- 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.
Number of results to display per page
Search Results
- 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.
- 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/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.
- 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.
- 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.
- ID:
- ivo://CDS.VizieR/J/ApJ/710/1032
- Title:
- Proper motions in {omega} Cen
- Short Name:
- J/ApJ/710/1032
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze data from the Hubble Space Telescope's (HST) Advanced Camera for Surveys of the globular cluster (GC) Omega Cen. We construct a photometric catalog of 1.2x10^6^ stars over a 10'x10' central field down to below B_F435W_=25 (M~0.35M_{sun}_). The 2.5 to 4 year baseline between observations yields a catalog of some 10^5^ proper motions over a smaller area, with 53382 "high-quality" measurements in a central R<~2' field. Artificial-star tests characterize the photometric incompleteness. We determine the cluster center to ~1" accuracy from star counts using two different methods, one based on isodensity contours and the other on "pie slices." We independently confirm the result by determining also the kinematical center of the HST proper motions, as well as the center of unresolved light seen in Two Micron All Sky Survey data. All results agree to within their 1"-2" levels of uncertainty. The proper-motion dispersion of the cluster increases gradually inward, but there is no variation in kinematics with position within the central ~15": there is no dispersion cusp and no stars with unusually high velocities. We measure for the first time in any GC the variation in internal kinematics along the main sequence.
- ID:
- ivo://CDS.VizieR/J/AJ/134/1432
- Title:
- Proper motions in Plaut's window
- Short Name:
- J/AJ/134/1432
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A proper-motion study of a field of 20'x20' inside Plaut's low-extinction window (l,b) = (0{deg}, -8{deg}) has been completed. Relative proper motions and photographic BV photometry have been derived for ~21000 stars reaching to V~20.5mag, based on the astrometric reduction of 43 photographic plates, spanning over 21yr of epoch difference. Proper-motion errors are typically 1mas/yr, and field-dependent systematics are below 0.2mas/yr. Cross-referencing with the 2MASS catalog yielded a sample of ~8700 stars, from which predominantly disk and bulge subsamples were selected photometrically from the JH color-magnitude diagram. The two samples exhibited different proper-motion distributions, with the disk displaying the expected reflex solar motion as a function of magnitude.
- ID:
- ivo://CDS.VizieR/J/ApJ/875/77
- Title:
- Proper motions of MW satellites with Gaia & DES
- Short Name:
- J/ApJ/875/77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new, probabilistic method for determining the systemic proper motions of Milky Way (MW) ultra-faint satellites in the Dark Energy Survey (DES). We utilize the superb photometry from the first public data release (DR1) of the DES to select candidate members and cross-match them with the proper motions from the Gaia DR2. We model the candidate members with a mixture model (satellite and MW) in spatial and proper motion space. This method does not require prior knowledge of satellite membership and can successfully determine the tangential motion of 13 DES satellites. With our method, we present measurements of the following satellites: Columba I, Eridanus III, Grus II, Phoenix II, Pictor I, Reticulum III, and Tucana IV. This is the first systemic proper motion measurement for several of these satellites, and the majority lack extensive spectroscopic follow-up studies. We compare these to the predictions of Large Magellanic Cloud satellites and the vast polar structure. With the high-precision DES photometry, we conclude that most of the newly identified member stars are very metal-poor ([Fe/H]<=-2), similar to other ultra-faint dwarf galaxies, while Reticulum III is likely more metal-rich. We also find potential members in the following satellites that might indicate their overall proper motion: Cetus II, Kim 2, and Horologium II. However, due to the small number of members in each satellite, spectroscopic follow-up observations are necessary to determine the systemic proper motion in these satellites.
- ID:
- ivo://CDS.VizieR/J/A+A/502/91
- Title:
- Proper motions of stars near SgrA*
- Short Name:
- J/A+A/502/91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used multi-epoch adaptive optics assisted near-infrared observations of the central parsec of the Galaxy obtained with NACO/CONICA at the ESO VLT. Stellar positions were measured via PSF fitting in the individual images and transformed into a common reference frame via suitable sets of reference stars. We measured the proper motions of more than 6000 stars within about 1pc projected distance of the supermassive black hole Sagittarius A*. The table contains for each measured star its projected distance from Sagittarius A*, its offsets in right ascension and declination from Sagittarius A* along with the corresponding uncertainties, its proper motion and the corresponding uncertainty in right ascension and declination, the Ks-band magnitude and the corresponding uncertainty, and its classification as early type in case such a classification exists.
