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5281. Proper motions and BV photometry in NGC 1513
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.
5282. Proper motions and BVRI photometry in NGC 4147
ID:
ivo://CDS.VizieR/J/A+AS/142/373
Title:
Proper motions and BVRI photometry in NGC 4147
Short Name:
J/A+AS/142/373
Date:
21 Oct 2021
Publisher:
CDS
Description:
Astrometry and B VRI CCD photometry of 115 stars down to B=17.6 in the region of about 11'x11' around the globular cluster NGC 4147 was performed. In the astrometric reduction, three earlier epoch plates taken at Sheshan, Shanghai, China, in 1958 and four recent epoch B-passband CCD frames taken at Kavalur, India, were used. The data were reduced to a catalogue based on measurements of stars on seven plates with an epoch period from 1917 to 1979 taken in Bonn, Germany, and ultimately to the Hipparcos catalogue. The reduction was done with the central overlapping method. Based on the new proper motion data, the membership probabilities of 115 stars were determined. Furthermore, three colour-magnitude diagrams (CMD) of V versus B-V, V-R and V-I, respectively, for HB and GB stars were constructed from CCD photometry obtained with the Vainu Bappu Telescope. An absolute proper motion of the cluster of -2.08+/-0.48mas/yr in right ascension and -3.07+/-0.46mas/yr in declination has been obtained. The space velocity and apogalactic distance of the cluster with respect to the Galactic standard of rest were calculated. In contrast to the first results given in the literature we obtain a significantly lower velocity and a smaller apogalactic distance for NGC 4147.
5283. Proper motions and JHK of 24 Berkeley clusters
ID:
ivo://CDS.VizieR/J/MNRAS/389/285
Title:
Proper motions and JHK of 24 Berkeley clusters
Short Name:
J/MNRAS/389/285
Date:
21 Oct 2021
Publisher:
CDS
Description:
The main astrophysical parameters of 24 previously unstudied open clusters of Berkeley catalogue are presented here. JHK near-infrared (Two Micron All Sky Survey, Cat. II/246) photometry and the proper motions astrometry of Naval Observatory Merged Astrometric Dataset (NOMAD, Cat. I/297) are used. The clusters' centres, angular diameters, ages, distances and colour excesses for these clusters are estimated for the first time.
5284. Proper motions and membership in NGC 6366
ID:
ivo://CDS.VizieR/J/A+A/584/A59
Title:
Proper motions and membership in NGC 6366
Short Name:
J/A+A/584/A59
Date:
21 Oct 2021
Publisher:
CDS
Description:
NGC 6366 is a metal-rich globular cluster that is relatively unstudied. It is a kinematically interesting cluster, reported as belonging to the slowly rotating halo system, which is unusual given its metallicity and spatial location in the Galaxy. The purpose of this research is to determine the relative proper motion and membership probability of the stars in the region of globular cluster NGC 6366. To target cluster members reliably during spectroscopic surveys without including field stars, a good proper motion and membership probability catalogue of NGC 6366 is needed. To derive relative proper motions, the archival data from the Wide Field Imager mounted on the ESO 2.2m telescope have been reduced using a high precision astrometric software. The images used are in the B,V, and I photometric bands with an epoch gap of ~3.2yr. The calibrated BVI magnitudes have been determined using recent data for secondary standard stars.
5285. Proper motions and membership in NGC 3766
ID:
ivo://CDS.VizieR/J/MNRAS/430/3350
Title:
Proper motions and membership in NGC 3766
Short Name:
J/MNRAS/430/3350
Date:
21 Oct 2021
Publisher:
CDS
Description:
Relative proper motions (PMs) and cluster membership probabilities (P_mu_) were derived for ~2500 stars in the field of the open star cluster NGC 3766. The cluster was observed in the B and V broad-band filters at two epochs separated by ~6yr using a wide-field imager mounted on the WFI@ESO 2.2-m telescope. All CCD frames were reduced using the astrometric techniques described by Anderson et al. (2006A&A...454.1029A, Paper I). The PM rms error for stars brighter than V~15mag is 2.0mas/yr, but it gradually increases up to ~4mas/yr at V~20mag. Using PM data, membership probabilities were derived for the stars in the region of the cluster. They indicate that one Ap and three Be stars are members of the cluster. A reddening of E(B-V)=0.22+/-0.05mag, a distance of 2.5+/-0.5kpc and an age of ~20Myr were derived using stars with P_mu_>70 per cent. A mass function slope of x=1.60+/-0.10 was derived for the cluster, and the cluster was found to be dynamically relaxed. Finally, we provide positions, calibrated B and V magnitudes, relative PMs and membership probabilities for the stars in the field of NGC 3766. We have produced a catalogue that is electronically available to the astronomical community.
5286. Proper motions and photometry for members of Cha I
ID:
ivo://CDS.VizieR/J/AJ/154/46
Title:
Proper motions and photometry for members of Cha I
Short Name:
J/AJ/154/46
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have performed a search for planetary-mass brown dwarfs in the Chamaeleon I star-forming region using proper motions and photometry measured from optical and infrared images from the Spitzer Space Telescope, the Hubble Space Telescope, and ground-based facilities. Through near-IR spectroscopy at Gemini Observatory, we have confirmed six of the candidates as new late-type members of Chamaeleon I ({>=}M8). One of these objects, ChaJ11110675-7636030, has the faintest extinction-corrected M_K_ among known members, which corresponds to a mass of 3-6M_Jup_ according to evolutionary models. That object and two other new members have redder mid-IR colors than young photospheres at {<=}M9.5, which may indicate the presence of disks. However, since those objects may be later than M9.5 and the mid-IR colors of young photospheres are ill-defined at those types, we cannot determine conclusively whether color excesses from disks are present. If ChaJ11110675-7636030 does have a disk, it would be a contender for the least-massive known brown dwarf with a disk. Since the new brown dwarfs that we have found extend below our completeness limit of 6-10M_Jup_, deeper observations are needed to measure the minimum mass of the initial mass function in Chamaeleon I.
5287. Proper motions and photometry in NGC 2323
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).
5288. Proper motions and photometry of stars in M55
ID:
ivo://CDS.VizieR/J/A+A/543/A87
Title:
Proper motions and photometry of stars in M55
Short Name:
J/A+A/543/A87
Date:
21 Oct 2021
Publisher:
CDS
Description:
NGC 6809 is a luminous metal-poor halo globular cluster that is relatively easy to study due to its proximity and low concentration. Because of its high Galactic latitude (b=-23{deg}), interstellar reddening and contamination is not very high. We aim to determine the relative proper motion and membership probability of the stars in the wide area of globular cluster NGC 6809. To target cluster members reliably during spectroscopic surveys and both spatial and radial distributions in the cluster outskirts without including field stars, a good proper motion and membership probability catalogue of NGC 6809 is required.
5289. Proper motions and photometry of stars in NGC 3201
ID:
ivo://CDS.VizieR/J/AJ/153/134
Title:
Proper motions and photometry of stars in NGC 3201
Short Name:
J/AJ/153/134
Date:
21 Oct 2021
Publisher:
CDS
Description:
With a high value of heliocentric radial velocity, a retrograde orbit, and suspected to have an extragalactic origin, NGC 3201 is an interesting globular cluster for kinematical studies. Our purpose is to calculate the relative proper motions (PMs) and membership probability for the stars in the wide region of globular cluster NGC 3201. PM based membership probabilities are used to isolate the cluster sample from the field stars. The membership catalog will help address the question of chemical inhomogeneity in the cluster. Archive CCD data taken with a wide-field imager (WFI) mounted on the ESO 2.2m telescope are reduced using the high-precision astrometric software developed by Anderson et al. for the WFI images. The epoch gap between the two observational runs is ~14.3 years. To standardize the BVI photometry, Stetson's secondary standard stars are used. The CCD data with an epoch gap of ~14.3 years enables us to decontaminate the cluster stars from field stars efficiently. The median precision of PMs is better than ~0.8mas/yr for stars having V<18mag that increases up to ~1.5mas/yr for stars with 18<V<20mag. Kinematic membership probabilities are calculated using PMs for stars brighter than V~20mag. An electronic catalog of positions, relative PMs, BVI magnitudes, and membership probabilities in the ~19.7x17arcmin^2^ region of NGC 3201 is presented. We use our membership catalog to identify probable cluster members among the known variables and X-ray sources in the direction of NGC 3201.
5290. Proper motions and photometry of stars near NGC7380
ID:
ivo://CDS.VizieR/J/AJ/142/71
Title:
Proper motions and photometry of stars near NGC7380
Short Name:
J/AJ/142/71
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present proper motions, radial velocities, and a photometric study of the Galactic open cluster NGC 7380, which is associated with prominent emission nebulosity and dark molecular clouds. On the basis of the sample of highly probable member stars, the star cluster is found to be at a distance of 2.6+/-0.4kpc, has an age of around 4Myr, and a physical size of ~6pc across with a tidal structure. The binary O-type star DH Cep is a member of the cluster in its late stage of clearing the surrounding material, and may have triggered the ongoing star formation in neighboring molecular clouds which harbor young stars that are coeval and comoving with, but not gravitationally bound by, the star cluster.