- ID:
- ivo://CDS.VizieR/J/other/ApSS/363.127
- Title:
- Bulge RR Lyrae VVVDR4 photometry
- Short Name:
- J/other/ApSS/363
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This study's objective was to exploit infrared VVV (VISTA Variables in the Via Lactea) photometry for high latitude RRab stars to establish an accurate Galactic Centre distance. RRab candidates were discovered and reaffirmed (n=4194) by matching Ks photometry with templates via chisq minimization, and contaminants were reduced by ensuring targets adhered to a strict period-amplitude (Ks) trend and passed the Elorietta et al. (2016A&A...595A..82E) classifier. The distance to the Galactic Centre was determined from a high latitude Bulge subsample (|b|>4, RGC=8.30+/-0.36kpc, random uncertainty is relatively negligible), and importantly, the comparatively low color-excess and uncrowded location mitigated uncertainties tied to the extinction law, the magnitude-limited nature of the analysis, and photometric contamination. Circumventing those problems resulted in a key uncertainty being the MKs relation, which was derived using LMC RRab stars (MKs=-(2.66+/-0.06)logP-(1.03+/-0.06), (J-Ks)0=(0.31+/-0.04)logP +(0.35+/-0.02), assuming mu0LMC=18.43). The Galactic Centre distance was not corrected for the cone-effect. Lastly, a new distance indicator emerged as brighter overdensities in the period-magnitude-amplitude diagrams analyzed, which arise from blended RRab and red clump stars. Blending may thrust faint extragalactic variables into the range of detectability.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/340/1346
- Title:
- Bulge SC1 proper motions
- Short Name:
- J/MNRAS/340/1346
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report a measurement of the streaming motion of the stars in the Galactic bar with the red clump giants (RCGs) using the data of the Optical Gravitational Lensing Experiment II (OGLE-II). We measure the proper motion of 46961 stars and divide RCGs into bright and faint subsamples that on average will be closer to the near and far sides of the bar, respectively. We find that the far-side RCGs (4979 stars) have a proper motion of {Delta}<{mu}>~1.5+/-0.11mas/yr toward the negative longitudes relative to the near-side RCGs (3610 stars).
- ID:
- ivo://CDS.VizieR/J/ApJ/716/942
- Title:
- Bulges of nearby galaxies with Spitzer
- Short Name:
- J/ApJ/716/942
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate scaling relations of bulges using bulge-disk decompositions at 3.6um and present bulge classifications for 173 E-Sd galaxies within 20Mpc. Pseudobulges and classical bulges are identified using Sersic index, Hubble Space Telescope morphology, and star formation activity (traced by 8um emission). In the near-IR pseudobulges have n_b_<2 and classical bulges have n_b_>2, as found in the optical. Sersic index and morphology are essentially equivalent properties for bulge classification purposes. We confirm, using a much more robust sample, that the Sersic index of pseudobulges is uncorrelated with other bulge structural properties, unlike for classical bulges and elliptical galaxies. Also, the half-light radius of pseudobulges is not correlated with any other bulge property. We also find a new correlation between surface brightness and pseudobulge luminosity; pseudobulges become more luminous as they become more dense.
- ID:
- ivo://CDS.VizieR/J/AJ/142/2
- Title:
- Burrell-Optical-Kepler-Survey (BOKS). I.
- Short Name:
- J/AJ/142/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the initial results of a 40 night contiguous ground-based campaign of time series photometric observations of a 1.39deg^2^ field located within the NASA Kepler Mission field of view. The goal of this pre-launch survey was to search for transiting extrasolar planets and to provide independent variability information of stellar sources. We have gathered a data set containing light curves of 54,687 stars from which we have created a statistical sub-sample of 13,786 stars between 14<r<18.5 and have statistically examined each light curve to test for variability. We present a summary of our preliminary photometric findings including the overall level and content of stellar variability in this portion of the Kepler field and give some examples of unusual variable stars found within. We present a preliminary catalog of 2,457 candidate variable stars, of which 776 show signs of periodicity. We also present three potential exoplanet candidates, all of which should be observable by the Kepler mission.
- ID:
- ivo://CDS.VizieR/J/A+A/357/471
- Title:
- BV and proper motions in NGC 1960 & NGC 2194
- Short Name:
- J/A+A/357/471
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CCD photometry and proper motion studies of the two open star clusters NGC 1960 (M 36) and NGC 2194. Fitting isochrones to the colour magnitude diagrams, for NGC 1960 we found an age of 16Myr and a distance of roughly 1300 pc and for NGC 2194 550Myr and 2900pc, respectively. We combined membership determination by proper motions and statistical field star subtraction to derive the initial mass function of the clusters and found slopes of -1.23+/-0.17 for NGC 1960 and -1.33+/-0.29 for NGC 2194. Compared to other IMF studies of the intermediate mass range, these values indicate shallow mass functions. These tables present the complete data of the photometry (Tables 2 and 3) and the proper motion studies (Tables 7 and 9) of the two clusters.
- ID:
- ivo://CDS.VizieR/J/A+AS/121/499
- Title:
- BV and rg photometry of Pal 13
- Short Name:
- J/A+AS/121/499
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new CCD photometry of the halo cluster Palomar 13 is used to construct a color-magnitude diagram in the Thuan-Gunn and the B, V photometric systems. The color-magnitude diagram of the cluster shows as already noted by Ortolani et al. (1985AJ.....90..473O) an extremely poor red horizontal branch and a very sparsely populated giant branch. Seven BSS candidates are identified in the field of Palomar 13. The age of the cluster determined by fitting with the isochrones of Proffitt & Vanden Berg (1991ApJS...77..473P) and Bergbusch & Vanden Berg (1992ApJS...81..163B) and by a differential comparison of the color-magnitude diagram with that of Pal 5 is 12+/-2Gyr.
- ID:
- ivo://CDS.VizieR/J/ApJ/780/L25
- Title:
- 1898-2013 BV and visual photometry for V603 Aql
- Short Name:
- J/ApJ/780/L25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the light curve of the old nova V603 Aql (Nova Aql 1918) from 1898-1918 and 1934-2013 using 22721 archival magnitudes. All of our magnitudes are either in, or accurately transformed into, the Johnson B and V magnitude systems. This is vital because offsets in old sequences and the visual-to-V transformation can cause errors of 0.1-1.0mag if not corrected. Our V603 Aql light curve is the first time that this has been done for any nova. Our goal was to see the evolution of the mass accretion rate on a century timescale, and to test the long-standing prediction of the Hibernation model that old novae should be fading significantly in the century after their eruption is over. The 1918 nova eruption was completely finished by 1938 when the nova decline stopped, and when the star had faded to fainter than its pre-nova brightness of B=11.43+/-0.03mag. We find that the nova light from 1938 to 2013 was significantly fading, with this being seen consistently in three independent data sets (the Sonneberg plates in B, the American Association of Variable Star Observers (AAVSO) V light curve, and the non-AAVSO V light curve). We find that V603 Aql has been declining in brightness at an average rate of 0.44+/-0.04mag per century since 1938. This work provides remarkable confirmation of an important prediction of the Hibernation model.
- ID:
- ivo://CDS.VizieR/J/A+A/463/981
- Title:
- BV CCD photometry in Westerlund 2
- Short Name:
- J/A+A/463/981
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The properties of the early-type stars in the core of the Westerlund 2 cluster are examined in order to establish a link between the cluster and the very massive Wolf-Rayet binary WR20a as well as the H II complex RCW 49. Photometric monitoring as well as spectroscopic observations of Westerlund 2 are used to search for light variability and to establish the spectral types of the early-type stars in the cluster core. The first light curves of the eclipsing binary WR 20a in B and V filters are analysed and a distance of 8kpc is inferred. Three additional eclipsing binaries, which are probable late O or early B-type cluster members, are discovered, but none of the known early O-type stars in the cluster displays significant photometric variability above 1% at the 1-sigma level. The twelve brightest O-type stars are found to have spectral types between O3 and O6.5, significantly earlier than previously thought. The distance of the early-type stars in Westerlund 2 is established to be in excellent agreement with the distance of WR20a, indicating that WR20a actually belongs to the cluster. Our best estimate of the cluster distance thus amounts to 8.0+/-1.4kpc. Despite the earlier spectral types, the currently known population of early-type stars in Westerlund 2 does not provide enough ionizing photons to account for the radio emission of the RCW 49 complex. This suggests that there might still exist a number of embedded early O-stars in RCW49.
- ID:
- ivo://CDS.VizieR/J/PASP/104/1063
- Title:
- BV Color-Magnitude Diagram for NGC 1851
- Short Name:
- J/PASP/104/1063
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- BV photometry is provided for 1,234 stars in the magnitude range 13-18 in an annulus between 5 and 20 arc seconds from the center of NGC 1851 and for 1,247 stars in the magnitude range 18-23 at a distance of more than 240 arc seconds from the center. For stars in the magnitude range 16-21, the errors in B-V increase with magnitude from 0.005 mag. to 0.022 mag. See the document file (walker.txt or walker.tex) by Nancy G. Roman for more details.
- ID:
- ivo://CDS.VizieR/J/A+A/344/263
- Title:
- B-V colour excess of Miras
- Short Name:
- J/A+A/344/263
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A study of 73 carbon-rich Miras (see Subsec. 6.1) with suitable solution for 56 stars at one or several phase of their variations. In the second part, preliminary and incomplete results are reported for 17 additional Miras observed at only one phase. Table 5 contains our HC-CV-classification (see text) for the stars and their colour excess E(B-V) as determined by the method described in Subsec. 2.2.
