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311. Observations of Triton and Proteus
ID:
ivo://CDS.VizieR/J/A+A/425/1107
Title:
Observations of Triton and Proteus
Short Name:
J/A+A/425/1107
Date:
21 Oct 2021
Publisher:
CDS
Description:
Earth based observations of Proteus are made highly difficult by the magnitude difference with Neptune, and the closeness to the planet. To overcome these difficulties, observation campaigns using a Hg-mask coronograph developed for astrometry are being pursued at the Laboratorio Nacional de Astrofisica, Brazil. The observations are made at visible light wavelengths with the 1.6 m reflector telescope. The large 4'x4' field of view of the camera makes it possible to image a sufficient number of background stars that are used to carry out the astrometric analysis of these data. The first results of the campaigns are presented in this paper. They include 45 independent observations made over 2 nights in 2002. The positions are referred to the Hipparcos/Tycho2 (<I/239>/<I/259>)frame. The mean offsets relative to the JPL ephemeris are =0.083" ({sigma}=0.148") in the x={DELTA}RAcosDE direction, and -0.051" ({sigma}=0.115") in the y={DELTA}DE direction. Additional astrometric data need to be collected in order to investigate further the possible offset of Proteus with respect to the Voyager ephemerides.
312. OGLE General Catalog of Stars. I.
ID:
ivo://CDS.VizieR/I/244A
Title:
OGLE General Catalog of Stars. I.
Short Name:
I/244A
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper present the first part of the Optical Gravitational Lensing Experiment (OGLE) General Catalog of Stars in the Galactic Bulge. The catalog is based on observations collected during the OGLE microlensing search. This part contains 33196 stars brighter than I=18mag identified in the Baade's Window BWC field. Stars from remaining 20 OGLE fields will be presented in similar form in the next parts of the Catalog.
313. Open cluster properties with Gaia and LAMOST
ID:
ivo://CDS.VizieR/J/A+A/640/A127
Title:
Open cluster properties with Gaia and LAMOST
Short Name:
J/A+A/640/A127
Date:
01 Mar 2022 11:35:22
Publisher:
CDS
Description:
In Gaia DR2, an unprecedented high level of precision has been reached at sub-milliarcsecond for astrometry and millimagnitudes for photometry. Using cluster members identified with the astrometry and photometry in Gaia DR2, we can obtain a reliable determination of cluster properties. However, because of the shortcomings of Gaia spectroscopic observations in dealing with densely crowded cluster regions, the RVs and metallicity values for cluster member stars from Gaia DR2 are still lacking. It is necessary to combine the Gaia data with the data from large spectroscopic surveys, such as LAMOST, APOGEE, GALAH, and Gaia-ESO. In this study, we aim to improve the cluster properties by combining the LAMOST spectra. In particular, we provide the list of cluster members with spectroscopic parameters as an add-value catalog in LAMOST DR5, which can be used to perform detailed study for a better understanding on the stellar properties, by using their spectra and fundamental properties from the host cluster. We cross-matched the spectroscopic catalog in LAMOST DR5 (Luo et al., 2019, Cat. V/164) with the identified cluster members in Cantat-Gaudin et al. (2018, Cat. J/A+A/615/A49). We then used members with spectroscopic parameters to derive statistical properties of open clusters.We obtained a list of 8811 members with spectroscopic parameters and a catalog of 295 cluster properties. In addition, we study the radial and vertical metallicity gradient and age-metallicity relation with the compiled open clusters as tracers, finding slopes of -0.053+/-0.004dex/kpc, -0.252+/-0.039dex/kpc and 0.022+/-0.008dex/Gyr, respectively. Both slopes of metallicity distribution relation for young clusters (0.1Gyr<Age<2Gyr) and the age-metallicity relation for clusters within 6Gyr are consistent with literature results. In order to fully study the chemical evolution history in the disk, more spectroscopic observations for old and distant open clusters are needed for further investigation.
314. Open clusters near eta Car
ID:
ivo://CDS.VizieR/J/AJ/105/1822
Title:
Open clusters near eta Car
Short Name:
J/AJ/105/1822
Date:
21 Oct 2021
Publisher:
CDS
Description:
Proper motions and photographic photometry have been derived for nearly 600 stars with 7.5 < V < 15.5 in the region of the very young open clusters Tr 14, Tr 16, and Cr 232 based on 26 plates dating from 1893 to 1990. Cluster membership probabilities have been derived from the proper motions and color-magnitude diagrams of probable members of each cluster are presented. In contrast to a few of the previous studies we find all three clusters to lie at the same distance.
315. Optical coordinates of southern PNe
ID:
ivo://CDS.VizieR/J/other/RMxAA/37.115
Title:
Optical coordinates of southern PNe
Short Name:
J/other/RMxAA/37
Date:
21 Oct 2021
Publisher:
CDS
Description:
A homogeneous set of new measurements of nearly all (995 out of 1007) objects from the Strasbourg-ESO Catalogue of Galactic Planetary Nebulae (Cat. <V/100>) or in the first supplement of this catalogue in the area covered by the DENIS survey (<B/denis>) ({delta}<+2{deg}) is given here. A list of 24 new and 27 wrong cross-identifications with sources in the IRAS PSC catalogue and some confusion in the literature is listed as well.
316. Optical positions of ICRF sources
ID:
ivo://CDS.VizieR/J/AJ/125/2728
Title:
Optical positions of ICRF sources
Short Name:
J/AJ/125/2728
Date:
21 Oct 2021
Publisher:
CDS
Description:
New optical positions on the 30mas precision level have been obtained for 172 extragalactic International Celestial Reference Frame (ICRF) sources mainly in the range -30{deg}<=DE<=+25{deg}. Results are presented from a pilot investigation including four Cerro Tololo (CTIO) 0.9m runs (1999-2001). Reference stars in the R~10-16.5mag used. Systematic errors have been investigated, and a field distortion pattern based on the residuals has been removed. The errors of the fainter stars in the CTIO data were assessed by evaluating an auxiliary set of CCD observations of common ICRF sources, taken at the 1.60m Cassegrain telescope of the Laboratorio Nacional de Astrofisica, Brazil. A significant improvement in the optical positions was achieved over a previous determination of source positions. The mean optical positions are compared with the ICRF radio positions. The overall optical minus radio offsets are -6 and -15mas for right ascension and declination, respectively. The formal internal error of these mean offsets is ~2.3mas. his indicates a possible systematic error in the UCAC declinations of 10 to 15mas. Both the optical counterpart observations and the optical reference stars are observed about 9 yr after the Hipparcos mean epoch, and our results set an upper limit for a possible Hipparcos system rotation with respect to the International Celestial Reference System for the z-axis of about 0.7mas/yr.
317. Optical positions of radio emitting stars
ID:
ivo://CDS.VizieR/J/A+AS/117/335
Title:
Optical positions of radio emitting stars
Short Name:
J/A+AS/117/335
Date:
21 Oct 2021
Publisher:
CDS
Description:
In order to contribute to the alignment of the radio and optical reference frames, 50 stars with confirmed radio emission and published radio positions were observed by astrographical means. Additionally, two confirmed radio-stars of fainter magnitude were observed using a CCD direct camera with a long focus, large aperture telescope. The reductions are made relative to four catalogues: the Carlsberg Meridian Catalogue #4, the International Reference Stars Catalogue, the Positions and Proper Motion Catalogue and the Astrographical Catalogue of Reference Stars. The best results were obtained with the CAMC catalogue. The plate error of a radio star position is 0.07" for both right ascension and declination, rising to 0.10"-0.20" for bright stars. Ten of the program stars are not in the HIPPARCOS Input Catalogue and 12 do not belong to any of the major reference catalogues used. As soon as the HIPPARCOS results become available, its reference stars already measured in the plates will enable us to get positions for those 10 radio stars in the HIPPARCOS system.
318. Orbital parameters in Milky-Way-like potentials
ID:
ivo://CDS.VizieR/I/348
Title:
Orbital parameters in Milky-Way-like potentials
Short Name:
I/348
Date:
21 Oct 2021
Publisher:
CDS
Description:
Orbital parameters, such as eccentricity and maximum vertical excursion, of stars in the Milky Way are an important tool for understanding its dynamics and evolution, but calculation of such parameters usually relies on computationally-expensive numerical orbit integration. We present and test a fast method for estimating these parameters using an application of the Sackel fudge, used previously for the estimation of action-angle variables. We show that the method is highly accurate, to a level of <1% in eccentricity, over a large range of relevant orbits and in different Milky Way-like potentials, and demonstrate its validity by estimating the eccentricity distribution of the RAVE-TGAS data set and comparing it to that from orbit integration. Using the method, the orbital characteristics of the ~7 million Gaia DR2 stars with radial velocity measurements are computed with Monte Carlo sampled errors in ~116 hours of parallelised cpu time, at a speed that we estimate to be ~3 to 4 orders of magnitude faster than using numerical orbit integration. We demonstrate using this catalogue that Gaia DR2 samples a large range of orbits in the solar vicinity, down to those with r_peri_<~2.5kpc, and out to r_ap_>~13kpc. We also show that many of the features present in orbital parameter space have a low mean zmax, suggesting that they likely result from disk dynamical effects.
319. Orbits of spectro. binaries with CHARA Array. III.
ID:
ivo://CDS.VizieR/J/AJ/160/58
Title:
Orbits of spectro. binaries with CHARA Array. III.
Short Name:
J/AJ/160/58
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the visual orbits of two long-period spectroscopic binary stars, HD8374 and HD24546, using interferometric observations acquired with the Center for High Angular Resolution Astronomy (CHARA) Array and the Palomar Testbed Interferometer. We also obtained new radial velocities from echelle spectra using the APO 3.5m and Fairborn 2.0 telescopes. By combining the visual and spectroscopic observations, we solve for the full, three-dimensional orbits and determine the stellar masses and distances to within 3% uncertainty. We then estimate the effective temperature and radius of each component star through Doppler tomography and spectral energy distribution analyses, in order to compare the observed stellar parameters to the predictions of stellar evolution models. For HD8374, we find masses of M1=1.636{+/-}0.050M{sun} and M2=1.587{+/-}0.049M{sun}, radii of R1=1.84{+/-}0.05R{sun} and R2=1.66{+/-}0.12R{sun}, temperatures of Teff_1_=7280{+/-}110K and Teff-2-=7280{+/-}120K, and an estimated age of 1.0Gyr. For HD24546, we find masses of M1=1.434{+/-}0.014M{sun} and M2=1.409{+/-}0.014M{sun}, radii of R_1_=1.67{+/-}0.06R{sun} and R_2_=1.60{+/-}0.10R{sun}, temperatures of Teff_1_=6790{+/-}120K and Teff_2_=6770{+/-}90K, and an estimated age of 1.4Gyr. HD24546 is therefore too old to be a member of the Hyades cluster, despite its physical proximity to the group.
320. ORICAT Catalog of Stars in Orion Great Nebula
ID:
ivo://CDS.VizieR/J/AZh/88/143
Title:
ORICAT Catalog of Stars in Orion Great Nebula
Short Name:
J/AZh/88/143
Date:
21 Oct 2021
Publisher:
CDS
Description:
Six Tautenburg 2-m Schmidt telescope plates have been used to derive proper motions for 12740 stars down to Blim=18.5 in the region centered at RA=83.45grad, Dec=-5.20grad of the Great Nebula in Orion. Each plate covers a 3x3 grad region of sky, with a scale of 51.4"/mm. The largest difference between the epochs is 36 years. The photographic plates were scanned using Tautenburg Observatory plate scanner. The accuracy of the scans was 0.5micron, and the scale was 1000pixels/mm. The rectangular coordinates x, y and instrumental magnitudes were then determined using a dedicated software. To convert the scanned positions to the equatorial coordinates we adopt reference stars from the ACT catalog. Mean errors of position determinations are 3-4mas. The components of the proper motions and their rms uncertainties were obtained via linear least-squares fit to individual rectangular coordinates as a function of the observing epoch with no less than three epochs for every proper motion. The mean measurement uncertainty is 3.5mas/yr in magnitude interval 15-19 and 5.0mas/yr outside this interval. The photometry has been taken from Walker (1969) for B-magnitudes, and from USNO-A2.0 for R-magnitudes. Mean errors for photometry are 0.03mag in B and 0.25mag in R. The ORICAT is supplemented with the data of Parenago (1954) (stars with numbers greater 17000), and includes 13 577 stars in total. ACKNOWLEDGMENTS. We thank E. Schilbach, N.V. Kharchenko, and R.D. Scholz for numerous discussions of the results, and J. Brunzendorf and H. Meusinger for help in organizing the work at Jena Observatory.

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