- ID:
- ivo://CDS.VizieR/J/A+AS/133/197
- Title:
- uvby Photometry of 33 Tau, HD 50169 and HR 7786
- Short Name:
- J/A+AS/133/197
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Differential Stroemgren uvby photometric observations from the Four College Automated Photoelectric Telescope are presented for the ellipsoidal variable 33 Tauri, and the magnetic Chemically Peculiar stars HD 50169 and HR 7786. We confirm that Hube's period of 2.975272 days for 33 Tau is correct. HD 50169 is a constant MCP star. HR 7786 is a large amplitude class member confirming Winzer's discovery, but its period is 8.5297 days. Its comparison star, HR 7721, a spectroscopic binary B7 V star, is variable with an amplitude of order 0.1mag, but of indeterminant period. In addition Hipparcos photometry of the comparison and check stars for early type stars whose photometry is being obtained with the FCAPT is reviewed to ascertain the stability of these stars.
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22182. uvby photometry of theta CrB
- ID:
- ivo://CDS.VizieR/J/A+A/329/579
- Title:
- uvby photometry of theta CrB
- Short Name:
- J/A+A/329/579
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present differential uvby photometry of {theta} CrB obtained in 1994 and 1995, complemented by Balmer line spectroscopy. This star has been constant during this period, showing no short term periodic variability with an amplitude greater than 0.005mag., nor long term variations greater than 0.01mag. The lack of variability is associated with an inactive phase of the Be star, in which no emission features are present in the spectra. The only remarkable event observed was a fading episode on JD 2449779, with an amplitude of about 0.02 magnitudes in all bandpasses and duration of 0.2-0.3 days.
- ID:
- ivo://CDS.VizieR/J/other/JAD/23.1
- Title:
- uvby photometry of theta Tucanae
- Short Name:
- J/other/JAD/23.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- theta Tucanae (HR 139, V=6.11, A7 IV) is a binary with a delta Scuti primary that was the subject of several photometric monitoring campaigns during the 1970s and again in the 1990s. The data presented in this paper were collected during an observing campaign from mid-September to the end of October 1993 at ESO La Silla, Chile, using the simultaneous Stroemgren uvby photometer at the SAT telescope during 25 partial nights. We present a time series of 1432 four-colour extinction-corrected magnitudes in the SAT instrumental system. This collection of data forms a homogeneous and contiguous dataset, obtained in one single instrumental setup, at one single observing site using one single observing protocol, and with centralized data reduction.
22184. uvby photometry of V Crt
- ID:
- ivo://CDS.VizieR/J/A+AS/101/49
- Title:
- uvby photometry of V Crt
- Short Name:
- J/A+AS/101/49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
22185. uvby photometry of V3903 Sgr
- ID:
- ivo://CDS.VizieR/J/A+AS/128/251
- Title:
- uvby photometry of V3903 Sgr
- Short Name:
- J/A+AS/128/251
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Complete uvby light curves of the young detached double-lined massive O-type eclipsing binary V3903 Sagittarii, obtained from 1989 to 1994, are presented. The observations were obtained at two different sites and a discussion of the characteristics of both data sets is included.
- ID:
- ivo://CDS.VizieR/J/A+A/389/931
- Title:
- uvby photometry & radial velocities of R 81
- Short Name:
- J/A+A/389/931
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- File table1.dat contains the photometric uvby data of the eclipsing binary hypergiant R81 (B2.5 Ia-O) of the Large Magellanic Cloud. The data have been obtained with the Danish 50 cm telescope at ESO, La Silla, and cover more than one orbital cycle of 74.59 days. File table2.dat contains radial velocity measurements of photospheric lines of this star. The spectra have been obtained simultaneously with the photometry. The Feros spectrograph at the ESO 1.52m telescope was used. The quoted radial velocities are averages over the best photospheric lines.
- ID:
- ivo://CDS.VizieR/J/MNRAS/363/529
- Title:
- uvby, UBV and radial velocity of WW Aur
- Short Name:
- J/MNRAS/363/529
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- WW Aurigae is a detached eclipsing binary composed of two metallic- lined A-type stars orbiting each other every 2.5 days. We have determined the masses and radii of both components to accuracies of 0.4% and 0.6%, respectively. From a cross-correlation analysis of high-resolution spectra we find masses of 1.964+/-0.007M_{sun}_ for the primary star and 1.814+/-0.007M_{sun}_ for the secondary star. From an analysis of photoelectric uvby and UBV light curves we find the radii of the stars to be 1.927+/-0.011R_{sun}_ and 1.841+/-0.011R_{sun}_, where the uncertainties have been calculated using a Monte Carlo algorithm. Fundamental effective temperatures of the two stars have been derived, using the Hipparcos parallax of WW Aur and published ultraviolet, optical and infrared fluxes, and are 7960+/-420 and 7670+/-410K. The masses, radii and effective temperatures of WW Aur are only matched by theoretical evolutionary models for a fractional initial metal abundance, Z, of approximately 0.06 and an age of roughly 90Myr. This seems to be the highest metal abundance inferred for a well-studied detached eclipsing binary, but we find no evidence that it is related to the metallic-lined nature of the stars. The circular orbit of WW Aur is in conflict with the circularization timescales of both the Tassoul and the Zahn tidal theories and we suggest that this is due to pre-main-sequence evolution or the presence of a circular orbit when the stars were formed.
- ID:
- ivo://nasa.heasarc/flarestars
- Title:
- UVCet-typeFlareStars&RelatedObjectsCatalog
- Short Name:
- FlareStars
- Date:
- 21 Feb 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the catalog of the UV Cet-type flare stars and related objects in the solar vicinity. This new catalog of flare stars includes 463 objects. It contains astrometric, spectral and photometric data as well as information on the infrared, radio and X-ray properties and general stellar parameters. This table was created by the HEASARC in October 2005 based on the merger of 3 CDS tables (table1.dat, table2.dat and atble3.dat) from the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+AS/139/555/">CDS Catalog J/A+AS/139/555/</a> . This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/ApJ/754/83
- Title:
- UV continuum for z~4-7 star-forming galaxies
- Short Name:
- J/ApJ/754/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Ultra-deep Advanced Camera for Surveys (ACS) and WFC3/IR HUDF+HUDF09 data, along with the wide-area GOODS+ERS+CANDELS data over the CDF-S GOODS field, are used to measure UV colors, expressed as the UV-continuum slope {beta}, of star-forming galaxies over a wide range of luminosity (0.1L*_z=3_ to 2L*_z=3_) at high redshift (z~7 to z~4). {beta} is measured using all ACS and WFC3/IR passbands uncontaminated by Ly{alpha} and spectral breaks. Extensive tests show that our {beta} measurements are only subject to minimal biases. Using a different selection procedure, Dunlop et al. (2012MNRAS.420..901D) recently found large biases in their {beta} measurements. To reconcile these different results, we simulated both approaches and found that {beta} measurements for faint sources are subject to large biases if the same passbands are used both to select the sources and to measure {beta}. High-redshift galaxies show a well-defined rest-frame UV color-magnitude (CM) relationship that becomes systematically bluer toward fainter UV luminosities. No evolution is seen in the slope of the UV CM relationship in the first 1.5 Gyr, though there is a small evolution in the zero point to redder colors from z~7 to z~4. This suggests that galaxies are evolving along a well-defined sequence in the L_UV_-color ({beta}) plane (a "star-forming sequence"?). Dust appears to be the principal factor driving changes in the UV color {beta} with luminosity. These new larger {beta} samples lead to improved dust extinction estimates at z~4-7 and confirm that the extinction is essentially zero at low luminosities and high redshifts. Inclusion of the new dust extinction results leads to (1) excellent agreement between the star formation rate (SFR) density at z~4-8 and that inferred from the stellar mass density; and (2) to higher specific star formation rates (SSFRs) at z>~4, suggesting that the SSFR may evolve modestly (by factors of ~2) from z~4-7 to z~2.
- ID:
- ivo://CDS.VizieR/J/ApJ/793/115
- Title:
- UV-continuum slopes beta for z~4-8 galaxies
- Short Name:
- J/ApJ/793/115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We measure the UV-continuum slope {beta} for over 4000 high-redshift galaxies over a wide range of redshifts z~4-8 and luminosities from the HST HUDF/XDF, HUDF09-1, HUDF09-2, ERS, CANDELS-N, and CANDELS-S data sets. Our new {beta} results reach very faint levels at z~4 (-15.5 mag: 0.006 L_z=3_^*^), z~5 (-16.5 mag: 0.014 L_z=3_^*^), and z~6 and z~7 (-17 mag: 0.025 L_z=3_^*^). Inconsistencies between previous studies led us to conduct a comprehensive review of systematic errors and develop a new technique for measuring {beta} that is robust against biases that arise from the impact of noise. We demonstrate, by object-by-object comparisons, that all previous studies, including our own and those done on the latest HUDF12 data set, suffered from small systematic errors in {beta}. We find that after correcting for the systematic errors (typically {Delta}{beta}~0.1-0.2) all {beta} results at z~7 from different groups are in excellent agreement. The mean {beta} we measure for faint (-18 mag: 0.1L_z=3_^*^) z~4, z~5, z~6, and z~7 galaxies is -2.03+/-0.03+/-0.06 (random and systematic errors), -2.14+/-0.06+/-0.06, -2.24+/-0.11+/-0.08, and -2.30+/-0.18+/-0.13, respectively. Our new {beta} values are redder than we have reported in the past, but bluer than other recent results. Our previously reported trend of bluer {beta}'s at lower luminosities is confirmed, as is the evolution to bluer {beta}'s at high redshifts. {beta} appears to show only a mild luminosity dependence faintward of M_UV, AB_~-19 mag, suggesting that the mean {beta} asymptotes to ~-2.2 to -2.4 for faint z>=4 galaxies. At z~7, the observed {beta}'s suggest non-zero, but low dust extinction, and they agree well with values predicted in cosmological hydrodynamical simulations.
