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16411. Uranus & Neptune topocentric positions
ID:
ivo://CDS.VizieR/J/other/OAP/29.155
Title:
Uranus & Neptune topocentric positions
Short Name:
J/other/OAP/29.1
Date:
21 Oct 2021
Publisher:
CDS
Description:
Catalogs of 145 astrometric positions of Uranus and 4 its moons U1-U4 and 62 positions of Neptune and Triton have been compiled with Tycho-2 as a reference frame from photographic observations obtained at the Main Astronomical Observatory, National Academy of Sciences of Ukraine, in 1963-1990. Astronegatives have been digitized with an Epson Expression 10000XL commercial scanner in 16-bit grayscale with a resolution of 1200 dpi. Reduction has been performed in the LINUX-MIDAS-ROMAFOT software supplemented with additional modules for the precise positional determination. The internal positional accuracy of the reduction is 0.04-0.25" for both coordinates and 0.21-0.65m for photographic magnitudes of the Tycho-2 catalog. Gallery of plate images used for catalogs: http://gua.db.ukr-vo.org/catalog_gallery.php?catn=neptun_1963_1990 http://gua.db.ukr-vo.org/catalog_gallery.php?catn=uran_1963_1990
16412. URAT1 Catalog
ID:
ivo://CDS.VizieR/I/329
Title:
URAT1 Catalog
Short Name:
I/329
Date:
21 Oct 2021
Publisher:
CDS
Description:
URAT is a follow-up project to the successful UCAC project using the same astrograph but with a much larger focal plane array and a bandpass shifted further to the red. Longer integration times and more sensitive, backside CCDs allowed for a substantial increase in limiting magnitude, resulting in about 4-fold increase in the average number of stars per square degree as compared to UCAC. Additional observations with an objective grating largely extend the dynamic range to include observations of stars as bright as about 3rd magnitude. Multiple sky overlaps per year result in a significant improvement in positional precision as compared to UCAC. A URAT1 release paper for the Astronomical Journal is in preparation. URAT1 is an observational catalog at a mean epoch between 2012.3 and 2014.6; ot covers the magnitude range 3 to 18.5 in R-band, with a positional precision of 5 to 40 mas. It covers most of the northern hemisphere and some areas down to -24.8{deg} in declination.
16413. URAT Parallax Catalog (UPC)
ID:
ivo://CDS.VizieR/I/333
Title:
URAT Parallax Catalog (UPC)
Short Name:
I/333
Date:
21 Oct 2021
Publisher:
CDS
Description:
The URAT Parallax Catalog (UPC) consists of 112177 parallaxes. The catalog utilizes all Northern Hemisphere epoch data from the United States Naval Observatory (USNO) Robotic Astrometric Telescope (URAT). This data includes all individual exposures from April 2012 to June 2015 giving a larger epoch baseline for determining parallaxes over the 2-year span of the First USNO Robotic Astrometric Telescope Catalog (URAT1) (Zacharias et al., 2015, Cat. I/329) published data. The URAT parallax pipeline is custom code that utilizes routines from (Jao, C.-W., 2004, PhD thesis Georgia Stat), the JPL DE405 ephemeris and Green's parallax factor (Green, R.M., 1985, Spherical Astronomy) for determining parallaxes from a weighted least-squares reduction. The relative parallaxes have been corrected to absolute by using the distance color relation described in (Finch et. al, 2014, Cat. J/AJ/148/119) to determine a mean distance of all UCAC4 reference stars (R=8-16 mag) used in the astrometric reductions. Presented here are all significant parallaxes from the URAT Northern Hemisphere epoch data comprising of 2 groups: a) URAT parallax results for stars with prior published parallax, and b) first time trigonometric parallaxes as obtained from URAT data of stars without prior published parallax. Note, more stringent selection criteria have been applied to the second group than the first in order to keep the rate of false detections low. For specific information about the astrometric reductions please see 'The First U.S. Naval Observatory Robotic Astrometric Telescope Catalog' published paper (Zacharias et al., 2015AJ....150..101Z, Cat. I/329). For complete details regarding the parallax pipeline please see 'Parallax Results From URAT Epoch Data' (Finch and Zacharias, 2016, AJ, in press). This catalog gives all positions on the ICRS at Epoch J2014.0; it covers the magnitude range 6.56 to 16.93 in the URAT band-pass, with an average parallax precision of 4.3mas for stars having no known parallax and 10.8mas for stars matched to external parallax sources. This catalog covers the sky from about North of -12.75{deg} declination. This catalog was matched with the Hipparcos catalog, Yale Parallax Catalog, (Finch & Zacharias, 2016, AJ, in press), MEarth (Dittmann et. al., 2014ApJ...784..156D) and the SIMBAD database to obtain known parallax and star names. For stars matched to SIMBAD using the automated search feature, only the parallaxes are given so no information on the parallax errors or source for the parallax are reported for those stars in this catalog. A flag is included to show which catalog or database the URAT parallax was matched with. Only the data from the first catalog that was matched is reported here according to the following priority list. This means for example, if a star was matched with Hipparcos, that information was used while possible other catalog data are not listed here. -------------------------------------------------------- # stars flg catalog -------------------------------------------------------- 53500 0 no catalog match 55549 1 Hipparcos 254 2 Yale Parallax Catalog 1041 3 Finch and Zacharias 2016 (UPM NNNN-NNNN) 1431 4 MEarth parallaxes 402 5 SIMBAD Database (w/parallax) -------------------------------------------------------- 112177 total number stars in catalog -------------------------------------------------------- Not all parallaxes from the URAT epoch data are included in this catalog. Only those data meeting the following criteria have been included. For the epoch data we only used data having a FWHM<=7.0pixel; amplitude between 500 and 30000ADU; sigma x,y <=90.0mas; number of observations >=20 and epoch span>=1.0 years. The limits imposed on individual image amplitude, image profile width (FWHM) and position fit errors (sigma) are set to not allow saturated stars, stars with too few photons or poorly determined positions to be used in the parallax solution. We present all URAT parallax solutions having a known parallax from an external data source regardless of the quality of the solution (srcflg=1-5). This was done for the user to better understand the limitations for determining parallaxes with the current URAT epoch data. For the remaining URAT parallaxes without a match to any published trigonometric parallax (srcflg=0) we only present a parallax solutions having: 1) a parallax error <=10mas 2) a parallax error <=1/4 the relative parallax 3) epoch span >=1.5 years 4) number of observations used >=30 5) fit sigma<=1.4 (unit weight) 6) average image elongation <1.1. All of these cuts have been implemented in an attempt to lower the number of possible erroneous parallax solutions entering our catalog. However, the URAT reduction process does not take provisions for close doubles (blended images) of arcsecond-level separations. Many of the parallaxes, particularly those with large mean elongation, large parallax error, large fit sigma and many rejected observations are possibly blended images leading to a higher chance of an erroneous parallax solutions. A visual inspection of all residual plots and real sky images would not be practical for the entire catalog. However, we have included information in the catalog to help the user to determine if a solution should be investigated further.
16414. UrHip Proper Motion Catalog
ID:
ivo://CDS.VizieR/J/AJ/150/141
Title:
UrHip Proper Motion Catalog
Short Name:
J/AJ/150/141
Date:
21 Oct 2021
Publisher:
CDS
Description:
Proper motions are computed and collected in a catalog using the Hipparcos positions (epoch 1991.25) and URAT1 positions (epoch 2012.3 to 2014.6). The goal is to obtain a significant improvement on the proper motion accuracy of single stars in the northern hemisphere, and to identify new astrometric binaries perturbed by orbital motion. For binaries and multiple systems, the longer baseline of Tycho2 (~100yr) makes it more reliable despite its larger formal uncertainties. The resulting proper motions obtained for 67340 stars have a consequent gain in accuracy by a factor of ~3 compared to Hipparcos. Comparison between UrHip and Hipparcos shows that they are reasonably close, but also reveals stars with large discrepant proper motions, a fraction of which are potential binary candidates.
16415. Ursa Minor dSph M,T2, DDO51 photometry
ID:
ivo://CDS.VizieR/J/AJ/125/1352
Title:
Ursa Minor dSph M,T2, DDO51 photometry
Short Name:
J/AJ/125/1352
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a large-area photometric survey of the Ursa Minor dwarf spheroidal galaxy and its environs. This survey is intended to trace the distribution of stars outside the nominal tidal radius of this system. Observations were made with the Washington M, Washington T2, and DDO51 filters, which in combination have been shown to provide reliable stellar luminosity classification for K-type stars.
16416. USco ZYJHK1K2 photometry and proper motions
ID:
ivo://CDS.VizieR/J/MNRAS/435/2474
Title:
USco ZYJHK1K2 photometry and proper motions
Short Name:
J/MNRAS/435/2474
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of a deep ZYJ near-infrared survey of 13.5deg^2^ in the Upper Scorpius (USco) OB association. We photometrically selected ~100 cluster member candidates with masses in the range of 30-5 Jupiters, according to state-of-the-art evolutionary models. We identified 67 ZYJ candidates as bona fide members, based on complementary photometry and astrometry. We also extracted five candidates detected with Visible and Infrared Survey Telescope for Astronomy at YJ only. One is excluded using deep optical z-band imaging, while two are likely non-members, and three remain as potential members. We conclude that the USco mass function is more likely decreasing in the planetary-mass regime (although a flat mass function cannot yet be discarded), consistent with surveys in other regions.
16417. Using H-bump to identify RSGs in NGC6822
ID:
ivo://CDS.VizieR/J/A+A/647/A167
Title:
Using H-bump to identify RSGs in NGC6822
Short Name:
J/A+A/647/A167
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a case study in which we used a novel method to identify red supergiant (RSG) candidates in NGC 6822 based on their 1.6um H-bump. We collected 32 bands of photometric data for NGC 6822 ranging from the optical to the mid-infrared (MIR), derived from Gaia, PS1, LGGS, VHS, UKIRT, IRSF, HAWK-I, Spitzer, and WISE. Using the theoretical spectra from MARCS, we demonstrate that there is a prominent difference around 1.6um (H-bump) between targets with high and low surface gravity (HSG and LSG). Taking advantage of this feature, we identify efficient color-color diagrams of rzH (r-z versus z-H) and rzK (r-z versus z-K) to separate HSG (mostly foreground dwarfs) and LSG targets (mainly background red giant stars, asymptotic giant branch stars, and RSGs) from crossmatching of optical and near-infrared (NIR) data. Moreover, synthetic photometry from ATLAS9 gives similar results. We further separated RSG candidates from the remaining LSG candidates as determined by the H-bump method by using semi-empirical criteria on NIR color-magnitude diagrams, where both the theoretic cuts and morphology of the RSG population are considered. This separation produced 323 RSG candidates. The simulation of foreground stars with Besancon models also indicates that our selection criteria are largely free from the contamination of Galactic giants. In addition to the H-bump method, we used the traditional BVR method (B-V versus V-R) as a comparison and/or supplement by applying a slightly aggressive cut to select as many RSG candidates as possible (358 targets). Furthermore, the Gaia astrometric solution was used to constrain the sample, where 181 and 193 targets were selected with the H-bump and BVR method, respectively. The percentages of selected targets in the two methods are similar at ~60%, indicating a comparable accuracy of the two methods. In total, there are 234 RSG candidates after combining targets from the two methods, and 140 (~60%) of them are in common. The final RSG candidates are in the expected locations on the mid-infrared color-magnitude diagram with [3.6]-[4.5]<~0 and J-[8.0]~1.0. The spatial distribution is also coincident with the far-ultraviolet-selected star formation regions, suggesting that the selection is reasonable and reliable. We indicate that our method can also be used to identify other LSG targets, such as red giants and asymptotic giant branch stars, and it can also be applied to most of the nearby galaxies by using recent large-scale ground-based surveys. Future ground- and space-based facilities may promote its application beyond the Local Group.
16418. US Naval Observatory Pleiades Catalog
ID:
ivo://CDS.VizieR/I/163
Title:
US Naval Observatory Pleiades Catalog
Short Name:
I/163
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalog is a special subset of the Eichhorn et al. (1970) Pleiades catalog (see <I/90>) updated to B1950.0 positions and with proper motions added. It was prepared for the purpose of predicting occultations of Pleiades stars by the Moon, but is useful for general applications because it contains many faint stars not present in the current series of large astrometric catalogs.
16419. U.S. Naval Observatory Zodiacal Zone Catalog
ID:
ivo://CDS.VizieR/I/157
Title:
U.S. Naval Observatory Zodiacal Zone Catalog
Short Name:
I/157
Date:
21 Oct 2021
Publisher:
CDS
Description:
The catalog provides positions and proper motions at equinox and epoch J2000.0, on the FK5 system, for stars in the magnitude range 4-10, lying within 16 degrees of the ecliptic and north of declination -30 degrees. In order that references to earlier catalogs can be made, the B1950.0 positions and proper motions are given in both the FK5 and the FK4 systems. Other useful information, such as visual magnitudes and spectral types, is also provided. Stellar identification is strictly by Durchmusterung number, and the catalog is ordered by J2000.0 right ascension. It is important to understand that the present catalog does not cover the entire zodiacal zone, since stars south of zone -29 degrees could not be observed from the Washington site. These will be observed from the USNO Black Birch station in New Zealand commencing in 1991.
16420. USNO-A2 Catalogue
ID:
ivo://fs.usno/cat/usnoa2
Title:
USNO-A2 Catalogue
Short Name:
USNO-A2
Date:
03 Feb 2020 22:20:44
Publisher:
United States Naval Observatory, Flagstaff Station
Description:
USNO-A2.0 is a catalog of 526,280,881 stars, and is based on a re-reduction of the Precision Measuring Machine (PMM) scans that were the basis for the USNO-A1.0 catalog. The major difference between A2.0 and A1.0 is that A1.0 used the Guide Star Catalog (Lasker et al. 1986, see Cat. &lt;I/220&gt;) as its reference frame whereas A2.0 uses the ICRF as realized by the USNO ACT catalog (Urban et al. 1997, see Cat. II/246&gt;). A2.0 presents right ascension and declination (J2000, epoch of the mean of the blue and red plate) and the blue and red magnitude for each star. Usage of the ACT catalog as well as usage of new astrometric and photometric reduction algorithms should provide improved astrometry (mostly in the reduction of systematic errors) and improved photometry (because the brightest stars on each plate had B and V magnitudes measured by the Tycho experiment on the Hipparcos satellite). The basic format of the catalog and its compilation is the same as for A1.0, and most users should be able to migrate to this newer version with minimal effort. (1 data file).

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