- ID:
- ivo://CDS.VizieR/J/A+A/450/855
- Title:
- Methods for CIP and CIO localisation
- Short Name:
- J/A+A/450/855
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The precession-nutation transformation describes the changing directions on the celestial sphere of the Earth's pole and an adopted origin of right ascension. The coordinate system for the celestial sphere is the geocentric celestial reference system, and the two directions are the celestial intermediate pole (CIP) and the celestial intermediate origin (CIO), the latter having supplanted the equinox for this purpose following IAU resolutions in 2000. The celestial coordinate triad based on the CIP and CIO is called the celestial intermediate reference system; the prediction of topocentric directions additionally requires the Earth rotation angle (ERA), the counterpart of Greenwich sidereal time (GST) in the former equinox based system. The purpose of this paper is to review the different ways of calculating the CIP and CIO directions to precisions of a few microarcseconds over a time span of several centuries, meeting the requirements of high-accuracy applications.
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- ID:
- ivo://CDS.VizieR/VIII/98
- Title:
- 180MHz Murchison Commissioning Survey (MWACS)
- Short Name:
- VIII/98
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Murchison Widefield Array Commissioning Survey (MWACS) is a ~6100deg^2^ 104-196MHz radio sky survey performed with the Murchison Widefield Array during instrument commissioning between 2012 September and 2012 December. The data were taken as meridian drift scans with two different 32-antenna sub-arrays that were available during the commissioning period. The data were combined in the visibility plane before being imaged, and then mosaicked. The survey covers approximately 20.5h<RA<8.5h, -58{deg}<Dec<-14{deg} over three frequency bands centred on 119, 150 and 180MHz. The survey has 3arcmin angular resolution and a typical noise level of 40mJy/beam, with reduced sensitivity near the field boundaries and bright sources. The catalogue consists of flux density and spectral index measurements for 14,110 sources, extracted from the mosaics, 1,247 of which are sub-components of complexes of sources.
- ID:
- ivo://CDS.VizieR/J/A+AS/143/335
- Title:
- Micrometer measurements of double stars
- Short Name:
- J/A+AS/143/335
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report 312 micrometer measurements of 155 visual double stars made with the 50 cm refractor at the Cote D'Azur observatory (Nice, France) and with the 152 cm telescope at Calar Alto observatory (Almeria, Spain).
- ID:
- ivo://CDS.VizieR/J/A+A/551/A129
- Title:
- Mimas and Enceladus Cassini ISS astrometry
- Short Name:
- J/A+A/551/A129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We provide the Cassini ISS astrometric observations of the Saturnian satellites Mimas and Enceladus. The observations were taken over 6 years. Observation residuals were compared to JPL ephemerides SAT317 and SAT351, showing that the observation error is between 3 and 4 kilometers.
- ID:
- ivo://CDS.VizieR/J/A+A/278/36
- Title:
- M 31 new OB associations
- Short Name:
- J/A+A/278/36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new identification of OB associations in M 31 has been performed using the Path Linkage Criterion technique of Battinelli (1991A&A...244...69B). We found 174 associations with a very small contamination (<5%) by random clumps stars. The expected total number and average size of OB associations in the region of M 31 covered by our data set (Magnier et al., 1992, Cat. <II/208>) are ~280 and ~90pc, respectively. M 31 associations therefore have sizes similar to those of OB associations observed in nearby galaxies, so that we can consider them to be classical OB associations. This list of OB associations will be used for the study of the spatial distribution of OB associations and their correlation with other objects. Taking into account the fact that we do not cover the entire disk of M 31, we extrapolate a total number of associations in M 31 of ~420.
- ID:
- ivo://CDS.VizieR/J/A+A/626/A20
- Title:
- MONOS. I. Spectral classifications
- Short Name:
- J/A+A/626/A20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Multiplicity in massive stars is a key element to understand the chemical and dynamical evolution of galaxies. Among massive stars, those of O type play a crucial role due to their high masses and short lifetimes. MONOS (Multiplicity Of Northern O-type Spectroscopic systems) is a project designed to collect information and study O-type spectroscopic binaries with {delta}>20{deg}. In this first paper we describe the sample and provide spectral classifications and additional information for objects with previous spectroscopic and/or eclipsing binary orbits. In future papers we will test the validity of previous solutions and calculate new spectroscopic orbits. The spectra in this paper have two sources: the Galactic O-Star Spectroscopic Survey (GOSSS), a project that is obtaining blue-violet R~2500 spectroscopy of thousands of massive stars, and LiLiMaRlin, a library of libraries of high-resolution spectroscopy of massive stars obtained from four different surveys (CAFE-BEANS, OWN, IACOB, and NoMaDS) and additional data from our own observing programs and public archives. We also use lucky images obtained with AstraLux. We present homogeneous spectral classifications for 92 O-type spectroscopic multiple systems and ten optical companions, many of them original.We discuss the visual multiplicity of each system with the support of AstraLux images and additional sources. For eleven O-type objects and for six B-type objects we present their first GOSSS spectral classifications. For two known eclipsing binaries we detect double absorption lines (SB2) or a single moving line (SB1) for the first time, to which we add a third system already reported by us recently. For two previous SB1 systems we detect their SB2 nature for the first time and give their first separate spectral classifications, something we also do for a third object just recently identified as a SB2. We also detect nine new astrometric companions and provide updated information on several others. We emphasize the results for two stars: for {sigma} Ori AaAbB we provide spectral classifications for the three components with a single observation for the first time thanks to a lucky spectroscopy observation obtained close to the Aa,Ab periastron and for {theta}^1^ Ori CaCb we add it to the class of Galactic Of?p stars, raising the number of its members to six. Our sample of O-type spectroscopic binaries contains more triple- or higher-order systems than double systems.
- ID:
- ivo://CDS.VizieR/J/AJ/151/41
- Title:
- Motion Verified Red Stars (MoVeRS)
- Short Name:
- J/AJ/151/41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a photometric catalog of 8,735,004 proper motion selected low-mass stars (KML-spectral types) within the Sloan Digital Sky Survey (SDSS) footprint, from the combined SDSS-DR10, Two-Micron All-Sky Survey (2MASS) Point Source Catalog (PSC), and Wide-field Infrared Survey Explorer (WISE) AllWISE catalog. Stars were selected using r-i, i-z, r-z, z-J, and z-W1 colors, and SDSS, WISE, and 2MASS astrometry was combined to compute proper motions. The resulting 3,518,150 stars were augmented with proper motions for 5,216,854 earlier type stars from the combined SDSS and United States Naval Observatory B1.0 catalog (USNO-B). We used SDSS+USNO-B proper motions to determine the best criteria for selecting a clean sample of stars. Only stars whose proper motions were greater than their 2-sigma uncertainty were included. Our Motion Verified Red Stars (MoVeRS) catalog is available through SDSS CasJobs and VizieR.
- ID:
- ivo://CDS.VizieR/J/PAZh/24/93
- Title:
- M 31 reference catalog
- Short Name:
- J/PAZh/24/93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We compiled a catalog of 421 references 12-15mag stars for determining accurate positions of objects in the region of M 31. We also compiled a star chart, which is provided as an Internet Web service, for identifying the catalogued reference stars on the plates of observers. AQccurate positions and a finding chart are given for 33 reference 15-17mag stars in a 10'x12' field near the center of M 31.
- ID:
- ivo://CDS.VizieR/J/A+A/567/A111
- Title:
- Multi-color detection of gravitational arcs
- Short Name:
- J/A+A/567/A111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Strong gravitational lensing provides fundamental insights into the understanding of the dark matter distribution in massive galaxies, galaxy clusters and the background cosmology. Despite their importance, the number of gravitational arcs discovered so far is small. The urge for more complete, large samples and unbiased methods of selecting candidates is rising. A number of methods for the automatic detection of arcs have been proposed in the literature, but large amounts of spurious detections retrieved by these methods forces observers to visually inspect thousands of candidates per square degree in order to clean the samples. This approach is largely subjective and requires a huge amount of eye-ball checking, especially considering the actual and upcoming wide field surveys, which will cover thousands of square degrees. In this paper we study the statistical properties of colours of gravitational arcs detected in the 37deg^2^ of the CARS survey.
- ID:
- ivo://CDS.VizieR/J/A+A/630/A101
- Title:
- Multi-frequency celestial reference frame
- Short Name:
- J/A+A/630/A101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a celestial reference frame (CRF) based on the combination of independent, multifrequency radio source position catalogs using nearly 40 years of very long baseline interferometry observations at the standard geodetic frequencies at SX band and about 15 years of observations at higher frequencies (K and XKa). The final catalog contains 4617 sources. We produce a multifrequency catalog of radio source positions with full variance-covariance information across all radio source positions of all input catalogs. We combined three catalogs, one observed at 8GHz (X band), one at 24GHz (K band) and one at 32GHz (Ka band). Rather than only using the radio source positions, we developed a new, rigorous combination approach by carrying over the full covariance information through the process of adding normal equation systems. Special validation routines were used to characterize the random and systematic errors between the input reference frames and the combined catalog. The resulting CRF contains precise positions of 4617 compact radio astronomical objects, 4536 measured at 8GHz, 824 sources also observed at 24GHz, and 674 at 32GHz. The frame is aligned with ICRF3 within +/-3{mu}as and shows an average positional uncertainty of 0.1mas in right ascension and declination. No significant deformations can be identified. Comparisons with Gaia-CRF remain inconclusive, nonetheless significant differences between all frames can be attested.
