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Start Over Subject astrometry Validation Level 2
351. 24 nearby open clusters TGAS and HSOY reanalysis
ID:
ivo://CDS.VizieR/J/A+A/615/A12
Title:
24 nearby open clusters TGAS and HSOY reanalysis
Short Name:
J/A+A/615/A12
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have determined stellar membership based on astrometry, primarily from TGAS and HSOY, and multi-band photometry for 24 clusters within 333 pc. The fundamental cluster parameters (distance, age, and reddening) have been derived by fitting Padova isochrones (Bressan et al. 2012) to the cluster photometry using a chi-squared minimization.
352. Near Earth Asteroids positions
ID:
ivo://CDS.VizieR/J/A+A/511/A40
Title:
Near Earth Asteroids positions
Short Name:
J/A+A/511/A40
Date:
21 Oct 2021
Publisher:
CDS
Description:
The EUROpean Near Earth Asteroid Research (EURONEAR) is a network which envisions to bring some European contributions into the general context traced by the Spaceguard Foundation which was carried out during the last 15 years mainly by the US with some modest European and amateur contributions. The number of known near Earth asteroids (NEAs) and potentially hazardous asteroids (PHAs) has increased tremendously, mainly thanks to five major surveys all focused on the discovery of new bodies. But also other facilities are required to follow-up and improvement the orbital parameters and to study the physical properties of the known bodies. These goals are better achieved by a co-ordinated network such as EURONEAR. Astrometry is mandatory in order to acquire the positional information necessary to define and improve orbits of NEAs and PHAs and to study their trajectories through the solar system, especially in the vicinity of Earth. Photometry is required to derive some physical information about NEAs and PHAs. In order to achieve these objectives, the main method of research of the EURONEAR is the follow-up programme of objects selected by a few criteria, carried out mostly at 1 m-class telescopes endowed with medium and large field cameras.
353. Near-Earth asteroids & QSOs close approaches
ID:
ivo://CDS.VizieR/J/A+A/509/A27
Title:
Near-Earth asteroids & QSOs close approaches
Short Name:
J/A+A/509/A27
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigated the link between the International Celestial Reference Frame (ICRF) and the dynamical reference frame realized by the ephemerides of the Solar System bodies. We propose a procedure that implies a selection of events for asteroids with accurately determined orbits crossing the CCD field containing selected quasars. Using a Bulirsch-Stoer numerical integrator, we constructed 8-years (2010-2018) ephemerides for a set of 836 numbered near-Earth asteroids (NEAs). We searched for close encounters (within a typical field of view of groundbased telescopes) between our selected set of asteroids and quasars with high-accuracy astrometric positions extracted from the Large Quasars Astrometric Catalog (LQAC). In the designated period (2010-2018), we found a number of 2924, 14257, and 6972 close approaches (within 10') between asteroids with a minimum solar elongation value of 60 degrees and quasars from the ICRF-Ext2, the Very Large Baseline Array Calibrator Survey (VLBA-CS), and the Very Large Array (VLA), respectively. This large number of close encounters provides the observational basis needed to investigate the link between the dynamical reference frame and the ICRF.
354. Near-IR astrometry of Southern ICRF quasars
ID:
ivo://CDS.VizieR/J/A+A/437/1135
Title:
Near-IR astrometry of Southern ICRF quasars
Short Name:
J/A+A/437/1135
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present high quality astrometry, along with J, H, and Ks photometry, for 30 southern International Celestial Reference Frame (ICRF) quasars observed with the ESO NTT/SOFI at La Silla. Our main purpose is to document the optical counterpart of ICRF quasars, by reporting their position in a stellar reference frame and their near-infrared photometry. Our investigation lies within the scope of extending the (radio) extragalactic reference frame into the optical range. An internal precision generally better than 10mas was obtained in positioning the near-infrared counterpart of these quasars within their stellar surroundings. The actual astrometric accuracy is estimated from the departure between the observed and the radio (VLBI) positions of quasars, and is about 35mas, mainly due to the statistical uncertainties of the stellar reference catalogue (UCAC2, Cat. <I/289>). The positional accuracy was improved to 25mas for a subset of 14 quasars observed with extended fields of view, as obtained from mosaics of overlapping images. The 3-band photometry was achieved with a precision most often better than 0.04mag, based on calibration with the 2MASS magnitudes.
355. Near-IR photometry in VVV CL08
ID:
ivo://CDS.VizieR/J/A+A/564/L9
Title:
Near-IR photometry in VVV CL08
Short Name:
J/A+A/564/L9
Date:
21 Oct 2021
Publisher:
CDS
Description:
Young massive clusters are key to map the Milky Way's structure, and near-IR large area sky surveys have contributed strongly to the discovery of new obscured massive stellar clusters. We present the third article in a series of papers focused on young and massive clusters discovered in the VVV survey. This article is dedicated to the physical characterization of VVV CL086, using part of its OB-stellar population. We physically characterized the cluster using JHKs near-infrared photometry from ESO public survey VVV images, using the VVV-SkZ pipeline, and near-infrared K-band spectroscopy, following the methodology presented in the first article of the series. Individual distances for two observed stars indicate that the cluster is located at the far edge of the Galactic bar. These stars, which are probable cluster members from the statistically field-star decontaminated CMD, have spectral types between O9 and B0V. According to our analysis, this young cluster (1.0Myr<age<5.0Myr) is located at a distance of 11kpc, and we estimate a lower limit for the cluster total mass of 2800 solar masses. It is likely that the cluster contains even earlier and more massive stars.
356. Neighborhoods of 36 loose groups of galaxies
ID:
ivo://CDS.VizieR/J/AJ/109/1458
Title:
Neighborhoods of 36 loose groups of galaxies
Short Name:
J/AJ/109/1458
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have selected 36 loose groups of galaxies from Ramella et al. 1989, with at least five members, and with mean redshift cz>3200km/s. These groups all lie within the first two "slices" of the CfA redshift survey <VII/164> (RA between 8h and 17h, DE between 2655.5 and 38.5 degrees). For each of these groups, we define the "redshift-space neighbourhood" as a region centered on the group coordinates and delimited by a circle of projected radius 1.5xh^-1^ Mpc on the sky, and by a velocity interval of 3000km/s. Table 2 lists the positions, magnitudes, radial velocities (cz) and their errors, for the members of the groups published in RGH89. Coordinates and magnitudes are from Zwicky's CGCG <VII/4>. Unpublished redshifts are marked with an asterisk in the last column. Table 3 lists galaxies within 1.5Mpc (assuming H0=100) and +/-1500 km/s from the centers of the groups in redshift space. Magnitudes and positions are from the Zwicky-Nielsen merged catalog. Some coordinates are better coordinates than Zwicky's, some come from compilations of redshift data that we have used to complement our measurements. Unpublished redshifts are marked with an asterisk in the last column. In this table some galaxies appear twice because a few groups do overlap. We listed the galaxies in common under the labels of both groups.
357. New candidate globular clusters in NGC 5128
ID:
ivo://CDS.VizieR/J/AJ/143/84
Title:
New candidate globular clusters in NGC 5128
Short Name:
J/AJ/143/84
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have used new wide-field imaging with the Magellan IMACS camera to search for globular cluster (GC) candidates around NGC 5128, the nearest giant E galaxy. The imaging data are in the B and R broadband filters and cover a 1.55 deg^2^ field centered on the galaxy, corresponding to an area about 90*90kpc^2^ at the distance of NGC 5128. All the fields were taken under exceptionally high-quality seeing conditions (FWHM=0.4-0.5" in R). Using this material we are able, for the first time in the literature, to construct a homogeneous list of GC candidates covering a wide span of the NGC 5128 halo and unusually free of field contaminants (foreground stars and faint background galaxies). Selecting the measured objects by color, magnitude, ellipticity, and profile size gives us a final catalog of 833 new high-quality GC candidates brighter than R=21 (0.8mag fainter than the standard GC luminosity function turnover point). The measured positions have better than 0.2" precision in both coordinates.
358. New members of Cygnus OB2 from Gaia DR2
ID:
ivo://CDS.VizieR/J/MNRAS/502/6080
Title:
New members of Cygnus OB2 from Gaia DR2
Short Name:
J/MNRAS/502/6080
Date:
21 Oct 2021
Publisher:
CDS
Description:
Due to the high quality of Gaia DR2 stellar parallaxes and proper motions, we can study the Cygnus OB2 region up to G=17.5mag in circular region centred at (l,b)=(79.8{deg},+0.8{deg}) of radius 1{deg}. We detect four over-densities in the Vector Point Diagram. We apply a parametric model of the proper motion distribution and determine their mean proper motions, identify their members and estimate their distances by analyzing the parallaxes of the most probable members. We confirm that one of these regions is Cygnus OB2, whose mean proper motion is (pmRA*cosDE,pmDE)=(-2.71+/-0.02,-4.24+/-0.02)mas/yr. We identify 2767 astrometric members at an estimated distance of 1683 {+/-} 5 pc. A detailed comparison of these members with 333 photometric and spectroscopic Cygnus OB2 members shows that 33 stars of the last group are not members, 16 of them are O-B stars. 300 members in common lead to estimate a distance to the association of 1669+/-6pc. One of the remaining over-densities is the open cluster UCB585 for which we find eight more members, located at ~1460pc. The other two groups count 179 and 188 proper motion members which are distributed throughout the region and situated at a distance of ~1280 pc. The estimated distances of these four groups suggest the existence of different substructures in the Cygnus OB2 region along the line of sight.
359. New Northern common proper-motion pairs
ID:
ivo://CDS.VizieR/J/MNRAS/355/585
Title:
New Northern common proper-motion pairs
Short Name:
J/MNRAS/355/585
Date:
21 Oct 2021
Publisher:
CDS
Description:
A list of 705 new Northern Celestial Hemisphere common proper motion pairs between 18 hours and 6 hours Right Ascension and 0 degrees and roughly 45 degrees Declination as derived from the Second U.S. Naval Observatory CCD Astrograph Catalog is presented, along with details of separation, motion, brightness and colour. This list is supplemented by a further 267 such pairs, derived in exactly the same way as the above 705 within the same Declination range, but for the region between 6 hours and 18 hours Right Ascension that was not included in the printed paper.
360. NEWS catalog
ID:
ivo://CDS.VizieR/J/A+A/644/A69
Title:
NEWS catalog
Short Name:
J/A+A/644/A69
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalogue of candidates in extragalactic objects -- the Northern Extragalactic WISExPan-STARRS (NEWS), which covers almost 3/4 of the sky in a broad optical-infrared spectral range, with a depth of up to 23mag in optical filter g. To create the NEWS catalogue, we used the mid-IR data of the WISE survey (W1,W2) paired up with photometric information of the Pan-STARRS DR1 survey in the optical and near-IR (g,r,i,z,y) spectral ranges. Our catalogue is the result of a classification of the WISExPan-STARRS objects with the SVM machine-learning algorithm. The classification was based solely on photometric information and the automatic creation of features that was carried out using an autoencoder neural network. NEWS catalogue contains 40,350,492 extragalactic objects (galaxies and quasars), identified with a high classification quality (>98%).

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