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241. Galilean satellites mutual events in 2009
ID:
ivo://CDS.VizieR/J/A+A/532/A36
Title:
Galilean satellites mutual events in 2009
Short Name:
J/A+A/532/A36
Date:
21 Oct 2021
Publisher:
CDS
Description:
Photometry of mutual events between natural satellites has been verified to be a most effective and accurate ground-based method for obtaining accurate astrometric data through fitting the light curves observed during these events, and it will be valuable to develop the orbital models of the natural satellites. Mutual occultations of J2 Europa by J1 Io (Aug 28, 2009), J1 Io by J2 Europa (Nov 9 and Dec 11, 2009) and J1 Io by J3 Ganymede (Nov 28, 2009) were observed at Yunnan Observatory during the PHEMU09 international campaign. We will calculate the astrometric data of satellites by analyzing and fitting the light curves we got. The same model proposed by N.V. Emelianov (2003SoSyR..37..314E) was used to fit the light curves, with the Lommel-Seeliger scattering law taking into account. Dynamical quantities, such as the deviation of the observed relative satellite motion from the theoretical motion provided by the relevant ephemeris denoted as Dx and Dy, impact parameter and mid-time corresponding to the impact parameter, were obtained for each event respectively. These results have an accuracy of about several mas to 90mas for Dx and Dy and 0.31-2.97s for mid-time. The residuals in determination of longitude shifts (delta(l1) for J1 Io and delta(l2) for J2 Europa) explaining the shifts of the mid-times of the events, were also calculated in the section of discussion which is around 10km with the best ephemerides.
242. General Catalogue of Stars
ID:
ivo://CDS.VizieR/I/180
Title:
General Catalogue of Stars
Short Name:
I/180
Date:
21 Oct 2021
Publisher:
CDS
Description:
The general Catalogue reported here has been Compiled on the basis of the preliminary catalogues consisting of the long series observations of the fundamental programs (mainly of FK4 stars) of the Mark I photoelectric astrolabe of Shaanxi Astronomical Observatory and Mark II photoelectric astrolobes of Beijing, Shanghai and Yunnan Astronomical Observatories, together with a large amount of observations of catalogue stars carried out in Beijing, Shanghai and Shaanxi, as well as 4 preliminary catalogues of Danjon's astrolabes derived from the observations of OPL No.14 of Shanghai, No.30 of Beijing and No.29 of Wuchang. With magnitudes ranging from 0.1 to 7.2, the GCPA consists of 1579 stars. The declinations are from -3.6 degree to 68.8 degree, in which 642 are FK4 stars. The mean precisions of position corrections are 3.3 ms and 0.058" in right ascension and declination, respectively. The mean epoch of GCPA is 1987.8.
243. General Catalogue of 33342 stars (GC)
ID:
ivo://CDS.VizieR/I/113A
Title:
General Catalogue of 33342 stars (GC)
Short Name:
I/113A
Date:
21 Oct 2021
Publisher:
CDS
Description:
The GC is a catalog of standard positions and proper motions for (all) stars brighter than magnitude 7, extending from the north to south celestial poles. Several thousand additional stars promising to yield reasonably accurate proper motions were included in the catalog. The objectives of the work were to provide standard positions and motions of accuracy limited only by the character and abundance of the observational material upon which the data were based and thus to provide a rich supply of data to promote research in many astronomical fields. The machine version of the GC includes both The Henry Draper Catalogue and Durchmusterung identifications for all stars, although the published GC contains only one or the other. The 1985 version corrected many errors present in a previous machine version and included probable errors for the positions and centennial proper motions (not present in the previous version). In this version decimal points have been aligned for all but a very few of the secular variations and third terms. These quantities are given with the same precision as in the printed catalog, and the coded spectral types have been omitted. The following quantities are included in the machine but not the published version: galactic coordinates and DM numbers. The following data are in the published but not the machine version: centennial increments of proper motion in right ascension and declination, probable errors of the right ascension and declination at 1950.0, and remarks. The documentation supplied with the machine catalog gives a byte-by-byte format description, indigenous catalog characteristics, code explanation tables, and changes incorporated to produce this and previous Astronomical Data Center versions.
244. Geneva-Copenhagen Survey of Solar neighbourhood
ID:
ivo://CDS.VizieR/V/117A
Title:
Geneva-Copenhagen Survey of Solar neighbourhood
Short Name:
V/117A
Date:
21 Oct 2021
Publisher:
CDS
Description:
(from paper II, 2007) Ages, metallicities, space velocities, and Galactic orbits of stars in the Solar neighbourhood are fundamental observational constraints on models of galactic disk evolution. Understanding and minimising systematic errors and sample selection biases in the data is crucial for their interpretation. We aim to consolidate the calibrations of uvbyb photometry into T_eff_, [Fe/H], distance, and age for F and G stars and rediscuss the results of the Geneva-Copenhagen Survey (GCS, Nordstrom et al., 2004, paper I) in terms of the evolution of the disk. We use recent V-K photometry, angular diameters, high-resolution spectroscopy, Hipparcos parallaxes, and extensive numerical simulations to re-examine and verify the temperature, metallicity, distance, and reddening calibrations for the uvbyb system. We also highlight the selection effects inherent in the apparent-magnitude limited GCS sample. We substantially improve the T_eff_ and [Fe/H] calibrations for early F stars, where spectroscopic temperatures have large systematic errors. A slight offset of the GCS photometry and the non-standard helium abundance of the Hyades invalidate its use for checking metallicity or age scales; however, the distances, reddenings, metallicities, and age scale for GCS field stars require minor corrections only. Our recomputed ages are in excellent agreement with the independent determinations by Takeda et al. (2007ApJS..168..297T), indicating that isochrone ages can now be reliably determined. The revised G-dwarf metallicity distribution remains incompatible with closed-box models, and the age-metallicity relation for the thin disk remains almost flat, with large and real scatter at all ages sigma_intrinsic=0.20 dex). Dynamical heating of the thin disk continues throughout its life; specific in-plane dynamical effects dominate the evolution of the U and V velocities, while the W velocities remain random at all ages. When assigning thick and thin-disk membership for stars from kinematic criteria, parameters for the oldest stars should be used to characterise the thin disk.
245. Geneva-Copenhagen Survey of Solar neighbourhood III
ID:
ivo://CDS.VizieR/V/130
Title:
Geneva-Copenhagen Survey of Solar neighbourhood III
Short Name:
V/130
Date:
21 Oct 2021
Publisher:
CDS
Description:
Ages, chemical compositions, velocity vectors, and Galactic orbits for stars in the solar neighbourhood are fundamental test data for models of Galactic evolution. The Geneva-Copenhagen Survey of the Solar neighbourhood (Nordstrom et al. 2004A&A...418..989N; GCS), a magnitude-complete, kinematically unbiased sample of 16,682 nearby F and G dwarfs, is the largest available sample with complete data for stars with ages spanning that of the disk. We aim to improve the accuracy of the GCS data by implementing the recent revision of the Hipparcos parallaxes. The new parallaxes yield improved astrometric distances for 12,506 stars in the GCS. We also use the parallaxes to verify the distance calibration for uvbyHbeta photometry by Holmberg et al. (2007A&A...475..519H; GCS II, Cat. VI/117). We add new selection criteria to exclude evolved cool stars giving unreliable results and derive distances for 3,580 stars with large parallax errors or not observed by Hipparcos. We also check the GCS II scales of T_eff_ and [Fe/H] and find no need for change. From the new distances we compute revised Mv, U, V, W, and Galactic orbital parameters for 13,520 GCS stars. We also recompute stellar ages with the new values of Mv from the Padova stellar evolution models used in GCS I-II, and compare them with ages from the Yale-Yonsei and Victoria-Regina models. Finally, we compare the observed age-velocity relation in W with three simulated disk heating scenarios to show the potential of the data. With these revisions, the basic data for the GCS stars should now be as reliable as is possible with existing techniques. Further improvement must await consolidation of the T_eff_ scale from angular diameters and fluxes, and the Gaia trigonometric parallaxes. We discuss the conditions for improving computed stellar ages from new input data, and for distinguishing different disk heating scenarios from data sets of the size and precision of the GCS.
246. Geneva-Copenhagen survey re-analysis
ID:
ivo://CDS.VizieR/J/A+A/530/A138
Title:
Geneva-Copenhagen survey re-analysis
Short Name:
J/A+A/530/A138
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a re-analysis of the Geneva-Copenhagen survey, benefiting from the infrared flux method to improve upon the accuracy of the derived stellar effective temperatures and using the latter to build a consistent and improved metallicity scale. Metallicities are calibrated on high-resolution spectroscopy and checked against four open clusters and a moving group, showing excellent consistency. The new temperature and metallicity scales provide a better match to theoretical isochrones, which are used for a Bayesian analysis of stellar ages. With respect to previous analyses, our stars are on average 100K hotter and 0.1dex more metal rich, shifting the peak of the metallicity distribution function around the solar value. From Stromgren photometry we are able to derive for the first time a proxy for [Fe] abundances, which enables for a tentative dissection of the chemical thin and thick disc. We find evidence for the latter being composed of an old, mildly but systematically alpha-enhanced population extending to super solar metallicities, in agreement with spectroscopic studies. Our revision offers the largest existing kinematically unbiased sample of the solar neighbourhood that contains full information on kinematics, metallicities and ages and thus provides better constraints on the physical processes relevant in the build-up of the Milky Way disc, enabling a better understanding of the Sun in a Galactic context.
247. 1.4GHz First Look Survey (FLS)
ID:
ivo://CDS.VizieR/J/A+A/424/371
Title:
1.4GHz First Look Survey (FLS)
Short Name:
J/A+A/424/371
Date:
21 Oct 2021
Publisher:
CDS
Description:
The First Look Survey (FLS) is the first scientific product to emerge from the Spitzer Space Telescope. A small region of this field (the verification strip) has been imaged very deeply, permitting the detection of cosmologically distant sources. We present Westerbork Synthesis Radio Telescope (WSRT) observations of this region, encompassing a 1 sq. deg field, centred on the verification strip (J2000 RA=17:17:00.00, DE=59:45:00.000). The radio images reach a noise level of 8.5 microJy per beam - the deepest WSRT image made to date. We summarise here the first results from the project, and present the final mosaic image, together with a list of detected sources. The effect of source confusion on the position, size and flux density of the faintest sources in the source catalogue are also addressed. The results of a serendipitous search for HI emission in the field are also presented. Using a subset of the data, we clearly detect HI emission associated with four galaxies in the central region of the FLSv. These are identified with nearby, massive galaxies.
248. GLEAM sources ionospheric position shifts
ID:
ivo://CDS.VizieR/VIII/107
Title:
GLEAM sources ionospheric position shifts
Short Name:
VIII/107
Date:
22 Feb 2022
Publisher:
CDS
Description:
Nearly 200 hours of observing with the Murchison Widefield Array (MWA) radio telescope during the Galactic and Extra-galactic All-sky MWA (GLEAM) survey were used to assemble images of ionospheric structure. These images cover a nearly 50 degree-wide area on the sky at a cadence of 10 minutes over many 5-7 hours-long observing runs. They are generated by tracking the apparent motions of ~200-800 cosmic radio sources caused by changes in the transverse gradient of the ionospheric total electron content. Spectral analysis of these images revealed that the dataset was dominated by three distinct signatures. The first is consistent with field-aligned structures within the topside ionosphere/lower plasmasphere previously imaged with the MWA. The second are structures that are relatively large and aligned nearly east/west. Regional weather data implies that these are preferentially detected when there is a noticeable shear within the sub- tropical jet stream, which passes near the MWA. This suggests that this signature may be related to gravity waves launched by jet stream shear. The final signature is consistent with the properties of so-call electro-buoyancy waves that are known to occur at midlatitudes at night. Detections of these were more common when regional sporadic-E was present, supporting a proposed connection between these waves and polarization electric fields that may arise within sporadic-E. We discuss the implications for future observations with the Square Kilometer Array.
249. 4 globular clusters RGB and AGB stars
ID:
ivo://CDS.VizieR/J/A+A/603/A37
Title:
4 globular clusters RGB and AGB stars
Short Name:
J/A+A/603/A37
Date:
21 Oct 2021
Publisher:
CDS
Description:
Spectroscopic studies have demonstrated that nearly all Galactic globular clusters (GCs) harbour multiple stellar populations with different chemical compositions. Moreover, colour-magnitude diagrams based exclusively on Stroemgrem photometry have allowed us to identify and characterise multiple populations along the RGB of a large number of clusters. In this paper we show for the first time that Stroemgren photometry is also very efficient at identifying multiple populations along the AGB, and demonstrate that the AGB of M3, M92, NGC362, NGC1851, and NGC6752 are not consistent with a single stellar population. We also provide a catalogue of RGB and AGB stars photometrically identified in these clusters for further spectroscopic follow-up studies. We combined photometry and elemental abundances from the literature for RGB and AGB stars in NGC6752 where the presence of multiple populations along the AGB has been widely debated. We find that, while the MS, SGB, and RGB host three stellar populations with different helium and light element abundances, only two populations of AGB stars are present in the cluster. These results are consistent with standard evolutionary theory.
250. Harvard variables
ID:
ivo://CDS.VizieR/J/other/IBVS/5298
Title:
Harvard variables
Short Name:
J/other/IBVS/529
Date:
21 Oct 2021
Publisher:
CDS
Description:
Coordinates and identifications are presented for 726 Harvard Variable stars and suspected variables, discovered or studied by D. Hoffleit and announced in Harvard Bulletins 874, 884, 887, 901, and 902; plus 141 others, previously known, lying in the same fields.

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