- ID:
- ivo://CDS.VizieR/J/MNRAS/341/805
- Title:
- UBVI CCD photometry of Cep OB3b
- Short Name:
- J/MNRAS/341/805
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of a low-mass pre-main-sequence (PMS) stellar population in the younger subgroup of the Cepheus OB3 association, Cep OB3b, using UBVI CCD photometry and follow-up spectroscopy. The optical survey covers approximately 1300arcmin^2^ on the sky and gives a global photometric and astrometric catalogue for more than 7000 objects. The location of a PMS population is well defined in a V versus (V-I) colour-magnitude diagram.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/310/982
- Title:
- UBVI CCD Photometry of M11 - II.
- Short Name:
- J/MNRAS/310/982
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This directory contains Johnson-Cousins UBVI photometric data for M11 (NGC 6705) and a neighboring field (around PN G027.4-03.5). The photometric data for M11 are tightly matched to the SAAO E-region standard system (Menzies et al. SAAO Circ., 1989SAAOC..13....1M; Menzies et al., 1991MNRAS.248..642M; Kilkenny et al., 1998MNRAS.294...93K). For the PN G027.4-03.5 region, the standard system of Landolt (1992, Cat. <II/183>) was used and small systematic difference in photometry between the two tables may be present, in particular in (U-B). Table 2 contains UBVI data for 14,179 stars brighter than V=17mag in M11 (about 40arcmin x 40arcmin region). The star numbers and proper motion memberships by McNamara et al. (1977A&AS...27..117M) and Su et al. (1998, Cat. <J/A+AS/128/255>) are also identified and included. Table 3 contains UBVI data for 3,676 stars around PN G027.4-03.5.
- ID:
- ivo://CDS.VizieR/J/MNRAS/306/361
- Title:
- UBVI CCD photometry of M35 (NGC 2168)
- Short Name:
- J/MNRAS/306/361
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- UBVI CCD photometry has been obtained for the intermediate-age open cluster M35 (NGC 2168). From this new photometry we derived the cluster parameters (Vo-MV= 9.60+/-0.10 mag, E(B-V) = 0.255+/-0.024 mag), age (logAge=8.3+/-0.3) and a photometric abundance (Z~0.008, i.e. [Fe/H]~-0.3) from comparison with theoretical isochrones of the Padova group. A minimum binary frequency (35+/-5%) was estimated from the distribution of distance moduli of unevolved proper motion members. Faint photometric members were selected by using differences in the reddening effect on colour indices.
- ID:
- ivo://CDS.VizieR/J/AJ/123/290
- Title:
- UBVI CCD photometry of NGC 2516
- Short Name:
- J/AJ/123/290
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present UBVI CCD photometry of the intermediate-age open cluster NGC 2516.
- ID:
- ivo://CDS.VizieR/J/AJ/145/46
- Title:
- UBVIc photometry in Westerlund 1
- Short Name:
- J/AJ/145/46
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Westerlund 1 is the most important starburst cluster in the Galaxy due to its massive star content. We have performed BVI_C_ and JK_S_ photometry to investigate the initial mass function (IMF). By comparing the observed color with the spectral-type-intrinsic-color relation, we obtain the mean interstellar reddening of <E(B-V)>=4.19+/-0.23 and <E(J-K_S_)>=1.70+/-0.21. Due to the heavy extinction toward the cluster, the zero-age main sequence fitting method based on optical photometry proved to be inappropriate for the distance determination, while the near-infrared photometry gave a reliable distance to the cluster, 3.8kpc from the empirical relation. Using the recent theoretical stellar evolution models with rotation, the age of the cluster is estimated to be 5.0+/-1.0Myr. We derived the IMF in the massive part and obtained a fairly shallow slope of {Gamma}=-0.8+/-0.1. The integration of the IMF gave a total mass for the cluster in excess of 5.0x10^4^M_{sun}_. The IMF shows a clear radial variation indicating the presence of mass segregation. We also discuss the possible star formation history of Westerlund 1 from the presence of red supergiants and relatively low luminosity yellow hypergiants.
- ID:
- ivo://CDS.VizieR/J/MNRAS/383/1241
- Title:
- UBVIc photometry of cluster Berkeley 59
- Short Name:
- J/MNRAS/383/1241
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present UBVIc CCD photometry of the young open cluster Be 59 with the aim to study the star formation scenario in the cluster. The radial extent of the cluster is found to be ~10arcmin (2.9pc). The interstellar extinction in the cluster region varies between E(B-V)=1.4 to 1.8mag. The ratio of total-to-selective extinction in the cluster region is estimated as 3.7+/-0.3. The distance of the cluster is found to be 1.00+/-0.05kpc. Using near-infrared (NIR) colours and slitless spectroscopy, we have identified young stellar objects (YSOs) in the open cluster Be 59 region. The Midcourse Space Experiment (MSX) and IRAS-HIRES images around the cluster region are also used to study the emission from unidentified infrared bands and to estimate the spatial distribution of optical depth of warm and cold interstellar dust.
- ID:
- ivo://CDS.VizieR/J/A+A/419/149
- Title:
- UBV(I)c photometry of NGC 6996
- Short Name:
- J/A+A/419/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present and discuss broad band CCD UBV(I)c photometry and low resolution spectroscopy for stars in the region of the open cluster NGC 6996, located in the North America Nebula. The new data allow us to tightly constrain the basic properties of this object. We revise the cluster size, which in the past has been significantly underestimated. The width of the Main Sequence is mainly interpreted in terms of differential reddening, and indeed the stars' color excess E(B-V) ranges from 0.43 to 0.65, implying the presence of a significant and evenly distributed dust component. We cross-correlate our optical photometry with near infrared photometry from 2MASS, and by means of spectral classification we are able to build extinction curves for an handful of bright members. We find that the reddening slope and the total to selective absorption ratio Rv toward NGC 6996 are anomalous. Moreover the reddening-corrected colors and magnitudes allow us to derive estimates for the cluster distance and age, which turn out to be 760+/-70pc (V0-MV=9.4+/-0.2) and ~350Myr, respectively. Based on our results, we suggest that NGC 6996 is located in front of the North America Nebula, and does not seem to have any apparent relationship with it.
- ID:
- ivo://CDS.VizieR/J/A+A/436/527
- Title:
- UBVIc photometry of NGC 4852
- Short Name:
- J/A+A/436/527
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present wide-field deep UBVIc photometry for the previously unstudied open cluster NGC 4852 down to a limiting magnitude Ic~24, obtained from observations taken with the Wide Field Imager camera on-board the MPG/ESO 2.2m telescope at La Silla (ESO, Chile), in the photometric night of July 7, 2002. These data are used to obtain the first estimate of the cluster basic parameters, to study the cluster spatial extension by means of star counts, and to derive the Luminosity (LF) and Mass Functions (MF). The cluster radius turns out to be 5.0+/-1.0arcmin. The cluster emerges clearly from the field down to V=20mag. At fainter magnitudes, it is completely confused with the general Galactic disk field. The stars inside this region define a young open cluster (200 million years old) 1.1kpc far from the Sun (m-M=11.60, E(B-V)=0.45). The Present Day Mass Functions (PDMF) from the V photometry is one of the most extended in mass obtained to date, and can be represented as a power-law with a slope alpha=2.3+/-0.3 and (the Salpeter MF in this notation has a slope alpha=2.35), in the mass range 3.2<=m/m_{sun}_<=0.6. Below this mass, the MF cannot be considered as representative of the cluster MF, as the cluster merges with the field and therefore the MF is the result of the combined effect of strong irregularities in the stellar background and interaction of the cluster with the dense Galactic field. The cluster total mass at the limiting magnitude results to be 2570+/-210M_{sun}_.
- ID:
- ivo://CDS.VizieR/J/AN/325/307
- Title:
- UBVIc photometry of NGC 3077 center
- Short Name:
- J/AN/325/307
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present UBVIc photometry of starlike objects in the central region of NGC 3077. The colour-colour and colour-magnitude diagrams of the objects are discussed. Many of the objects under consideration, starlike from the ground, are probably dense young star clusters (super star clusters, SSC). Ages spreading over ~4 to ~150Myr are estimated for most of these objects. Sakai and Madore (2001ApJ...555..280S) found enhanced star formation ~30-125Myr ago also in the halo of this galaxy; thus, high star forming activity has occurred within the entire galaxy (centre and halo) since ~130..150Myr. Having ended in the outer regions about 30Myr ago, it is going on near the centre with full vigour.
- ID:
- ivo://CDS.VizieR/J/A+A/548/A125
- Title:
- UBVI data of open cluster Trumpler 27
- Short Name:
- J/A+A/548/A125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The spiral structure of the Milky Way inside the solar circle is still poorly known because of the high density of the material that causes strong extinction towards the Galactic center. We present results of the first extensive and deep color-color diagram (CCD) photometric survey carried out in the field of the open cluster Trumpler 27, an object immersed in a region of extremely high visual absorption in the constellation of Sagittarius not far from the Galaxy center. The survey covers almost a quarter of square degree. We look for young stars clumps that might plausibly be associated with spiral structure. Wide-field UBVI photometry combined with infrared information allows us to reconstruct the distribution in the reddening and distance of young stars in the field using the CCD and color-magnitude diagrams (CMD).
