- ID:
- ivo://CDS.VizieR/J/A+A/396/125
- Title:
- Proper motions and BV photometry in NGC 1513
- Short Name:
- J/A+A/396/125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of astrometric and photometric investigations of the poorly studied open cluster NGC 1513 are presented. The proper motions of 333 stars with a root-mean-square error of 1.9mas/yr were obtained by means of the automated measuring complex "Fantasy". Eight astrometric plates covering the time interval of 101 years were measured and a total of 141 astrometric cluster members identified. BV CCD-photometry was obtained for stars in an area 17'x17' centered on the cluster. Altogether 33 stars with high reliability were considered to be cluster members by two criteria. The estimated age of NGC 1513 is 2.54E+08 years.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/PAZh/38/95
- Title:
- Proper motions and photometry in NGC 2323
- Short Name:
- J/PAZh/38/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of a comprehensive study of the Galactic open cluster NGC 2323 are presented. The positions of stars to a limiting magnitude B<=16.7mag in a 42.5x42.5arcmin area centered on the cluster were measured on six plates from the Pulkovo normal astrograph with a maximum epoch difference of 60yr. The measurements were performed with the Pulkovo "Fantasy" automated measuring system upgraded in 2010. The corresponding areas from the USNO-A2.0, USNO-B1, and 2MASS catalogues were used as additional plates. As a result, the relative proper motions of stars were obtained with a root-mean-square error of 5.85mas/yr. A catalogue of UBV and JHK magnitudes for objects in the investigated area was compiled from available published resources. The astrometric selection of cluster members was made by the maximum likelihood method. A high individual cluster membership probability of a star (P>=80%) served as the first selection criterion. The position of a star on the photometric color-magnitude (V-(B-V), J-(J-K)) diagrams of the cluster was considered as the second criterion. The position of an object on the color- color ((U-B)-(B-V), (J-H)-(J-K)) diagrams served as the third criterion. On the basis of these criteria, it was established that 508 stars are members of NGC 2323. These data were used to refine the physical parameters of the cluster: the mean reddening E(B-V)=0.25mag, the true distance modulus (V-M_V_)=9.85mag, and the cluster age of about 140Myr from the grid of isochrones computed by the Padova group for solar chemical composition. Two tables contain the catalogues of proper motions and photometry for stars in the area. The luminosity and mass functions were constructed. The cluster membership of red and blue giants, variable, double, and multiple stars was considered. The position of the cluster center was improved: alpha=07:02:47.5, delta=-08:20:16 (2000.0).
- ID:
- ivo://CDS.VizieR/V/27
- Title:
- Proper Motions and UBV Photometry in h+{chi} Per
- Short Name:
- V/27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Proper motions with an 80 year baseline have been determined relative to reference stars with B=13.9mag. determined for 3086 stars brighter than B=15.5mag. within an area of 50' radius, centered at RA=2h16.9m, Dec=+57{deg}01' (1950.0). Two pairs of Tashkent normal astrograph plates with a mean epoch difference of 80 years was used. Proper motions were also measured for 1055 stars with 15.5 <= B <= 17.1 mag. in two areas 14' in radius, centered on the h and {chi} Persei clusters. Proper motions are also given for 1386 stars in an adjacent area (RA=2h06.7m, Dec=+56{deg}57') for 1386 stars with a 38 year baseline. The mean errors of the proper motions are equal in right ascension and declination. For the h and {chi} Perseus region, they are 0.0021"/yr and for the adjacent region, they are 0.0031"/yr. The proper motions in the adjacent area have been reduced to the system of those in the cluster region using 214 stars in common. UBV magnitudes of the stars were determined using plates taken with the 80/120/240 Schmidt telescope of the Radioastrophysical Observatory of the Academy of Sciences of the Latvian SSR and photoelectric standards published by Johnson and Morgan (1955ApJ...122..429J) and Widley (1964ApJS....8..439W). The number of measured plates and the corresponding errors are given in the following table: ----------------------------------------------------- FILE NAME # PLATES ERRORS (0.01mag) V B U V B U ----------------------------------------------------- data1.dat 2 3 2 6 5 6 data2.dat 1 2 - 8 6 - adjarea.dat 2 2 2 6 6 6 _____________________________________________________ Cluster members were selected on the basis of their proper motion and photometric criteria. The membership probability was calculated on the assumption of a normal distribution of the proper motions around the cluster proper motion.
- ID:
- ivo://CDS.VizieR/J/A+A/401/531
- Title:
- Proper motions in NGC 7243
- Short Name:
- J/A+A/401/531
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of astrometric and photometric investigations of the open cluster NGC 7243 are presented. Proper motions of 2165 stars with root-mean-square error of 1.1mas/yr were obtained by means of PDS scanning of astrometric plates covering the time interval of 97 years. A total of 211 cluster members down to V=15.5mag have been identified. V and B magnitudes have been determined for 2118 and 2110 stars respectively. Estimations of mass 348M_{sun}_<M<522M_{sun}_, age t=2.510^8^yr, distance r=698pc and reddening E(B-V)=0.24 of the cluster NGC 7243 have been made.
- ID:
- ivo://CDS.VizieR/V/28
- Title:
- Proper Motions, UBV Photometry, Four Open Clusters
- Short Name:
- V/28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Proper motions were determined for 2169 stars with limiting magnitude B = 16.5 mag and located within a 60x60' area centered at RA = 23h54.2min, Dec = 60deg57arcmin (1950.0). Three plate pairs with a mean epoch difference of 49 years were used. The first epoch plates were taken with the Tashkent normal astrograph during 1923-1925 and the second epoch plates with the Pulkovo normal astrograph. The proper motions have a mean error +/-0.0030 arcsec (B < 14.5 mag) and +/-0.0036 arcsec (B > 14.5 mag) and were measured relative to reference stars with 13.5 mag <= B <= 14.5 mag. Photographic UBV magnitudes were measured using Sandages photoelectric standards. The U, B and V magnitudes were determined for 1930, 2165 and 1734 stars respectively, with the corresponding mean errors +/-0.03 mag, +/-0.06 mag and +/-0.05 mag. In the measured area there are three known open clusters (NGC 7788, NGC 7790 and Berkeley 58) and a previously unknown open cluster, discovered by the author, centered at RA =23 h 54.9 min, Dec = 61 deg 21 arcmin (1950.0). The cluster members were selected on the basis of the proper motion (vector diagram) and photometric (V ~ B-V and U-B ~ B-V) criteria. Stars within areas with 4 arcmin radii centered on NGC 7788 and NGC 7790 and 6 arcmin radii centered on Berkeley 58 and the anonymous cluster were investigated for cluster membership. The method of reduction of the observational data and the results obtained have been published in Izv. Pulkovo 195, 80, 1977 and 196, 69, 1979.
- ID:
- ivo://CDS.VizieR/J/A+A/513/A29
- Title:
- RACE-OC project: M11 (NGC6705)
- Short Name:
- J/A+A/513/A29
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Rotation and magnetic activity are intimately linked in main-sequence stars of G or later spectral types. The presence and level of magnetic activity depend on stellar rotation, and rotation itself is strongly influenced by strength and topology of the magnetic fields. Open clusters represent especially useful targets to investigate the rotation/activity/age connection. The open cluster M11 has been studied as a part of the RACE-OC project (Rotation and ACtivity Evolution in Open Clusters), which is aimed at exploring the evolution of rotation and magnetic activity in the late-type members of open clusters with different ages. Photometric observations of the open cluster M11 were carried out in June 2004 using LOAO 1m telescope. The rotation periods of the cluster members are determined by Fourier analysis of photometric data time series. We further investigated the relations between the surface activity, characterized by the light curve amplitude, and rotation. We have discovered a total of 75 periodic variables in the M11 FoV, of which 38 are candidate cluster members. Specifically, among cluster members we discovered 6 early-type, 2 eclipsing binaries and 30 bona-fide single periodic late-type variables. Considering the rotation periods of 16 G-type members of the almost coeval 200-Myr M34 cluster, we could determine the rotation period distribution from a more numerous sample of 46 single G stars at an age of about 200-230 Myr and determine a median rotation period P=4.8d. A comparison with the younger M35 cluster (~150Myr) and with the older M37 cluster (~550Myr) shows that G stars rotate slower than younger M35 stars and faster than older M37 stars. The measured variation of the median rotation period is consistent with the scenario of rotational braking of main-sequence spotted stars as they age.
- ID:
- ivo://CDS.VizieR/J/AJ/145/134
- Title:
- Radial velocities of 108 stars in Ruprecht 147
- Short Name:
- J/AJ/145/134
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Ruprecht 147 is a hitherto unappreciated open cluster that holds great promise as a standard in fundamental stellar astrophysics. We have conducted a radial velocity survey of astrometric candidates with Lick, Palomar, and MMT observatories and have identified over 100 members, including 5 blue stragglers, 11 red giants, and 5 double-lined spectroscopic binaries (SB2s). We estimate the cluster metallicity from spectroscopic analysis, using Spectroscopy Made Easy (SME), and find it to be [M/H]=+0.07+/-0.03. We have obtained deep CFHT/MegaCam g'r'i'z' photometry and fit Padova isochrones to the (g'-i') and Two Micron All Sky Survey (J-K_S_) color-magnitude diagrams, using the {tau}^2^ maximum-likelihood procedure of Naylor, and an alternative method using two-dimensional cross-correlations developed in this work. We find best fits for Padova isochrones at age t=2.5+/-0.25Gyr, m-M=7.35+/-0.1, and A_V_=0.25+/-0.05, with additional uncertainty from the unresolved binary population and possibility of differential extinction across this large cluster. The inferred age is heavily dependent on our choice of stellar evolution model: fitting Dartmouth and PARSEC models yield age parameters of 3Gyr and 3.25Gyr, respectively. At ~300pc and ~3Gyr, Ruprecht 147 is by far the oldest nearby star cluster.
- ID:
- ivo://CDS.VizieR/J/A+AS/116/75
- Title:
- Region of the open cluster Tr 14
- Short Name:
- J/A+AS/116/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present UBVRI CCD imaging photometry down to approximately V=19mag in the area of the very young open cluster Tr 14. Our results confirm the existence of an anomalous extinction law in the area if it is interpreted in terms of the UBVRI photometry. According to our analysis the cluster distance is d=3100 (V_0_-M_V_=12.50mag) and its age is 1.5+/-.5x10^6^y. We want to draw the attention on stars which, from the observed magnitude-spread at constant color, could be stars in an early stage of evolution. In that case, the observed spread leads to assume that the process of star formation in Tr 14 is continuous whereas, from pre-main sequence evolutionary tracks, a duration of about 5x10^6^y is deduced for it. The computation of the cluster initial mass function reveals a flat slop e even though it still compares to a Salpeter law. At the same time, we found a spatial variation of the cluster IMF, which could be explained by mass segregation in the star formation process. The cluster youth and its compact appearance seem to confirm that it is far from virial equilibrium. The observed tot al cluster mass is around 2000M_{sun}_ and its core contains about 40% of the total.
- ID:
- ivo://CDS.VizieR/J/AN/325/705
- Title:
- RIJHKs of low-mass stars in sigma Ori
- Short Name:
- J/AN/325/705
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an RI photometric survey covering an area of 430 arcmin^2^ around the multiple star sigma Orionis. The observations were conducted with the 0.8m IAC-80 Telescope at the Teide Observatory. The survey limiting R and I magnitudes are 22.5 and 21, and completeness magnitudes 21 and 20, respectively. We have selected 53 candidates from the I vs. R-I colour-magnitude diagram (I=14-20) that follow the previously known photometric sequence of the cluster. Adopting an age of 2-4 Myr for the cluster, we find that these objects span a mass range from 0.35M_{sun}_ to 0.015M_{sun}_. We have performed J-band photometry of 52 candidates and K_s photometry for 12 of them, with the result that 50 follow the expected infrared sequence for the cluster, thus confirming with great confidence that the majority of the candidates are bona fide members. JHK_s photometry from the Two Micron All Sky Survey (2MASS, Cat. <II/246>) is available for 50 of the candidates and are in good agreement with our data. Out of 48 candidates, which have photometric accuracies better than 0.1mag in all bands, only three appear to show near-infrared excesses.
- ID:
- ivo://CDS.VizieR/J/A+A/344/943
- Title:
- Sh 138 BVRIJHK photometry
- Short Name:
- J/A+A/344/943
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a photometric and spectroscopic study of the compact HII region Sh 138 and its associated stellar cluster. The positions and BVRIJHK magnitudes are obtained for more than 400 stars over a field of about 4' square centred on the HII region. Sh 138 is excited by a cluster of young massive stars. At the cluster's very centre are at least four O-B2 stars separated by less than 4". The brightest of these, both in the visible and the near infrared, exhibits a spectrum similar to those of the more massive Herbig Ae/Be stars. This star, our No. 183, is overluminous by a factor of 2.5 in the visible and four in the near IR with respect to the O9.5V star required to account for the ionization level of the HII region. However star 183's position in the J-H versus H-K diagram does not indicate a near-IR excess. We suggest that this star is a young massive object belonging to a binary or multiple system. The stellar cluster associated with Sh 138 is very reminiscent of the Orion Trapezium cluster: it is centrally peaked around several massive stars, and is dense - more than 550stars/pc^2^ at its centre. The visual extinction in the cluster varies between 5mag and more than 35mag; large variations are observed over very small scales (for example, more than 20mag over less than 4" among the central massive stars).