- ID:
- ivo://CDS.VizieR/J/other/Ap/48.304
- Title:
- BVRI of comparison stars in AGN fields
- Short Name:
- J/other/Ap/48.30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results are presented from CCD BVRI-observations of 145 comparison stars in the neighborhoods of 14 Seyfert galaxies, 3 quasars, and 5 BL Lac objects with right ascensions of 12 to 24 hours. The magnitudes of the observed stars ranged from V=11 to V=17. The typical photometric error for stars brighter V=14 is 0.01m. The B, V, Rc, and Ic magnitudes of most of these stars were not known previously. 14'x14' finding charts are provided. These results can be used for differential photometry of the nuclei of active galaxies in the B, V, Rc, and Ic bands.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+AS/126/73
- Title:
- BVRI photometry in dark globules
- Short Name:
- J/A+AS/126/73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using a CCD detector, BVRI photometry has been carried out in the vicinity of nine Lynds dark nebulae. In conjunction with spectroscopic data which could be obtained at a later stage, the data listed herein could be used for possible distance determinations of the nine nebulae.
- ID:
- ivo://CDS.VizieR/J/AJ/122/1125
- Title:
- BVRI photometry in 3 high-z clusters
- Short Name:
- J/AJ/122/1125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New photometric and spectroscopic observations of galaxies in the directions of three distant clusters are presented as part of our ongoing high-redshift cluster survey. The clusters are Cl 1324+3011 at z=0.76, Cl 1604+4304 at z=0.90, and Cl 1604+4321 at z=0.92. We have spectroscopically confirmed cluster membership for 2040 galaxies in each system and have also obtained spectra for over 280 field galaxies spanning the range 0<z<2.5.
- ID:
- ivo://CDS.VizieR/J/A+A/419/167
- Title:
- BVRI photometry in metal-poor binaries
- Short Name:
- J/A+A/419/167
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We explored the regions within a radius of 25 arcsec around 473 nearby, low-metallicity G- to M-type stars using (VR)I optical filters and small-aperture telescopes. About 10% of the sample was searched up to angular separations of 90 arcsec. We applied photometric and astrometric techniques to detect true physical companions to the targets. The great majority of the sample stars was drawn from the Carney-Latham surveys; their metallicities range from roughly solar to [Fe/H]=-3.5dex. Our I-band photometric survey detected objects that are between 0 and 5mag fainter (completeness) than the target stars; the maximum dynamical range of our exploration is 9mag.
- ID:
- ivo://CDS.VizieR/J/AJ/145/165
- Title:
- BVRI photometry in NGC 6496
- Short Name:
- J/AJ/145/165
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-quality BVRI photometric data in the field of globular cluster NGC6496 obtained with the SOAR Telescope Adaptive Module (SAM). Our observations were collected as part of the ongoing SAM commissioning. The distance modulus and cluster color excess as found from the red clump are (m-M)_V_=15.71+/-0.02mag and E(V-I)=0.28+/-0.02mag. An age of 10.5+/-0.5Gyr is determined from the difference in magnitude between the red clump and the subgiant branch. These parameters are in excellent agreement with the values derived from isochrone fitting. From the color-magnitude diagram we find a metallicity of [Fe/H]=-0.65dex and hence support a disk classification for NGC 6496. The complete BVRI data set for NGC6469 is made available in the electronic edition of the Journal.
- ID:
- ivo://CDS.VizieR/J/PASP/117/1325
- Title:
- BVRI photometry in NGC4147
- Short Name:
- J/PASP/117/1325
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New BVRI broadband photometry and astrometry are presented for the globular cluster NGC 4147, based upon measurements derived from 524 ground-based CCD images mostly either donated by colleagues or retrieved from public archives. We have also reanalyzed five exposures of the cluster obtained with WFPC2 on the Hubble Space Telescope in the F439W and F555W (B and V) filters.
- ID:
- ivo://CDS.VizieR/J/PASP/117/37
- Title:
- BVRI photometry in NGC 2419, Pal 4, and Pal 14
- Short Name:
- J/PASP/117/37
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results from work done to extend the Johnson-Cousins BVRI photometric standard sequence to faint levels of V~21mag in compact fields is presented. Such calibration and extension of sequences is necessary to fill a calibration gap if reliable photometry from modest aperture telescopes in space (e.g., the Hubble Space Telescope) or terrestrial telescopes with apertures exceeding 4m is to be done. Sequences like the ones presented here, which cover a large range in brightness as well as color, will allow photometric calibration to be done efficiently and will also make such work less prone to systematic sources of error. Photometry of stars in approximately 10'x10' fields around three globular clusters (NGC 2419, Pal 4, and Pal 14) are presented from data acquired over several photometric nights. In each field, several stars are measured in B, V, R, and I passbands, with standard errors in the mean less than 0.015mag from random errors, to levels fainter than V=21mag.
- ID:
- ivo://CDS.VizieR/J/AJ/122/38
- Title:
- BVRI photometry of Abell 2443
- Short Name:
- J/AJ/122/38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present broadband photometry and provide a quantitative analysis of the structure of galaxies in the inner region of the Abell Cluster 2443 (z~0.1). The galaxy parameters have been derived by fitting a two-component model (Sersic r^1/n^ bulge and exponential disk) to a magnitude-limited sample. Using a new method of analysis that takes into account the effects of seeing on the structural parameters and considers ellipticity as an active parameter, we avoid systematic errors arising from assumptions of circular symmetry. Of the sample galaxies, 76% were classified with these models, while the rest were morphologically peculiar. For the spiral galaxies, the relation between n and B/D is consistent with the trend observed in nearby field galaxy samples. The Sersic index n (which can be considered as a concentration index) of the elliptical galaxies is correlated with the local surface density of the cluster. Monte Carlo simulations were used to check the reliability of the method and determine the magnitude selection criteria. Observations were obtained on 1998 August 19 at the 2.5 m Nordic Optical Telescope (NOT) at the Observatorio del Roque de los Muchachos on La Palma. The prime-focus CCD camera was used with pixel scale of 0.11"/pix, and the seeing ranged from FWHM 0.88" to 1".
- ID:
- ivo://CDS.VizieR/J/AJ/134/778
- Title:
- BVRI photometry of candidate subdwarfs
- Short Name:
- J/AJ/134/778
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Optical (BVRI) photometric measurements of a sample of 564 candidate cool subdwarfs in the nearby halo are presented. The stars generally span the color range 0.4<(B-V)<1.8; hence, the sample is composed of early F- through early M-type stars on the subdwarf sequence. The sample is selected from the revised NLTT catalog of Gould and Salim and Salim and Gould via a reduced proper motion diagram. The photometry is precise and accurate; in particular, for stars with 9<V<13.5 the photometry is accurate to 0.013, 0.015, 0.012, and 0.013mag in V, B-V, V-R, and V-I, respectively. For stars with 13.5<V<16 the photometry is accurate to 0.022, 0.018, 0.013, and 0.018mag in the same bands.
- ID:
- ivo://CDS.VizieR/J/A+A/574/A33
- Title:
- BVRI photometry of high-mass X-ray binaries
- Short Name:
- J/A+A/574/A33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometric observations of the field around the optical counterparts of high-mass X-ray binaries. Our aim is to study the long-term photometric variability in correlation with their X-ray activity and derive a set of secondary standard stars that can be used for time series analysis. We find that the donors in Be/X-ray binaries exhibit larger amplitude changes in the magnitudes and colours than those hosting a supergiant companion. The amplitude of variability increases with wavelength in Be/X-ray binaries and remains fairly constant in supergiant systems. When time scales of years are considered, a good correlation between the X-ray and optical variability is observed. The X-rays cease when optical brightness decreases. These results reflect the fact that the circumstellar disk in Be/X-ray binaries is the main source of both optical and X-ray variability. We also derive the colour excess, E(B-V), selecting data at times when the contribution of the circumstellar disk was supposed to be at minimum, and we revisit the distance estimates.
