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41. Astrometric catalog of Southern Dwarf Novae
ID:
ivo://CDS.VizieR/J/A+AS/93/463
Title:
Astrometric catalog of Southern Dwarf Novae
Short Name:
J/A+AS/93/463
Date:
21 Oct 2021
Publisher:
CDS
Description:
An astrometric catalog of 116 southern and equatorial dwarf novae is presented. The mean internal accuracy of the coordinates is of the order of +/- 0.025 s in alpha cos delta and +/- 0.3 arcsec in delta.
42. Astrometric Catalogue 5, LQAC-5
ID:
ivo://CDS.VizieR/J/A+A/624/A145
Title:
Astrometric Catalogue 5, LQAC-5
Short Name:
J/A+A/624/A145
Date:
21 Oct 2021
Publisher:
CDS
Description:
In addition to their great astrophysical interest, quasars represent quasi-ideal reference objects in the celestial sphere with, a priori, a lack of significant proper motion. Since the fourth release of the Large Quasar Astrometric Catalogue (LQAC-4), a large number of quasars have been discovered, in particular those coming from the DR14Q release of the SDSS. With the advent of the Gaia Data Release 2 (DR2), it is now also possible to fold in extremely accurate quasar positions. Following the same procedure as in the previous releases of the LQAC, our aim is to compile the large majority of the recorded quasars, with their best estimated coordinates and substantial information about their physical properties such as the redshift, multi-bands apparent, and absolute magnitudes. Emphasis is given to the results of the cross-matches with the Gaia DR2 catalogue, which considerably increases the positional accuracy. New quasars from the SDSS DR14Q release were cross-matched with the precedent LQAC-4 compilation with a 1" search radius, which leads to 149084 objects not present in the previous LQAC-4 release. Another cross-match was done with the Gaia DR2 catalogue, which enables us to considerably improve the positioning of these objects. For the first time, parallaxes and proper motions from the DR2, when available, are added to our compilation. Furthermore, a cross-identification of the LQAC-5 with the AllWISE survey gives additional mid-infrared information for an important percentage of objects. Our final catalogue, namely the LQAC-5, contains 592 809 quasars. This represents roughly a 34% increase with respect to the number of objects recorded in the LQAC-4. Among them, 398 697 objects were found in common with the Gaia DR2, within a 1" search radius. That corresponds to 67.26% of the whole population of the compilation. The LQAC-5 delivers a nearly complete catalogue of spectroscopically confirmed quasars (including a small proportion of 14126 compact AGN's) to the astronomical community, with the aim of giving their best equatorial coordinates with respect to the ICRF2 and with exhaustive additional information. For more than 50% of the sample, these coordinates are extracted from the very recent Gaia DR2.
43. Astrometric catalogue of stars KMAC3
ID:
ivo://CDS.VizieR/I/338
Title:
Astrometric catalogue of stars KMAC3
Short Name:
I/338
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results of astrometric observations of faint V<17mag stars obtained with the Kyiv meridian axial circle. Observations were carried out in 2010-2015 in a declination zone of +2 +5.5 degrees and with use of Johnson V-band filter. The catalogue contains data for about 2 million of stars.
44. Astrometric catalogue of stars KMAC2
ID:
ivo://CDS.VizieR/I/332
Title:
Astrometric catalogue of stars KMAC2
Short Name:
I/332
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results of astrometric observations of faint V<17mag stars obtained with the Kyiv meridian axial circle. Observations were carried out in 2001-2005 in a declination zone of 0+2 degrees and with use of Johnson V-band filter. The catalogue contains data for about a million of stars.
45. Astrometric classification of 647 VLBI sources
ID:
ivo://CDS.VizieR/J/A+A/618/A80
Title:
Astrometric classification of 647 VLBI sources
Short Name:
J/A+A/618/A80
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the result of our Allan standard deviation based classification according to their astrometric stability. The classification is divided into three categories (stable sources, intermediate sources, unstable sources). Stability of sources is qualified by the astrometric behavior of the source. This determines in which category the source falls into. Then, stability of the source is also quantified by a stability index (two are proposed in the table). Those indexes enable to order sources in each category of the classification.
46. Astrometric measurements of * bet LMi
ID:
ivo://CDS.VizieR/J/AJ/160/141
Title:
Astrometric measurements of * bet LMi
Short Name:
J/AJ/160/141
Date:
09 Mar 2022
Publisher:
CDS
Description:
bet LMi is a double-lined visual binary with an orbital period of ~39yr. Via a simultaneous fitting to both astrometric and radial velocity measurements, we give a complete and improved orbit solution with high precision. Then, the component masses are precisely determined as 2.98{+/-}0.10M{sun} and 1.92{+/-}0.04M{sun} with a relative precision of ~3%, respectively. The orbital parallax is determined to be 19.6{+/-}0.2mas, which is two times more precise than Hipparcos parallax. With the known apparent magnitudes and magnitude difference of the components, we derive the luminosity of the components as 50.7{+/-}1.8L{sun} and 9.1{+/-}4.1L{sun}. The estimated radii of the components are 9.4{+/-}0.3R{sun} and 3.7{+/-}1.5R{sun}.
47. Astrometric measurements of HD 143275
ID:
ivo://CDS.VizieR/J/ApJ/757/29
Title:
Astrometric measurements of HD 143275
Short Name:
J/ApJ/757/29
Date:
21 Oct 2021
Publisher:
CDS
Description:
The highly eccentric Be binary system {delta} Sco reached periastron during early 2011 July, when the distance between the primary and secondary was a few times the size of the primary disk in the H band. This opened a window of opportunity to study how the gaseous disks around Be stars respond to gravitational disturbance. We first refine the binary parameters with the best orbital phase coverage data from the Navy Precision Optical Interferometer. Then we present the first imaging results of the disk after the periastron, based on seven nights of five telescope observations with the MIRC combiner at the CHARA array. We found that the disk was inclined 27{deg}.6+/-6{deg}.0 from the plane of the sky, had a half-light radius of 0.49mas (2.2 stellar radii), and consistently contributed 71.4%+/-2.7% of the total flux in the H band from night to night, suggesting no ongoing transfer of material into the disk during the periastron. The new estimation of the periastron passage is UT 2011 July 3 07:00+/-4:30. Re-analysis of archival VLTI-AMBER interferometry data allowed us to determine the rotation direction of the primary disk, constraining it to be inclined either ~119{deg} or ~171{deg} relative to the orbital plane of the binary system. We also detect inner disk asymmetries that could be explained by spot-like emission with a few percent of the disk total flux moving in Keplerian orbits, although we lack sufficient angular resolution to be sure of this interpretation and cannot yet rule out spiral density waves or other more complicated geometries.
48. Astrometric observations of Deimos
ID:
ivo://CDS.VizieR/J/A+A/545/A144
Title:
Astrometric observations of Deimos
Short Name:
J/A+A/545/A144
Date:
21 Oct 2021
Publisher:
CDS
Description:
Between July 2005 and July 2011 Mars Express performed 50 Deimos approaches. 156 SRC images were acquired and used for astrometric (positional) measurements of the small Martian satellite. For this study, we have developed a new technique, where the center-of-figure of the odd-shaped Deimos was determined by fitting the predicted to the observed satellite limb. The prediction of the limb was made based on the moon's known shape model. The camera pointing was verified and corrected by means of background star observations. We obtained a set of spacecraft- centered Deimos coordinates with accuracies between 0.6 and 3.6km (1 sigma). Comparisons with current orbit models indicate that Deimos is ahead or falling behind its predicted position along its track by as much as +3.7km or -4.4km, respectively, depending on the chosen model. Our data may be used to improve the orbit models of the satellite.
49. Astrometric observations of Helene
ID:
ivo://CDS.VizieR/J/A+AS/143/405
Title:
Astrometric observations of Helene
Short Name:
J/A+AS/143/405
Date:
21 Oct 2021
Publisher:
CDS
Description:
Astrometric photographic positions of the Saturnian satellite Helene obtained from 22 plates taken in 6 nights are presented. The observations are distributed between 5 missions in 1985 and 1987. All positions are compared with those calculated by Jacobson (1999, personal communication). The residuals have mean and standard deviation smaller than 0.25" and 0.30" respectively.
50. Astrometric observations of Phobos
ID:
ivo://CDS.VizieR/J/A+A/580/A28
Title:
Astrometric observations of Phobos
Short Name:
J/A+A/580/A28
Date:
21 Oct 2021
Publisher:
CDS
Description:
Mars Express (MEX) carried out 74 Phobos flybys at distances between 669 and 5579km from April 2008 to August 2011. Images taken with the Super Resolution Channel (SRC) were used to determine the Martian moon's spacecraft-centered right ascension and declination. Image positions of Phobos were measured using the control point and limb fit measurement techniques. Camera pointing and pointing drift were controlled by means of background star observations that were compared to the corresponding positions from the Tycho-2 catalog. Blurred and noisy images were restored by applying an image-based point spread function in a Richardson-Lucy deconvolution. Altogether, we provide 158 astrometric observations of Phobos with estimated uncertainties between 0.224 and 3.405km circular about the direction to the satellite. Control point measurements yield more accurate results than limb fit observations.

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