- 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.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/545/A139
- Title:
- Radial Velocities of stars observed in M67
- Short Name:
- J/A+A/545/A139
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Precise stellar radial velocities are used to search for massive (Jupiter masses or higher) exoplanets around the stars of the open cluster M67. We observed a total of 88 main-sequence stars, subgiants, and giants all highly probable members of M67, using four telescopes and instrument combinations: the HARPS spectrograph at the ESO 3.6m, the SOPHIE spectrograph at OHP, the CORALIE spectrograph at the Euler Swiss telescope and the HRS spectrograph at Hobby Eberly Telescope. We investigate whether exoplanets are present by obtaining radial velocities with precisions as good as 10m/s.
- ID:
- ivo://CDS.VizieR/J/AJ/162/56
- Title:
- Radial velocity of 240 YSOs with MMT/Hectochelle
- Short Name:
- J/AJ/162/56
- Date:
- 14 Mar 2022 06:56:34
- Publisher:
- CDS
- Description:
- Stellar kinematics is a powerful tool for understanding the formation process of stellar associations. Here, we present a kinematic study of the young stellar population in the Rosette nebula using recent Gaia data and high-resolution spectra. We first isolate member candidates using the published mid-infrared photometric data and the list of X-ray sources. A total of 403 stars with similar parallaxes and proper motions are finally selected as members. The spatial distribution of the members shows that this star-forming region is highly substructured. The young open cluster NGC2244 in the center of the nebula has a pattern of radial expansion and rotation. We discuss its implication on the cluster formation, e.g., monolithic cold collapse or hierarchical assembly. On the other hand, we also investigate three groups located around the border of the HII bubble. The western group seems to be spatially correlated with the adjacent gas structure, but their kinematics is not associated with that of the gas. The southern group does not show any systematic motion relative to NGC2244. These two groups might be spontaneously formed in filaments of a turbulent cloud. The eastern group is spatially and kinematically associated with the gas pillar receding away from NGC2244. This group might be formed by feedback from massive stars in NGC2244. Our results suggest that the stellar population in the Rosette Nebula may form through three different processes: the expansion of stellar clusters, hierarchical star formation in turbulent clouds, and feedback-driven star formation.
- ID:
- ivo://CDS.VizieR/J/A+A/535/A39
- Title:
- Radial velocity survey toward NGC 6253
- Short Name:
- J/A+A/535/A39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- One of the most metal-rich open cluster of the Galaxy, NGC 6253 is a target of special interest in the search for extrasolar planets, the study of stellar populations, and the chemical/dynamical evolution of the Galactic disk. We present the results of two photometric campaigns and a VLT multi-epoch radial velocity survey toward the open cluster NGC 6253. We complement our analysis with photometric, proper motion, and radial velocity data available from previous studies of this cluster, and analyze three planetary candidates found in the field of NGC 6253.
- ID:
- ivo://CDS.VizieR/J/AJ/124/1418
- Title:
- Radio-optical identification of star clusters
- Short Name:
- J/AJ/124/1418
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A reexamination of the correspondence between 6cm radio continuum sources and young star clusters in the Antennae galaxies indicates that ~85% of the strong thermal sources have optical counterparts, once the optical image is shifted 1.2" to the southwest. A sample of 37 radio-optical matches are studied in detail, showing correlations between radio properties (i.e., total flux and spectral index) and a variety of optical characteristics (i.e., intrinsic cluster brightness, H{alpha} flux and equivalent width, extinction, and cluster ages). There is a strong correlation between the radio flux and the intrinsic optical brightness.
- ID:
- ivo://CDS.VizieR/J/A+A/600/A106
- Title:
- RAVE open cluster pairs, groups and complexes
- Short Name:
- J/A+A/600/A106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Galactic open clusters (OCs) mainly belong to the young stellar population in the Milky Way disk, but are there groups and complexes of OCs that possibly define an additional level in hierarchical star formation? Current compilations are too incomplete to address this question, especially regarding radial velocities (RVs) and metallicities ([M/H]). Here we present the parameters for the final working sample of 432 open clusters, as well as the mean parameters for the 19 detected potential open cluster groupings.
- ID:
- ivo://CDS.VizieR/J/MNRAS/351/1401
- Title:
- RcIcZ photometry of NGC 2547
- Short Name:
- J/MNRAS/351/1401
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of RcIcZ photometry over an area of 0.855 square degrees, centred on the young open cluster NGC 2547. The survey is substantially complete to limits of Rc=21.5, Ic=19.5, Z=19.5. We use the catalogue to define a sample of NGC 2547 candidates with model-dependent masses of about 0.05-1.0M_{sun}_.
- ID:
- ivo://CDS.VizieR/J/A+A/376/561
- Title:
- Rc light curves of 7 variables in M37
- Short Name:
- J/A+A/376/561
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A CCD photometric study of the dense galactic open cluster M 37 is discussed. The majority of the analysed data have been obtained through an R_C_ filter in order to collect time-series measurements. The observations were carried out on seven nights between December 1999 and February 2000, and have led to the discovery of 7 new variable stars in the field. Three of them have been unambiguously identified as W UMa-type eclipsing binaries, while two more are monoperiodic pulsating stars, most probably high-amplitude {delta} Scuti-type variables. Two stars seem to be long-period eclipsing binaries without firm period determination. The individual light curve data are presented here.
- ID:
- ivo://CDS.VizieR/J/A+A/359/347
- Title:
- Reddening in open and globular clusters
- Short Name:
- J/A+A/359/347
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper compares reddening values E(B-V) derived from the stellar content of 103 old open clusters and 147 globular clusters of the Milky Way with those derived from DIRBE/IRAS 100{mu}m dust emission in the same directions. Star clusters at |b|>20{deg} show comparable reddening values between the two methods, in agreement with the fact that most of them are located beyond the disk dust layer. For very low galactic latitude lines of sight, differences occur in the sense that DIRBE/IRAS reddening values can be substantially larger, suggesting effects due to the depth distribution of the dust. The differences appear to arise from dust in the background of the clusters consistent with a dust layer where important extinction occurs up to distances from the Plane of =~300pc. For 3% of the sample a significant background dust contribution might be explained by higher dust clouds. We find evidence that the Milky Way dust lane and higher dust clouds are similar to those of several edge-on spiral galaxies recently studied in detail by means of CCD imaging.
- ID:
- ivo://CDS.VizieR/J/AN/329/609
- Title:
- Red giant candidates in 10 open clusters
- Short Name:
- J/AN/329/609
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As part of a long-term project to determine abundances and astrophysical properties of evolved red stars in open clusters, we present high-precision DDO photoelectric observations for a sample of 33 red giant candidates projected in the fields of nine Galactic open clusters. These data are supplemented with UBV photoelectric photometry of 24 of these stars as well as with CORAVEL radial-velocity observations for 13 red giant candidates in four of the clusters. We also present Washington photoelectric photometry of a small sample of red giant candidates of the open cluster Ruprecht 97. The likelihood of cluster membership for each star photometrically observed and for 23 additional red giant candidates with UBV and DDO data available in the literature, is evaluated by using two independent photometric criteria. Nearly 82% of the analysed stars are found to have a high probability of being cluster giants. Photometric membership probabilities show very good agreement with those obtained from CORAVEL radial velocities. While E(B-V) colour excesses were determined from combined B-V and DDO colours, calibrations of the DDO system were used to derive MK spectral types, effective temperatures and metallicities.The derived DDO metallicities range between values typical of moderately metal-poor clusters ([Fe/H]=-0.19) to moderately metal-rich ([Fe/H]=0.25) ones.