- 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.
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- 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/MNRAS/372/1315
- Title:
- UBVRI photometry of SN 2004et
- Short Name:
- J/MNRAS/372/1315
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical photometry and spectroscopy of the Type IIP supernova SN 2004et that occurred in the nearby galaxy NGC 6946. The observations span a time range of 8541 d after explosion. The late time bolometric luminosity and the H{alpha} luminosity in the nebular phase indicate that 0.06+/-0.02M_{sun}_ of ^56^Ni was synthesized during the explosion. The plateau luminosity, its duration and the expansion velocity of the supernova at the middle of the plateau indicate an explosion energy of E_exp_=1.20^+0.38^_-0.30_x10^51^erg. The late time light curve and the evolution of the [OI] and H{alpha} emission-line profiles indicate the possibility of an early dust formation in the supernova ejecta. The luminosity of [OI] 6300, 6364{AA} doublet, before the dust formation phase, is found to be comparable to that of SN 1987A at similar epochs, implying an oxygen mass in the range 1.52M_{sun}_, and a main-sequence mass of 20M_{sun}_ for the progenitor.
- ID:
- ivo://CDS.VizieR/J/A+AS/128/561
- Title:
- UBVRI photometry of southern T Tauri stars
- Short Name:
- J/A+AS/128/561
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present full tables of the photoelectric photometry of T Tauri Stars observed in the 0.5m telescope at Laboratorio Nacional de Astronomia (Brazil). The photometry was performed with the instrument FOTRAP (Jablonski et al., 1994PASP..106.1172J, see text). For a description of the UBVRI photometric system, see e.g. <GCPD/08>
- 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.
- 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.
- ID:
- ivo://CDS.VizieR/J/MNRAS/339/44
- Title:
- UBVRI photometry of Tr 14, Tr 15 and Tr 16
- Short Name:
- J/MNRAS/339/44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a large-scale imaging photometric study of the stellar population in the northern part of NGC 3372 in the UBVRIJHK bands with a wavelength coverage from 0.33 to 2.5{mu}m. The observations were made at Las Campanas Observatory. The optical CCD mosaics cover an area approximately of 32x22arcmin^2^ centred between the Tr 14 and Tr 16 clusters. The survey was extended to cover 12x12arcmin^2^ at the location of Tr 15. Near-infrared NICMOS3 mosaics covering the areas occupied by these clusters were obtained in the JHK photometric bands. By means of star counts in V, the centres and sizes of each cluster were redetermined yielding: Tr 14 (r=264"), Tr 15 (r=320") and Tr 16 (r=320"). It was confirmed that Cr 232 is not a true cluster. Multicolour optical photometry was obtained for 4152 stars. Two colour and colour-magnitude diagrams are presented and analysed for each individual cluster and compared to those of the field. We confirm the widespread variations in the dust density and also in the dust size distribution leading to widely different values of A_V_and reddening laws towards Tr 14 and Tr 16. No spatial patterns were found for these variations. Spectroscopic parallaxes were computed and the results are consistent with all three clusters being at a similar distance from the Sun (<d>=2.7kpc) but the data have shown very large scatter in both A_V_and d. Analyses of the extinction-corrected colour-magnitude diagrams suggest ages between 3 and 60 million years for the stars in Tr 15 and between less than 1 and 6 million years for Tr 14 and Tr 16. A small number of infrared-excess stars were found in Tr 16 and Tr 14 but not in Tr 15. The distribution of stars in Tr 14 seen in the near-infrared suggests that this cluster is partially embedded in a molecular cloud. This molecular cloud extends towards the west reaching its highest density, marked by a CO peak emission, some three arcmin to the south-west of the nucleus of Tr 14. The rich ultraviolet field created by the Tr 14 stars ionizes most of the visible HII region in its vicinity and most of the radio HII region Car I. Evidence is found of ionization fronts leading into the molecular cloud, which appears to be "wrapping" the Tr 14 cluster. Deep JHK images of the Car I region reveal the presence of an embedded stellar population illuminating a large infrared reflection nebula. It includes at least one O9-B0 star associated with an ultracompact HII region. Nebulous 2.2{mu}m emission from three of the mid-infrared sources in the Tr 14 region is also found.
- ID:
- ivo://CDS.VizieR/J/PAZh/26/525
- Title:
- UBVRI photometry of V1016 Ori
- Short Name:
- J/PAZh/26/525
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New photoelectric UBVRI observations of the eclipsing variable V1016 Ori have been obtained with the AZT-11 telescope at Crimean Astrophysical Observatory and with the Zeiss-600 telescope at Mount Maidanak Observatory. Light curves are constructed from the new observations and from published and archival data. The table contains all used data.
- ID:
- ivo://CDS.VizieR/J/A+A/379/136
- Title:
- UBVRI photometry of 3 young open clusters
- Short Name:
- J/A+A/379/136
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we present and analyze CCD UBVRI photometry in the region of the three young open clusters NGC 3114, Collinder 228, and vdB-Hagen 99, located in the Carina spiral feature. NGC 3114 lies in the outskirts of the Carina nebula. We found 7 star members in a severely contaminated field, and obtain a distance of 950pc and an age less than 3x10^8^yrs. Collinder 228 is a younger cluster (8x10^6^yrs), located in front of the Carina nebula complex, for which we identify 11 new members and suggest that 30% of the stars are probably binaries. As for vdB-Hagen 99, we add 4 new members, confirming that it is a nearby cluster located at 500pc from the Sun and projected toward the direction of the Carina spiral arm. Observations were conducted at La Silla on April 13-16, 1996, with the 0.92m ESO-Dutch telescope.
