- ID:
- ivo://CDS.VizieR/J/ApJ/682/135
- Title:
- CCD photometry of M60
- Short Name:
- J/ApJ/682/135
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a photometric study of the globular clusters (GCs) in the giant elliptical galaxy M60 in the Virgo Cluster, based on deep, relatively wide field Washington CT_1_ CCD images. The CMD reveals a significant population of GCs in M60 and a large number of young luminous clusters in NGC 4647, a small companion spiral northwest of M60. The color distribution of the GCs in M60 is clearly bimodal, with a blue peak at (C-T_1_)=1.37 and a red peak at (C-T_1_)=1.87. We derive two new transformation relations between the (C-T_1_)_0_ color and [Fe/H] using the data for the GCs in our Galaxy and M49. Using these relations, we derive the metallicity distribution of the GCs in M60, which is also bimodal: a dominant metal-poor component with center at [Fe/H]=-1.2, and a weaker metal-rich component with center at [Fe/H]=-0.2. We estimate the total number of the GCs in M60 to be 3600+/-500 and the specific frequency to be S_N_=3.8+/-0.4.
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Search Results
- ID:
- ivo://CDS.VizieR/J/other/RMxAA/39.39
- Title:
- CCD Photometry of NGC 2658, 2849, 3247
- Short Name:
- J/other/RMxAA/39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD photometry of the galactic open clusters NGC 2658, NGC 2849, and NGC 3247 is presented. For the first two clusters, BV(RI)_c data are given, and for NGC 3247 the data are BV(I)_c. The observations were carried out from the Complejo Astronomico El Leoncito (Argentina), and from Las Campanas (Chile). Each cluster was observed on two different nights; when possible, measurements for a given star were averaged. NGC 2658 observations were carried out from CASLEO on the nights of 8-9 January 1997 and 18-19 April 2001, in the BVRI filters. NGC 2849 data in the BVRI filters were obtained at Las Campanas on the night 10-11 April 1996, and at CASLEO on 19-20 April 2001. NGC 3247 was observed at CASLEO on the nights 16-17 January 1996 (BV) and 1-2 April 1998 (BVI). The given star coordinates are relative to the corresponding cluster center.
- ID:
- ivo://CDS.VizieR/J/AJ/106/181
- Title:
- CCD photometry of open cluster M67
- Short Name:
- J/AJ/106/181
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a CCD photometric survey of the central one-half degree of the old open cluster, M67, in U, B, V, and I colors to magnitude V=20. Extensive comparison of our photometry with other published datasets shows excellent agreement, indicating that CCD photometry is capable of producing a uniform set of measurements consistent with the photometric system defined primarily by the Landolt standard sequence. The color-magnitude diagram of the cluster shows a well-defined main sequence extending at least to the limit of the photometry at M(V)=10.55 and a substantial binary sequence. At least 38 percent of cluster stars are binaries. The observations were performed on 3 nights on 15-18 February 1990 with the 1.09m telescope at Kitt Peak National Observatory with a Tektronix 512^2^ CCD camera; a standard KPNO UBVRI filter set was used, with BVR filters being the Harris et, and I the "nearly Mould" filter.
- ID:
- ivo://CDS.VizieR/J/MNRAS/450/2122
- Title:
- CCD photometry of star clusters in the LMC
- Short Name:
- J/MNRAS/450/2122
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Washington system colour-magnitude diagrams (CMDs) for 17 practically unstudied star clusters located in the bar as well as in the inner disc and outer regions of the Large Magellanic Cloud (LMC). Cluster sizes were estimated from star counts distributed throughout the entire observed fields. Based on the best fits of theoretical isochrones to the cleaned (C-T_1_, T_1_) CMDs, as well as on the {delta}T_1_ parameter and the standard giant branch method, we derive ages and metallicities for the cluster sample. Four objects are found to be intermediate-age clusters (1.8-2.5 Gyr), with [Fe/H] ranging from -0.66 to -0.84. With the exception of SL 263, a very young cluster (~16 Myr), the remaining 12 objects are aged between 0.32 and 0.89 Gyr, with their [Fe/H] values ranging from -0.19 to -0.50. We combined our results with those for other 231 clusters studied in a similar way using the Washington system. The resulting age-metallicity relationship shows a significant dispersion in metallicities, whatever age is considered. Although there seems to exist a clear tendency for the younger clusters to be more metal rich than the intermediate ones, we believe that none of the chemical evolution models currently available in the literature reasonably well represents the recent chemical enrichment processes in the LMC clusters. The present sample of 17 clusters is part of our ongoing project of generating a data base of LMC clusters homogeneously studied using the Washington photometric system and applying the same analysis procedure.
- ID:
- ivo://CDS.VizieR/J/AJ/144/149
- Title:
- CCD photometry of the W UMa type TY Boo
- Short Name:
- J/AJ/144/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New CCD four-color light curves of TY Boo made on eight nights over 2010-2011 were analyzed in comparison with historical light curves obtained from 1969 through 2011. The light curves could all be represented by a unique geometry and by wavelength consistent photometric parameters of a two-spot model on either stellar component. It is confirmed that TY Boo is a shallow W-type contact binary system with a degree of contact factor of f=7.6%(+/-0.8). A period investigation based on all available data shows a long-term decrease (dP/dt=-3.65x10^-8^days/yr) and an oscillation (P_3_=58.9yr, A=0.0254days). Without ruling out the presence of a tertiary companion, the weight of evidence points to an active cyclic magnetic activity that causes spot formation rather than an unseen companion. Mass transfer between the components and angular momentum loss are also considered as possible mechanisms.
- ID:
- ivo://CDS.VizieR/J/AJ/143/30
- Title:
- CCD photometry of V380 Cas
- Short Name:
- J/AJ/143/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first multicolor CCD photometry for the eclipsing binary V380 Cassiopeia (V380 Cas) observed on 34 nights in 2009 and 2010 at the University of Patras Observatory. The PHOEBE program based on the Wilson-Devinney algorithm was used to analyze the first complete BVRcIc light curves. It was found that V380 Cas was misclassified and it is a well-detached system consisting of two main-sequence stars. A range of solutions found to give satisfactory fits to the observations is also investigated. The first orbital solution based on the photometric mass ratio q=1.08 of almost equal temperatures and masses and orbital inclination of i=86.57{deg} was obtained. In addition, based on all available times of light minima, including 12 new ones, a new orbital period of P=2.714539884 days is given.
- ID:
- ivo://CDS.VizieR/J/AJ/155/58
- Title:
- 2006-2016 CCD photometry of V723 Cassiopeia
- Short Name:
- J/AJ/155/58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometric data of the classical nova, V723 Cas (Nova Cas 1995), over a span of 10 years (2006 through 2016) taken with the 0.9 m telescope at Lowell Observatory, operated as the National Undergraduate Research Observatory (NURO) on Anderson Mesa near Flagstaff, Arizona. A photometric analysis of the data produced light curves in the optical bands (Bessel B, V, and R filters). The data analyzed here reveal an asymmetric light curve (steep rise to maximum, followed by a slow decline to minimum), the overall structure of which exhibits pronounced evolution including a decrease in magnitude from year to year, at the rate of ~0.15 mag/yr. We model these data with an irradiated secondary and an accretion disk with a hot spot using the eclipsing binary modeling program Nightfall. We find that we can model reasonably well each season of observation by changing very few parameters. The longitude of the hot spot on the disk and the brightness of the irradiated spot on the companion are largely responsible for the majority of the observed changes in the light curve shape and amplitude until 2009. After that, a decrease in the temperature of the white dwarf is required to model the observed light curves. This is supported by Swift/X-Ray Telescope observations, which indicate that nuclear fusion has ceased, and that V723 Cas is no longer detectable in the X-ray.
- ID:
- ivo://CDS.VizieR/J/A+AS/129/337
- Title:
- CCD photometry of YY Orionis stars
- Short Name:
- J/A+AS/129/337
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results of photometric monitoring in the UBVRI bands of 5 YY Orionis stars and 2 other variable stars are presented. Each source was observed in the period of 1996, Nov. 23 to Dec. 2 and of 1996, Dec. 23 to 1997,Jan. 2 at the 1-m telescope of Wise Observatory, Israel. Tables.dat contain the luminosity variation of each star as deviation from its average observed magnitude.
- ID:
- ivo://CDS.VizieR/J/A+A/376/745
- Title:
- CCD standards for U and I in NGC 7790
- Short Name:
- J/A+A/376/745
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometric U and I standard sequences in the field of the open cluster NGC 7790 are presented. The intention is to achieve wide ranges in magnitude and colour, making these sequences suitable for calibrating deep CCD photometry. The 84 standard stars extend the BVR sequences of Odewahn et al. (1992PASP..104..553O) to the near UV and IR, respectively.
- ID:
- ivo://CDS.VizieR/J/A+A/432/491
- Title:
- CCD UBVIc photometry of Pismis 8 and Pismis 13
- Short Name:
- J/A+A/432/491
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD UBVIc imaging photometry was carried out in the fields of the open clusters Pismis 8 and Pismis 13, located in the Vela-Puppis region in our Galaxy. MK spectral types have also been determined for a number of stars located in the fields of these two clusters which were used to secure membership among the brightest stars. Since our photometry goes to a fainter limit than previous studies we could provide better reddening, distance and age determinations. Both clusters are located close to the edge of the local arm in the third quadrant. Pismis 8 is a cluster about 5-7My old located at 2000pc from the Sun, while Pismis 13 was found at 2750pc with a probable age of about 100My. The estimate of the slopes of the mass functions in both cases yielded x=1.7 and x=2.1 for Pismis 8 and 13 respectively.
