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271. Mars Express astrometric obs. of Martian moons
ID:
ivo://CDS.VizieR/J/A+A/614/A15
Title:
Mars Express astrometric obs. of Martian moons
Short Name:
J/A+A/614/A15
Date:
21 Oct 2021
Publisher:
CDS
Description:
Both Martian moons, Phobos and Deimos, have been observed during several imaging campaigns by the SRC on Mars Express. Several tens of images are obtained during mutual event observations - when the Martian moons are both observed or together with another solar system body. These observations provide new opportunities to determine the bodies' positions in their orbits. A method was sought to automate the observation of the positions of the imaged bodies. Within one image sequence a similarly accurate localization of the objects in all images should be possible. Shape models of Phobos and Deimos are applied to simulate the appearance of the bodies in the images. Matching the illuminated simulation against the observation provides a reliable determination of the bodies' location within the image. To enhance the matching confidence several corrections need to be applied to the simulation to closely reconstruct the observation. In total 884 relative positions between the different objects are provided.
272. Mass determination using microlensing by Gaia
ID:
ivo://CDS.VizieR/J/A+A/640/A83
Title:
Mass determination using microlensing by Gaia
Short Name:
J/A+A/640/A83
Date:
15 Dec 2021 08:30:09
Publisher:
CDS
Description:
Astrometric gravitational microlensing can be used to determine the mass of a single star (the lens) with an accuracy of a few percent. To do so, precise measurements of the angular separations between lens and background star with an accuracy below 1 milli-arcsecond at different epochs are needed. Therefore only the most accurate instruments can be used. However, since the timescale is on the order of months to years, the astrometric deflection might be detected by Gaia, even though each star is only observed on a low cadence. We want to show how accurately Gaia can determine the mass of the lensing star. Using conservative assumptions based on the results of the second Gaia data release (GaiaDR2), we simulated the individual Gaia measurements for 501 predicted astrometric microlensing events during the Gaia era (2014.5 - 2026.5). For this purpose we used the astrometric parameters of Gaia DR2, as well as an approximative mass based on the absolute G magnitude. By fitting the motion of the lens and source simultaneously, we then reconstructed the 11 parameters of the lensing event. For lenses passing by multiple background sources, we also fitted the motion of all background sources and the lens simultaneously. Using a Monte-Carlo simulation we determined the achievable precision of the mass determination. We find that Gaia can detect the astrometric deflection for 114 events. Furthermore, for 13 events Gaia can determine the mass of the lens with a precision better than 15% and for 13 + 21 = 34 events with a precision of 30% or better.
273. 2MASS J18212815+1414010 field stars
ID:
ivo://CDS.VizieR/J/MNRAS/455/357
Title:
2MASS J18212815+1414010 field stars
Short Name:
J/MNRAS/455/357
Date:
21 Oct 2021
Publisher:
CDS
Description:
We used the OSIRIS camera at the 10.4m Gran Telescopio Canarias (GTC) to monitor the astrometric motion of the L4.5 dwarf 2M1821+14 over 17 months. The astrometric residuals of 11 epochs have an rms dispersion of 0.4mas, which is larger than the average precision of 0.23mas per epoch and hints towards an additional signal or excess noise. Comparison of the point-spread functions in OSIRIS and FORS2/VLT images reveals no differences critical for high-precision astrometry, despite the GTC's segmented primary mirror. We attribute the excess noise to an unknown effect that may be uncovered with additional data. For 2M1821+14, we measured a relative parallax of 10^6.15^+/-0.18mas and determined a correction of 0.50+/-0.05mas to absolute parallax, leading to a distance of 9.38+/-0.03pc. We excluded at 3{sigma} confidence the presence of a companion to 2M1821+14 down to a mass ratio of 0.1 (~5M_Jupiter_) with a period of 50-1000d and a separation of 0.1-0.7au. The accurate parallax allowed us to estimate the age and mass of 2M1821+14 of 120-700Myr and 0.049^+0.014^_-0.024_M_{sun}_, thus confirming its intermediate age and substellar mass. We complement our study with a parallax and proper motion catalogue of 587 stars (i'=~15.5-22) close to 2M1821+14, used as astrometric references. This study demonstrates submas astrometry with the GTC, a capability applicable for a variety of science cases including the search for extrasolar planets and relevant for future astrometric observations with E-ELT and TMT.
274. Mass-luminosity relation
ID:
ivo://CDS.VizieR/J/AJ/106/773
Title:
Mass-luminosity relation
Short Name:
J/AJ/106/773
Date:
21 Oct 2021
Publisher:
CDS
Description:
Mass-luminosity relations determined at infrared wavelengths are presented for stars with masses 1.0 to 0.08 solar masses. Using infrared speckle imaging techniques on a sample of nearby binaries, we have been able to concentrate on the lower main sequence (Mass<=0.5M_sun_), for which an accurate mass-luminosity calibration has remained problematic. In addition, the mass-visual luminosity relation for stars with 2.0>=Mass>=0.08M_sun_ is produced by implementing new photometric relations linking V to JHK wavelengths for the nearby stars, supplemented with eclipsing binary information. These relations predict that objects with masses ~0.08 solar masses have M(K)~=10 and M(V)~=18.
275. 2Mass Query
ID:
ivo://org.gavo.dc/2mass/res/2mass/q
Title:
2Mass Query
Short Name:
twomass_q
Date:
27 Dec 2024 08:31:04
Publisher:
The GAVO DC team
Description:
The 2MASS Point Source Catalogue, short a couple of exotic fields. We provide this data mainly for matching with other catalogs within our TAP service.
276. M2000: Bordeaux Carte du Ciel zone +11<Dec<+18
ID:
ivo://CDS.VizieR/I/272
Title:
M2000: Bordeaux Carte du Ciel zone +11<Dec<+18
Short Name:
I/272
Date:
21 Oct 2021
Publisher:
CDS
Description:
During four years, systematic observations have been conducted in drift scan mode with the Bordeaux automated meridian circle in the declination band [+11 ; +18]. The resulting astrometric catalog includes about 2 300 000 stars down to the magnitude limit V_M_=16.3. Nearly all stars (96%) have been observed at least 6 times, the catalog being complete down to V_M_=15.4. The median internal standard error in position is about 35mas in the magnitude range 11<V_M_<15, which degrades to about 50mas when the faintest stars are considered. M2000 provides also one band photometry with a median internal standard error of 0.04mag. Comparisons with the Hipparcos and bright part of Tycho-2 catalogs have enabled to estimate external errors in position to be lower than 40mas. In this zone and at epoch 1998, the faint part of Tycho-2 is found to have an accuracy of 116mas in alpha instead of 82mas deduced from the model-based standard errors given in the catalog.
277. MCXC Meta-Catalogue X-ray galaxy Clusters
ID:
ivo://CDS.VizieR/J/A+A/534/A109
Title:
MCXC Meta-Catalogue X-ray galaxy Clusters
Short Name:
J/A+A/534/A109
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the compilation and properties of a meta-catalogue of X-ray detected clusters of galaxies, the MCXC. This very large catalogue is based on publicly available ROSAT All Sky Survey-based (NORAS, REFLEX, BCS, SGP, NEP, MACS, and CIZA) and serendipitous (160SD, 400SD, SHARC, WARPS, and EMSS) cluster catalogues. Data have been systematically homogenised to an overdensity of 500, and duplicate entries from overlaps between the survey areas of the individual input catalogues are carefully handled. The MCXC comprises 1743 clusters with virtually no duplicate entries. For each cluster the MCXC provides three identifiers, a redshift, coordinates, membership in the original catalogue, and standardised 0.1-2.4keV band luminosity L_500_, total mass M_500_, and radius R_500_. The meta-catalogue additionally furnishes information on overlaps between the input catalogues and the luminosity ratios when measurements from different surveys are available, and gives notes on individual objects.
278. Mean Positions and proper motions of 995 FK4Sup stars
ID:
ivo://CDS.VizieR/I/210
Title:
Mean Positions and proper motions of 995 FK4Sup stars
Short Name:
I/210
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalogue lists improved mean positions and proper motions for the 995 stars in the FK4 Supplement (Veroeff. Astron. Rechen-Inst. Heidelberg No 11, 1963) which were not included in the Fifth Fundamental Catalogue (Part I: "The Basic FK5", Fricke et al., 1988, Veroeff. Astron. Rechen-Inst. Heidelberg No 32, Catalogue I/149/; Part II: "The FK5 Extension", Fricke et al., 1991, Veroeff. Astron. Rechen-Inst. Heidelberg No 33, Catalogue I/175/). The main purpose of the FK4 Supplement was to stimulate further observations within absolute and differential programs of the stars listed in that catalogue with the aim of their inclusion as new fundamental stars into a future fundamental catalogue. The new fundamental stars should increase the star density without extending the magnitude limit to fainter magnitudes. Since the publication of the "Supplement-Katalog des FK3" (published in Astron-Geodaet. Jahrbuch 1954 and Astron-Geodaet. Jahrbuch 1956) these stars were included in many observing programs. Within work on deriving the FK5 Extension all stars in the FK4 Supplement had been treated in exactly the same way and improved mean positions and proper motions had thus been obtained for all FK4 Sup stars. For more details reference is made to the introduction of the FK5 Extension. FK4 Sup stars with the best astrometric data were included in the FK5 Extension for achieving a homogeneous distribution in magnitude and taking simultaneously into account an even distribution on the sky. This selection process included 992 of the 1987 FK4 Sup stars into the FK5 Extension. Although the astrometric precision of the stars given in the present catalogue is inferior to that of the FK4 Supplement stars included in the FK5 Extension, they deserve being published because a considerable number of observations has been obtained for these stars since about 1955, stimulated by the publication of the FK3 Supplement. The average mean epoch of observation of the stars given is therefore shifted to comparatively modern epochs (see the table in Section 2 of the publication). The astrometric precision of the stars presented here is better than for most other published star positions and proper motions, and the positions and proper motions are the best which could be derived from the available observations. These observations are published in the same catalogues as listed in the FK5, Part II on pages 139 ff. The apparent visual magnitudes are between 3.6 and 7.7 with a concentration around the mean value of 5.94. They are thus within the magnitude limit of the Basic FK5.
279. MEGA-H proper motion catalog
ID:
ivo://CDS.VizieR/V/126
Title:
MEGA-H proper motion catalog
Short Name:
V/126
Date:
21 Oct 2021
Publisher:
CDS
Description:
The catalogue MEGA-H is a result of a merging of star lists from the catalogue of stellar proper motions with respect to galaxies in 47 selected areas near the Main Meridional Section of the Galaxy (MEGA-G) (Kharchenko 1987) and from All-sky Compiled Catalogue of 2.5 Million Stars (ASCC-2.5) (Cat. <I/280>). Proper motions from the catalogue MEGA-G were reduced to the Hipparcos system by means of common with the ASCC-2.5 stars. The compiled proper motions in the Hipparcos system and their standard errors were computed as the weighted means. Equatorial coordinates are reduced to the equinox J2000 and epoch 1991.25. The catalogue MEGA-H contains 18169 stars. Stars are sorted in right ascension J2000 order.
280. Method for orientation angles of galaxies
ID:
ivo://CDS.VizieR/J/MNRAS/403/1625
Title:
Method for orientation angles of galaxies
Short Name:
J/MNRAS/403/1625
Date:
21 Oct 2021
Publisher:
CDS
Description:
A method is proposed for the determination of the position and inclination angles of the plane of a spiral galaxy based on the assumption that every spiral arm is a monotonic function of the radius against azimuthal angle. This method may yield more accurate results than the more commonly employed isophote method, which is subject to a number of drawbacks. Analytical study, calibration against other methods and examples of application of the proposed method to real galaxies are presented.

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