archival images from the Local Group Galaxies Survey, which covers 0.8deg^2^ along the major axis of M33. Detailed comparisons show that, in general, our photometry is consistent with previous measurements. Positions (right ascension and declination) for some clusters are corrected here. Combined with previous literature, ours constitute a large sample of M33 star clusters. Based on this cluster sample, we present some statistical results: none of the youngest M33 clusters (~10^7^yr) have masses approaching 10^5^M_{sun}_; roughly half the star clusters are consistent with the 10^4^-10^5^M_{sun}_ mass models; the continuous distribution of star clusters along the model line indicates that M33 star clusters have been formed continuously from the epoch of the first star cluster formation until recent times; and there are ~50 star clusters which are overlapped with the Galactic globular clusters on the color-color diagram, and these clusters are old globular cluster candidates in M33.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/145/88
- Title:
- UBVRI photometry of M33 star clusters. II.
- Short Name:
- J/AJ/145/88
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the second paper of our series. In this paper, we present UBVRI photometry for 234 star clusters in the field of M33. For most of these star clusters, there is photometry in only two bands in previous studies. The photometry of these star clusters is performed using archival images from the Local Group Galaxies Survey, which covers 0.8deg^2^ along the major axis of M33. Detailed comparisons show that, in general, our photometry is consistent with previous measurements, and in particular that our photometry is in good agreement with that of Zloczewski & Kaluzny. Combined with star cluster photometry in previous studies, we present some results: none of the M33 youngest clusters (~10^7^yr) have masses approaching 10^5^M_{sun}_, and comparisons with models of simple stellar populations suggest a large range of ages for M33 star clusters and some as old as the Galactic globular clusters.
14713. UBVRI photometry of NGC 2422
- ID:
- ivo://CDS.VizieR/J/A+A/404/927
- Title:
- UBVRI photometry of NGC 2422
- Short Name:
- J/A+A/404/927
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present UBVRI photometry of the open cluster NGC 2422 (age~10^8^yr) down to a limiting magnitude V=~19. These data are used to derive the Luminosity and Mass Functions and to study the cluster spatial distribution. By considering the color-magnitude diagram data and adopting a representative cluster main sequence, we obtained a list of candidate cluster members based on a photometric criterion.
- ID:
- ivo://CDS.VizieR/J/A+A/333/471
- Title:
- UBVRI photometry of NGC 1750 and NGC 1758
- Short Name:
- J/A+A/333/471
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The existence and relationship of the possible clusters NGC 1746, NGC 1750 and NGC 1758 has been a matter of discussion during the last decades. This star field is close to the galactic anticenter and lies in the direction of the Taurus dark cloud complex. As part of a comprehensive astrometric and photometric analysis of this zone, we present a brief historical introduction together with deep UBVRI-CCD photometry of the area. The presence of at least one cluster can be deduced from these data. This object has a position and apparent size compatible with those previously quoted for NGC 1750 and NGC 1758. It is not possible to distinguish the single or double nature of the cluster on the sole basis of our photometry and the spatial distribution of the stars. No photometric evidence was found for NGC 1746.
- ID:
- ivo://CDS.VizieR/J/MNRAS/437/804
- Title:
- UBVRI photometry of NGC559 stars
- Short Name:
- J/MNRAS/437/804
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present UBVRI photometry of stars in the field of the intermediate-age open cluster NGC 559. By determining the stellar membership probabilities derived through a photometric and kinematic study of the cluster, we identify the 22 most probable cluster members. These are used to obtain robust cluster parameters. The mean proper motion of the cluster is {mu}_x_=-3.29+/-0.35, {mu}_y_=-1.24+/-0.28mas/yr. The radial distribution of the stellar surface density gives a cluster radius of 4.5+/-0.2arcmin (3.2+/-0.2pc). By fitting solar metallicity stellar isochrones to the colour-colour and colour-magnitude diagrams, we find a uniform cluster reddening of E(B-V)=0.82+/-0.02. The cluster has an age of 224+/-25Myr and is at a distance of 2.43+/-0.23kpc. From the optical and near-infrared two-colour diagrams, we obtain colour excesses in the direction of the cluster E(V-K)=2.14+/-0.02, E(J-K)=0.37+/-0.01 and E(B-V)=0.76+/-0.04. A total-to-selective extinction of R_V_=3.5+/-0.1 is found in the direction of the cluster which is marginally higher than the normal value. We derive the luminosity function and the mass function for the cluster main sequence. The mass function slope is found to be -2.12+/-0.31. We find evidence of mass segregation in this dynamically relaxed cluster.
- ID:
- ivo://CDS.VizieR/J/AJ/98/1693
- Title:
- UBVRI photometry of NLTT stars
- Short Name:
- J/AJ/98/1693
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- UBVRI photometry is presented for a sample of 1656 southern stars, including 1211, that were previously not measured, drawn from the NLTT (Luyten, 1979; catalogue I/98) proper-motion catalog; the catalog is shown to be a rich source of subdwarfs. The normalized UV excess, d(U-B)0.6, photometric parallax, and interstellar reddening are calculated for each star when possible. Residuals between the photometry and the magnitudes published in the NLTT catalog indicate that the latter have a large scatter (~0.6mag) and therefore the values tabulated in the NLTT catalog must be regarded as approximate only. The erratum (Astron. J. 99, 1336) which deals with position angles of proper motions (pmPA) has been taken into account.
- ID:
- ivo://CDS.VizieR/J/AJ/129/2701
- Title:
- UBVRI photometry of SMC star clusters
- Short Name:
- J/AJ/129/2701
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present age measurements for 195 star clusters in the Small Magellanic Cloud based on comparison of integrated colors measured from the Magellanic Clouds Photometric Survey with models of simple stellar populations.
- ID:
- ivo://CDS.VizieR/J/A+AS/119/221
- Title:
- UBVRI photometry of stars in Berkeley 86
- Short Name:
- J/A+AS/119/221
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Based on photometry of deep CCD frames of the central region of the OB cluster Berkeley 86, we derive the cluster mass function. The absence of current star formation, and the cluster's young age of about 6Myrs, leads to the conclusion that the initial mass function (IMF) and the current mass function are identical for stars with m<10m_{sun}_. In the range of 1.2-20m_{sun}_, an IMF with a slope of {GAMMA}=-1.3+/-0.3 is found. This value agrees well with other recent determinations of young clusters IMFs which are close to the classical Salpeter IMF with {GAMMA}=-1.35. Sections of the IMF of Berkeley 86 that are significantly steeper, or flatter, are most likely the result of a dip in the star's mass distribution in the range of 3.5-10m_{sun}_. Similar dips may have led to steep IMFs over narrow mass ranges, as reported in the literature for some other clusters. No sign for a low mass turn-over in the IMF of Berkeley 86 is found for masses extending down to 0.85 m_{sun}_.
- ID:
- ivo://CDS.VizieR/J/ApJ/764/172
- Title:
- UBVRI photometry of stars toward NGC 1931
- Short Name:
- J/ApJ/764/172
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical photometric and polarimetric observations of stars toward NGC 1931 with the aim of deriving cluster parameters such as distance, reddening, age, and luminosity/mass function as well as understanding dust properties and star formation in the region. The distance to the cluster is found to be 2.3+/-0.3kpc and the reddening E(B-V) in the region is found to be variable. The stellar density contours reveal two clusters in the region. The observations suggest a differing reddening law within the cluster region. Polarization efficiency of the dust grains toward the direction of the cluster is found to be less than that for the general diffuse interstellar medium (ISM). The slope of the mass function (-0.98+/-0.22) in the southern region in the mass range of 0.8<M/M_{sun}_<9.8 is found to be shallower in comparison to that in the northern region (-1.26+/-0.23), which is comparable to the Salpeter value (-1.35). The K-band luminosity function (KLF) of the region is found to be comparable to the average value of the slope (~0.4) for young clusters obtained by Lada & Lada (2003ARA&A..41...57L); however, the slope of the KLF is steeper in the northern region as compared to the southern region. The region is probably ionized by two B2 main-sequence-type stars. The mean age of the young stellar objects (YSOs) is found to be 2+/-1Myr, which suggests that the identified YSOs could be younger than the ionizing sources of the region. The morphology of the region, the distribution and ages of the YSOs, and ionizing sources indicate a triggered star formation in the region.
14720. UBVRI photometry of Stock 18
- ID:
- ivo://CDS.VizieR/J/other/NewA/17.160
- Title:
- UBVRI photometry of Stock 18
- Short Name:
- J/other/NewA/17.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out deep (V~21mag) UBVRI photometric study of the star cluster Stock 18. These along with archival Infrared data have been used to derive the basic cluster parameters and also to derive the basic cluster parameters and also to study the star for formation processes in and around the cluster region. The distance to the cluster is derived as 2.8+/-0.2kpc while its age is estimated as 6.0+/-2.0Myr. Present study indicates that interstellar reddening is normal in the direction of the cluster. The mass function slope is found to be -1.37+/-0.27 for the mass range 1<M/M_{sun}_<11.9. There is no evidence found for the effect of mass segregation in main-sequence stars of the cluster. A young stellar population with age between 1-2Myr have been found in and around the cluster region. The presence of IRAS and AKARI sources with MSX intensity map also show the youth of the Sh2-170 region.
