- ID:
- ivo://CDS.VizieR/J/MNRAS/466/392
- Title:
- UBVRICT1T2 photometry of 7 open clusters
- Short Name:
- J/MNRAS/466/392
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive UBVRI and Washington CT_1_T_2_ photometric analysis of seven catalogued open clusters, namely: Ruprecht 3, 9, 37, 74, 150, ESO 324-15 and 436-2. The multiband photometric data sets in combination with 2MASS photometry and Gaia astrometry for the brighter stars were used to estimate their structural parameters and fundamental astrophysical properties. We found that Ruprecht 3 and ESO 436-2 do not show self-consistent evidence of being physical systems. The remained studied objects are open clusters of intermediate age (9.0<=log(t[yr^-1^])<=9.6), of relatively small size (r_cls_~0.4-1.3pc) and placed between 0.6 and 2.9kpc from the Sun. We analysed the relationships between core, half-mass, tidal and Jacoby radii as well as half-mass relaxation times to conclude that the studied clusters are in an evolved dynamical stage. The total cluster masses obtained by summing those of the observed cluster stars resulted to be ~10-15 per cent of the masses of open clusters of similar age located closer than 2kpc from the Sun. We found that cluster stars occupy volumes as large as those for tidally filled clusters.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/441/905
- Title:
- UBVRI from the Garching-Bonn Deep Survey
- Short Name:
- J/A+A/441/905
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present first results of our search for high-redshift galaxies in deep CCD mosaic images. As a pilot study for a larger survey, very deep images of the Chandra Deep Field South (CDFS), taken with WFI@MPG/ESO2.2m, are used to select large samples of 1070 U-band and 565 B-band dropouts with the Lyman-break method.
- ID:
- ivo://CDS.VizieR/J/A+A/511/A25
- Title:
- UBVRIH{alpha} photometry of NGC6383
- Short Name:
- J/A+A/511/A25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The very young open cluster NGC 6383 centered on the O-star binary HD 159176 is an interesting place for studying the impact of early-type stars with strong radiation fields and powerful winds on the formation processes of low-mass stars. To investigate this process, it is necessary to determine the characteristics (age, presence, or absence of circumstellar material) of the population of low-mass pre-main-sequence (PMS) stars in the cluster. We obtained deep U B V Rc Ic H{alpha} photometric data of the entire cluster as well as medium-resolution optical spectroscopy of a subsample of X-ray selected objects. Our spectroscopic data reveal only very weak H{alpha} emission lines in a few X-ray selected PMS candidates. We photometrically identify a number of H-{alpha} emission candidates but their cluster membership is uncertain. We find that the fainter objects in the field of view have a wide range of extinction (up to A_V_=20), one X-ray selected OB star having A_V_~8. Our investigation uncovers a population of PMS stars in NGC 6383 that are probably coeval with HD 159176. In addition, we detect a population of reddened objects that are probably located at different depths within the natal molecular cloud of the cluster. Finally, we identify a rather complex spatial distribution of H{alpha} emitters, which is probably indicative of a severe contamination by foreground and background stars.
- ID:
- ivo://CDS.VizieR/J/A+A/402/549
- Title:
- UBVRIHalpha photometry of NGC 3293
- Short Name:
- J/A+A/402/549
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Deep and extensive CCD photometric observations at UBV(RI)cH{alpha} were carried out in the area of the open cluster NGC 3293. The new data set allows to see the entire cluster sequence down to Mv~+4.5, revealing that stars with Mv<-2 are evolving off the main sequence; stars with -2<Mv<+2 are located on the main sequence and stars with Mv>+2 are placed above it. According to our analysis, the cluster distance is d=2750+/-250pc (V0-Mv=12.2+/-0.2) and its nuclear age is 8+/-1Myr. NGC 3293 contains an important fraction of pre-main sequence (PMS) stars distributed along a parallel band to the ZAMS with masses from 1 to 2.5M_{sun}_ and a mean contraction age of 10Myr. This last value does not differ too much from the nuclear age estimate. If we take into account the many factors that may affect the PMS star positions on the colour-magnitude diagram, both ages can be perfectly reconciled. The star formation rate, on the other hand, suggests that NGC 3293 stars formed surely in one single event, therefore favouring a coeval process of star formation. Using the Halpha data, we detected nineteen stars with signs of Halpha emission in the region of NGC 3293, another indication that the star formation process is still active in the region. The computed initial mass function for the cluster has a slope of x=1.2+/-0.2, a bit flatter than the typical slope for field stars and similar to the values found for other young open clusters.
- ID:
- ivo://CDS.VizieR/J/AJ/114/2644
- Title:
- UBVRIHa photometry of NGC2264
- Short Name:
- J/AJ/114/2644
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- UBVRI H{alpha} CCD photometry has been obtained fro the young cluster NGC 2264. Using (R-H{alpha}) color, a measure of H{alpha} emission, we selected member stars in the pre-main sequence (PMS) stage.
- ID:
- ivo://CDS.VizieR/J/A+A/605/A99
- Title:
- UBVRI images of Barnard 207
- Short Name:
- J/A+A/605/A99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Barnard 207 (B207, LDN 1489, LBN 777), also known as the Vulture Head nebula, is a cometary globule in the Taurus-Auriga-Perseus Molecular Cloud region. B207 is known to host a Class I protostar, IRAS 04016+2610, located at a projected distance of ~8400au from the dense core centre. Using imaging and photometry over a wide wavelength range, from UV to sub-mm, we study the physical properties of B207 and the dust grains contained within. The core density, temperature, and mass are typical of other globules found in the Milky Way interstellar medium (ISM). The increase in the dust albedo with increasing optical wavelengths, along with the detection of coreshine in the near infrared, indicates the presence of larger dust grains in B207. The measured optical, near-, mid- and far-infrared intensities are in agreement with the CMM+AMM and CMM+AMMI dust grain type of the THEMIS model, suggesting mantle formation on the dust grains throughout the globule. We investigate the possibility of turbulence being responsible for diffusing dust grains from the central core to external outer layers of B207. However, in situ formation of large dust grains cannot be excluded.
- ID:
- ivo://CDS.VizieR/J/MNRAS/411/2530
- Title:
- UBVRIJHK photometry in NGC1624
- Short Name:
- J/MNRAS/411/2530
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive multiwavelength analysis of the young cluster NGC 1624 associated with the HII region Sh2-212 using optical UBVRI photometry, optical spectroscopy and GMRT radio continuum mapping along with the near-infrared (NIR) JHK archival data.
- ID:
- ivo://CDS.VizieR/J/AJ/122/2055
- Title:
- UBVRIJHK photometry of AGN field stars
- Short Name:
- J/AJ/122/2055
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a total of 12,436 photometric measures of 371 field stars of 26 quasars in the visible (UBVRI) and 22,276 photometric measures of 122 field stars of 13 quasars in the near-infrared (JHK), giving a total of 34,712 measures. Of these, 115 stars in 12 fields are calibrated in both ranges. One further field, Mrk 421, was calibrated, but on close examination all sources were found to be probably nonstellar; thus these results are not included here. The stars observed cover the range from V=11 to V=20 and from K=9 to K=17 and are well distributed around the sky north of declination -30{deg}. This represents the initial sample of an extensive catalog of calibrated fields that will cover the northern sky down to declination -30{deg} and that will cover a wide range of Galactic latitudes. These fields will be useful both for photometry of AGNs in the range from B to K and also as faint calibration standards for large telescopes. The median absolute total error on the photometry, including all known error sources, ranges from 0.008mag in J to 0.034mag in B. These errors will be greatly reduced with the addition of further data in the future, although the final precision is fundamentally limited by the photometric errors in the existing lists of calibration stars used to calibrate these data.
- ID:
- ivo://CDS.VizieR/J/A+A/509/A104
- Title:
- UBVRIJHK photometry of Dolidze 25
- Short Name:
- J/A+A/509/A104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The analysis of our deep UBVRIJHK photometry of Dolidze 25, located in the central area of the HII region Sh 2-284, reveals a young cluster with coeval MS and PMS populations of age 3.2-5Myr. The mass function for the optical PMS population in the mass range above 1.3-3.5M_{sun}_ is well fitted by a Salpeter mass function. On the other hand, the NIR photometry results indicate a large number of sources with H-Ks excess, practically distinct from the optical PMS candidate members. In addition, a distinctly older cluster member population of age 40Myr is suggested. The distance determined for the cluster from quantitative fits to ZAMS and isochrones (3.6kpc) is distinctly lower than previously published values. This result originates in the consistent use of low metallicity models for ZAMS fitting, applying published metallicity values for the cluster
- ID:
- ivo://CDS.VizieR/J/A+A/441/451
- Title:
- UBVRIJHK photometry of E-type galaxies
- Short Name:
- J/A+A/441/451
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Colour gradients are considered for a sample of circa 50 E-type galaxies in the Local Supercluster. The new data includes isophotal colour profiles in J-H, J-K, V-J and V-K, measured using 2MASS frames mostly from the Large Galaxies Atla s, V frames from previous work and V profiles from the literature. This is supplemented by U-B, B-V, B-R, V-I colour gradients obtained anew from published photometric data. The here available file gives our zero-point colours at r_e_/2 and the measured gradients for 54 objects, but for missing data.
