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231. CT1 photometry in Tombaugh 1
ID:
ivo://CDS.VizieR/J/A+A/421/991
Title:
CT1 photometry in Tombaugh 1
Short Name:
J/A+A/421/991
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present CCD photometry in the Washington system C and T1 passbands down to T1~18.5mag in the field of Tombaugh 1, a little studied open cluster located in the third Galactic quadrant. We measured T1 magnitudes and C-T1 colours for a total of 1351 stars distributed throughout an area of 13.6'x13.6'.
232. Cyg OB2 XMM observations
ID:
ivo://CDS.VizieR/J/A+A/536/A31
Title:
Cyg OB2 XMM observations
Short Name:
J/A+A/536/A31
Date:
21 Oct 2021
Publisher:
CDS
Description:
Cyg OB2 is one of the most massive associations of O-type stars in our Galaxy. Despite the large interstellar reddening towards Cyg OB2, many studies, spanning a wide range of wavelengths, have been conducted to more clearly understand this association. X-ray observations provide a powerful tool to overcome the effect of interstellar absorption and study the most energetic processes associated with the stars in Cyg OB2. We analyse XMM-Newton data to investigate the X-ray and UV properties of massive O-type stars as well as low-mass pre-main sequence stars in Cyg OB2.
233. DANCe study of M35 (NGC 2168)
ID:
ivo://CDS.VizieR/J/A+A/575/A120
Title:
DANCe study of M35 (NGC 2168)
Short Name:
J/A+A/575/A120
Date:
21 Oct 2021
Publisher:
CDS
Description:
Messier 35 (NGC 2168) is an important young nearby cluster. Its age, richness and relative proximity make it a privileged target for stellar evolution studies. The Kepler K2 mission recently observed it and provided high accuracy photometric time series of a large number of sources in this area of the sky. Identifying the cluster's members is therefore of high importance to optimize the interpretation and analysis of the Kepler K2 data. We aim at identifying the cluster's members by deriving membership probabilities for the sources within 1 degree of the cluster's center, going further away than equivalent previous studies. We measure accurate proper motions and multi-wavelength (optical and near-infrared) photometry using ground based archival images of the cluster. We use these measurements to compute membership probabilities. The list of candidate members from Barrado y Navascues et al. (2001ApJ...546.1006B, Cat. J/ApJ/546/1006) is used as training set to identify the cluster's locus in a multi-dimensional space made of proper motions, luminosities and colors. The final catalog includes 338892 sources with multi-wavelength photometry. Approximately half (194452) were detected at more than two epochs and we measured their proper motion and used it to derive membership probability. A total of 4349 candidate members with membership probabilities greater than 50% are found in this sample in the luminosity range between 10 and 22mag. The slow proper motion of the cluster and the overlap of its sequence with the field and background sequences in almost all color-magnitude and color-color diagrams complicate the analysis and the contamination level is expected to be significant. Our study nevertheless provides a coherent and quantitative membership analysis of Messier 35 based on a large fraction of the best ground-based data sets obtained over the past 18 years. As such, it represents a valuable input for follow-up studies using in particular the Kepler K2 photometric time series.
234. Danks 1, Danks 2, and RCW 79 variables
ID:
ivo://CDS.VizieR/J/A+A/545/A54
Title:
Danks 1, Danks 2, and RCW 79 variables
Short Name:
J/A+A/545/A54
Date:
21 Oct 2021
Publisher:
CDS
Description:
The ESO Public Survey "VISTA Variables in the Via Lactea"' (VVV) provides deep multi-epoch infrared observations for unprecedented 562 sq. degrees of the Galactic bulge, and adjacent regions of the disk. The VVV observations will foster the construction of a sample of Galactic star clusters with reliable and homogeneously derived physical parameters (e.g., age, distance, and mass, etc.). In this first paper in a series, the methodology employed to establish cluster parameters for the envisioned database are elaborated upon by analysing four known young open clusters: Danks1, Danks2, RCW79, and DBS132. The analysis offers a first glimpse of the information that can be gleaned from the VVV observations for clusters in the final database. Wide-field, deep JHK_s_ VVV observations, combined with new infrared spectroscopy, are employed to constrain fundamental parameters for a subset of clusters. Results are inferred from VVV near-infrared photometry and numerous low resolution spectra (typically more than 10 per cluster). The high quality of the spectra and the deep wide-field VVV photometry enables us to precisely and independently determine the characteristics of the clusters studied, which we compare to previous determinations. An anomalous reddening law in the direction of the Danks clusters is found, specifically E(J-H)/E(H-Ks)=2.20+/-0.06, which exceeds published values for the inner Galaxy. The G305 star forming complex, which includes the Danks clusters, lies beyond the Sagittarius-Carina spiral arm and occupies the Centaurus arm. Finally, the first deep infrared colour-magnitude diagram of RCW79 is presented, which reveals a sizeable pre-main sequence population. A list of candidate variable stars in G305 region is reported. This study demonstrates the strength of the dataset and methodology employed, and constitutes the first step of a broader study which shall include reliable parameters for a sizeable number of poorly characterised and/or newly discovered clusters.
235. Debris disks in NGC 2232
ID:
ivo://CDS.VizieR/J/ApJ/688/597
Title:
Debris disks in NGC 2232
Short Name:
J/ApJ/688/597
Date:
21 Oct 2021
Publisher:
CDS
Description:
We describe Spitzer IRAC and MIPS observations of the nearby 25Myr old open cluster NGC 2232. Combining these data with ROSAT All-Sky Survey observations, proper motions, and optical photometry/spectroscopy, we construct a list of highly probable cluster members. We identify one A-type star, HD 45435, that has definite excess emission at 4.5-24um indicative of debris from terrestrial planet formation. We also identify 2-4 late-type stars with possible 8um excesses and 8 early-type stars with definite 24um excesses. Constraints on the dust luminosity and temperature suggest that the detected excesses are produced by debris disks. From our sample of B and A stars, stellar rotation appears to be correlated with 24um excess, a result that would be expected if massive primordial disks evolve into massive debris disks. To explore the evolution of the frequency and magnitude of debris around A-type stars, we combine our results with data for other young clusters.
236. Decoding the morphological evolution of open clusters
ID:
ivo://CDS.VizieR/J/A+A/656/A49
Title:
Decoding the morphological evolution of open clusters
Short Name:
J/A+A/656/A49
Date:
22 Feb 2022
Publisher:
CDS
Description:
The properties of open clusters such as metallicity, age, and morphology are useful tools in studies of the dynamic evolution of open clusters. The morphology of open clusters can help us better understand the evolution of such structures. We aim to analyze the morphological evolution of 1256 open clusters by combining the shapes of the sample clusters in the proper motion space with their morphology in the two-dimensional spherical Galactic coordinate system, providing their shape parameters based on a member catalog derived from Gaia Second Data Release as well as data from the literature. We applied a combination of a nonparametric bivariate density estimation with the least square ellipse fitting to derive the shape parameters of the sample clusters. We derived the shape parameters of the sample clusters in the two-dimensional spherical Galactic coordinate system and that of the proper motion space. By analyzing the dislocation of the sample clusters, we find that the dislocation, d; is related to the X-axis pointing toward the Galactic center, Y-axis pointing in the direction of Galactic rotation, and the Z-axis (log(|H|/pc)) that is positive toward the Galactic north pole. This finding underlines the important role of the dislocation of clusters in tracking the external environment of the Milky Way. The orientation (q_pm_) of the clusters, with e_pm_>=0.4, presents an aggregate distribution in the range of -45{deg} to 45{deg}, comprising about 74% of them. This probably suggests that these clusters tend to deform heavily in the direction of the Galactic plane. NGC 752 is in a slight stage of expansion in the two-dimensional space and will become deformed, in terms of its morphology, along the direction perpendicular to the original stretching direction in the future if no other events occur. The relative degree of deformation of the sample clusters in the short-axis direction decreases as their ages increase. On average, the severely distorted sample clusters in each group account for about 26%~9%. This possibly implies a uniform external environment in the range of |H|<=300pc if the sample completeness of each group is not taken into account.
237. Deep all-sky census of the Hyades
ID:
ivo://CDS.VizieR/J/A+A/531/A92
Title:
Deep all-sky census of the Hyades
Short Name:
J/A+A/531/A92
Date:
21 Oct 2021
Publisher:
CDS
Description:
On the basis of the PPMXL catalogue we perform an all-sky census of the Hyades down to masses of about 0.2M_{sun}_ in a region up to 30pc from the cluster centre. We use the proper motions from PPMXL in the convergent point method to determine probable kinematic members. From 2MASS photometry and CMC14 r'-band photometry, we derive empirical colour-absolute magnitude diagrams and, finally, determine photometric membership for all kinematic candidates. This is the first deep (r'<17) all-sky survey of the Hyades allowing a full three-dimensional analysis of the cluster. The survey is complete down to at least M_{K_s_}_=7.3 or 0.25M_{sun}_. We find 724 stellar systems co-moving with the bulk Hyades space velocity, which represent a total mass of 435M_{sun}_. The tidal radius is about 9pc, and 275M_{sun}_ (364 systems) are gravitationally bound. This is the cluster proper. Its mass density profile is perfectly fitted by a Plummer model with a central density of 2.21M_{sun}_/pc^3^ and a core radius of r_co_=3.10pc, while the half-mass radius is r_h_=4.1pc. There are another 100M_{sun}_ in a volume between one and two tidal radii (halo), and another 60M_{sun}_ up to a distance of 30pc from the centre. Strong mass segregation is inherent in the cluster. The present-day luminosity and mass functions are noticeably different in various parts of the cluster (core, corona, halo, and co-movers). They are strongly evolved compared to presently favoured initial mass functions. The analysis of the velocity dispersion of the cluster shows that about 20% of its members must be binaries. As a by-product, we find that presently available theoretical isochrones are not able to adequately describe the near-infrared colour-absolute magnitude relation for those cluster stars that are less massive than about 0.6M_{sun}_.
238. Deep MIPS observations of IC 348 nebula
ID:
ivo://CDS.VizieR/J/AJ/138/703
Title:
Deep MIPS observations of IC 348 nebula
Short Name:
J/AJ/138/703
Date:
21 Oct 2021
Publisher:
CDS
Description:
We describe new, deep MIPS photometry and new high signal-to-noise optical spectroscopy of the 2.5Myr old IC 348 Nebula. To probe the properties of the IC 348 disk population, we combine these data with previous optical/infrared photometry and spectroscopy to identify stars with gas accretion, to examine their mid-IR colors, and to model their spectral energy distributions.
239. Deep proper-motion survey of Blanco 1
ID:
ivo://CDS.VizieR/J/MNRAS/413/1024
Title:
Deep proper-motion survey of Blanco 1
Short Name:
J/MNRAS/413/1024
Date:
21 Oct 2021
Publisher:
CDS
Description:
We provide two comprehensive catalogues of positions and proper motions in the area of open cluster Blanco 1. The main catalogue, CtlgM (table1), contains 6271 objects down to V~18.5 and covers a circular ~11deg^2^ area. The accuracy of CtlgM proper motions, at about 0.3-0.5mas/yr for well-measured stars, permits an excellent segregation between the cluster and field stars.
240. Deep UVBRI photometry in IC 348
ID:
ivo://CDS.VizieR/J/A+A/324/549
Title:
Deep UVBRI photometry in IC 348
Short Name:
J/A+A/324/549
Date:
21 Oct 2021
Publisher:
CDS
Description:
Table3 contains UBVRI-CCD photometry for the 123 observed stars in the nucleus of IC 348 open cluster. Magnitude and colours are given with their corresponding errors. Column "N" gives the number of observations. Spectral types and cross-identifications with other catalogues are given in note file. Table5 contains adopted reddening solution for the brightest members in IC 348

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