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531. Solar neighborhood. XXXIX. Nearby white dwarfs
ID:
ivo://CDS.VizieR/J/AJ/154/32
Title:
Solar neighborhood. XXXIX. Nearby white dwarfs
Short Name:
J/AJ/154/32
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present 114 trigonometric parallaxes for 107 nearby white dwarf (WD) systems from both the Cerro Tololo Inter-American Observatory Parallax Investigation (CTIOPI) and the U. S. Naval Observatory Flagstaff Station (NOFS) parallax programs. Of these, 76 parallaxes for 69 systems were measured by the CTIOPI program and 38 parallaxes for as many systems were measured by the NOFS program. A total of 50 systems are confirmed to be within the 25-pc horizon of interest. Coupled with a spectroscopic confirmation of a common proper-motion companion to a Hipparcos star within 25pc as well as confirmation parallax determinations for two WD systems included in the recently released Tycho Gaia Astrometric Solution catalog, we add 53 new systems to the 25-pc WD sample-a 42% increase. Our sample presented here includes four strong candidate halo systems, a new metal-rich DAZ WD, a confirmation of a recently discovered nearby short-period (P=2.85hr) double degenerate, a WD with a new astrometric perturbation (long period, unconstrained with our data), and a new triple system where the WD companion main-sequence star has an astrometric perturbation (P~1.6year).
532. Sou323 ICRF reference sample
ID:
ivo://CDS.VizieR/J/MNRAS/466/1567
Title:
Sou323 ICRF reference sample
Short Name:
J/MNRAS/466/1567
Date:
21 Oct 2021
Publisher:
CDS
Description:
We aim to evaluate the possibility of improving the International Celestial Reference System realization starting from the ICRF2 catalogue by investigating the coordinate time series of radio sources observed by the very long baseline interferometry between 1979 and 2016. Sources with long observational history are selected as the candidates and the least-squares fits with special handling of the weights are performed to derive the linear drifts of the source coordinates. Then the sources are sorted, based on the normalized linear drift (i) over the whole sky, and (ii) in four homolographic areas divided by declinations. The axial stability of the reference system and sky distribution defined by the selected sources are evaluated, which are acted as the criterion for the final source lists. With our improved source selection scheme, two groups of sources are proposed and considered suitable for defining a more stable and homogeneous celestial reference system compared to the second version of the current International Celestial Reference Frame (ICRF2). The number of sources in the final lists are 323 and 294, respectively, and the global rotations of the axes derived from apparent motion of the sources are about two times better th
533. Southern Hemisphere Catalogue of Bordeaux
ID:
ivo://CDS.VizieR/I/230
Title:
Southern Hemisphere Catalogue of Bordeaux
Short Name:
I/230
Date:
21 Oct 2021
Publisher:
CDS
Description:
As part of the preparation for the Hipparcos mission, we determined the positions of 96800 already listed stars and 21265 previously unlisted companions, using information gathered by the ESO Quick Blue Survey. B1950 and J2000 system coordinates are given for each star. The magnitudes and spectral types are given in addition to the exact date of the observation (approximately 1976). PPM, HIC, SAO, HD, CoD, CPD, CPC, ADS, IDS, BD, LHS and V* identifiers are given systematically whenever they exist as well as two supplementary identifiers selected from 43 other catalogues. Comments were added when necessary to complete the information.
534. Southern high proper motion stars positions
ID:
ivo://CDS.VizieR/J/A+AS/124/437
Title:
Southern high proper motion stars positions
Short Name:
J/A+AS/124/437
Date:
21 Oct 2021
Publisher:
CDS
Description:
Several stars with large proper motions, cited by W.J. Luyten, were included in the preliminary programme for the HIPPARCOS mission. When performing preparatory measurements of plates, difficulties were encountered in identifying certain of these stars when relying only on published coordinates. We have taken advantage of this work which relates to the southern sky in order to determine the astrometric position of the greatest possible number of these objects, even for those which were not included in the programme.
535. Southern Infrared Proper Motion Survey
ID:
ivo://CDS.VizieR/J/A+A/435/363
Title:
Southern Infrared Proper Motion Survey
Short Name:
J/A+A/435/363
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the first results from the Southern Infrared Proper Motion Survey. Using 2 Micron All Sky Survey (<II/246>) data along with that of the SuperCOSMOS sky survey (Hambly et al., 2001MNRAS.326.1279H) we have been able to produce the first widefield infrared proper motion survey. Having targeted the survey to identify nearby M, L and T dwarfs we have discovered 70 such new objects with proper motions greater than 0.5"/yr with 10 of these having proper motions in excess of 1"/yr.
536. Southern methanol masers at 36 and 44GHz
ID:
ivo://CDS.VizieR/J/MNRAS/439/2584
Title:
Southern methanol masers at 36 and 44GHz
Short Name:
J/MNRAS/439/2584
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Australia Telescope Compact Array (ATCA) has been used for high angular resolution imaging of 71 southern class I methanol maser sources quasi-simultaneously at 36 and 44GHz. The data reveal a high level of morphological and kinematical complexity, and allow us to demonstrate associations, at arcsecond precision, of the class I maser emission with outflows, expanding HII regions, dark clouds, shocks traced by the 4.5-micron emission and 8.0-micron filaments. More than 700 maser component features were found at each of the two methanol transitions, but with only 23 per cent recognisable at both transitions; the morphology of class I emission is much better revealed by our survey of both transitions, compared with either one alone. We found that the number of masers falls exponentially with the projected linear distance from the associated class II 6.7-GHz methanol maser. This distribution has a scale of 263+/-15-milliparsec, irrespective of the transition. The class I masers associated with OH masers were found to have a tendency to be more spread out, both spatially and in the velocity domain. This is consistent with the expectation that such sources are more evolved. Apart from a small number of high-velocity components (which are largely blue-shifted and predominantly seen at 36GHz), the velocity distribution was found to be Gaussian, peaking near the systemic velocity of the region, which had been estimated as the middle of the velocity interval of the associated class II methanol maser at 6.7GHz. The mean indicated a small, but significant blue shift asymmetry of -0.57km/s (uncertainties are 0.06 and 0.07km/s for the 36- and 44-GHz masers, respectively) with respect to the 6.7GHz masers. The standard deviation of the velocity distribution was found to be 3.65+/-0.05 and 3.32+/-0.07km/s for the 36- and 44GHz masers, respectively. We also suggest a refined rest frequency value of 36169.238+/-0.011MHz for the 4_-1_-3_0_E methanol transition.
537. Southern Reference Star Catalogue
ID:
ivo://CDS.VizieR/I/138
Title:
Southern Reference Star Catalogue
Short Name:
I/138
Date:
21 Oct 2021
Publisher:
CDS
Description:
The positions are the combined results of observations of all participants in the Southern Reference Star (SRS) observing campaign from 1961 tO 1973. Preliminary catalogs were compiled at both the U.S. Naval Observatory (Washington) and the Pulkovo Observatory (Leningrad). The two compilations were compared, reconciled and combined to give the catalog described here. The proper motions have been culled from a number of different sources and should not be regarded as part of the SRS observed catalog. The proper motions are given principally as a means to take into account the small differences in epoch of observation between the SRS and the 2nd Cape Photographic Catalog plate material, which is at most about two years. Because of the inhomogeneous nature of the proper-motion sources and the likely presence of magnitude related systematic errors in the proper motions, they may not safely be used to extend the SRS system of positions very far from the mean epoch of observation which is about 1968. A discussion by T. Corbin of all the SRS observations including those made before and after the 1961 to 1973 campaign and their reduction to the FK4 system is at an advanced stage of preparation and will yield the desired high quality proper motions required for transferring the system to more distant epochs. Two sets of positions and proper motions are given. One set is referred to the equator and equinox of B1950.0 and the other to the equator and equinox of J2000.0. The positions are referred to the mean epoch of observation in both cases. The B1950.0 positions were linked directly to the system of FK4 by observational techniques. The J2000.0 data are based on a transformation of the B1950.0 data. The transformation was accomplished in two steps. First, FK5-FK4 differences referred to the B1950.0/FK4 system were added to the SRS positions and proper motions. The FK5-FK4 differences are those given by the analytical coefficients of H. Schwan (Astronomisches Rechen-Institut, Heidelberg). Second, the reduction from B1950.0 to J2000.0 was accomplished by using the conversion procedure described in the 1988 edition of THE ASTRONOMICAL ALMANAC (pg. B42). The (FK5-FK4) differences are given along with the average FK4 magnitude used as the input argument to Schwan's subroutines. An average FK4 magnitude was estimated for each SRS position from the average magnitude of all FK4 stars in an area on the celestial sphere bounded by a four-hour interval in right ascension and a 20-degree interval in declination centered on the SRS. All SRS less than 10 deg from the pole were treated as if they had been at -80 deg declination for the calculation of the average FK4 magnitude only. This transformation procedure gives a first order reduction from the FK4 to the FK5 system. A more precise reduction of many of the SRS catalogs observed from 1961 to 1973 is possible from a re-discussion of the FK4 star observations made concurrently with the SRS observations on a nightly basis. A program to reduce first the SRS and then the AGK3R to the FK5 system as directly as possible, going back to the nightly observations of FK4/FK5 when they are available, is now in progress at the observatory in Washington.
538. 5969 Southern Reference Stars and 726 Bright stars
ID:
ivo://CDS.VizieR/I/309
Title:
5969 Southern Reference Stars and 726 Bright stars
Short Name:
I/309
Date:
21 Oct 2021
Publisher:
CDS
Description:
The catalogue contains 5969 southern reference stars (SRS) and 726 bright stars (BS). The observations were carried out in the declination zone from 0{deg} to -20{deg} with the Repsold meridian circle in Nikolaev Astronomical Observatory (Ukraine) in 1964-1966. The RMS errors of right ascensions are 18ms and 25ms for the SRS and the BS correspondingly. The RMS errors of declinations are 480mas and 470mas for the SRS and the BS correspondingly. The catalogue is in good agreement with a system of the FK4.
539. Spatially offset AGN cand. in CLASS survey
ID:
ivo://CDS.VizieR/J/MNRAS/475/5179
Title:
Spatially offset AGN cand. in CLASS survey
Short Name:
J/MNRAS/475/5179
Date:
02 Nov 2021 11:24:39
Publisher:
CDS
Description:
Prompted by a recent claim by Barrows et al. that X-ray active galactic nuclei (AGNs) are often found significantly offset from the centres of their host galaxies, we have looked for examples of compact radio sources that are offset from the optical centroids of nearby (z<0.2) galaxies. We have selected a sample of 345 galaxies from the Sloan Digital Sky Survey (SDSS) galaxy catalogue, which have nearby compact radio sources listed in the Cosmic-Lens All Sky Survey (CLASS) catalogue. We find only three matches ~0.87 per cent of the sample) with offsets greater than 600 milliarcsec (mas), which is considerably fewer than we would have expected from the Barrows et al. X-ray survey. We fit our histogram of offsets with a Rayleigh distribution with {sigma}=60.5mas, but find that there is an excess of objects with separations greater than ~150mas. Assuming that this excess represents AGNs with real offsets, we place an upper limit of ~17 per cent on the fraction of offset AGNs in our radio-selected sample. We select 38 objects with offsets greater than 150mas, and find they have some diverse properties: Some are well known, such as Mrk 273 and Arp 220, some have dust lanes, which may have affected the optical astrometry, and a few are strong new candidates for offset AGNs.
540. Speckle interferometry at SOAR in 2020
ID:
ivo://CDS.VizieR/J/AJ/162/41
Title:
Speckle interferometry at SOAR in 2020
Short Name:
J/AJ/162/41
Date:
14 Mar 2022 06:54:42
Publisher:
CDS
Description:
The results of speckle interferometric observations at the 4.1m Southern Astrophysical Research Telescope in 2020, as well as earlier unpublished data, are given, totaling 1735 measurements of 1288 resolved pairs and nonresolutions of 1177 targets. We resolved for the first time 59 new pairs or subsystems in known binaries, mostly among nearby dwarf stars. This work continues our long-term speckle program. Its main goal is to monitor orbital motion of close binaries, including members of high-order hierarchies and Hipparcos pairs in the solar neighborhood. We also report observations of 892 members of young moving groups and associations, where we resolved 103 new pairs.

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