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1771. Edinburgh-Cape Blue Object Survey. III.
ID:
ivo://CDS.VizieR/J/MNRAS/431/240
Title:
Edinburgh-Cape Blue Object Survey. III.
Short Name:
J/MNRAS/431/240
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Edinburgh-Cape Blue Object Survey seeks to identify point sources with an ultraviolet excess. Results for zone 2 of the survey are presented here, covering that part of the South Galactic Cap between 30 and 40{deg} from the Galactic plane and south of about -12.3{deg} of declination. Edinburgh-Cape zone 2 comprises 66 UK Schmidt Telescope fields covering about 1730sq.deg, in which we find some 892 blue objects, including 423 hot subdwarfs (~47%); 128 white dwarfs (14%); 25 cataclysmic variables (~3%); 119 binaries (~13%), mostly composed of a hot subdwarf and a main-sequence F or G star; 66 horizontal branch stars (~7%) and 48 "star-like" extragalactic objects (~5%). A further 362 stars observed in the survey, mainly low-metallicity F- and G-type stars, are also listed. Both low-dispersion spectroscopic classification and UBV photometry are presented for almost all of the hot objects and either spectroscopy or photometry (or both) for the cooler ones.
1772. Edinburgh-Cape Blue Object Survey. Zone 1.
ID:
ivo://CDS.VizieR/J/MNRAS/287/867
Title:
Edinburgh-Cape Blue Object Survey. Zone 1.
Short Name:
J/MNRAS/287/867
Date:
21 Oct 2021
Publisher:
CDS
Description:
Results for Zone 1 of the Edinburgh-Cape (EC) Blue Object Survey are presented. This zone covers that part of the North Galactic Cap more than ~30{deg} from the Galactic plane and south of about -12.3{deg} declination (although a few fields north of this declination are included). The zone effectively complements the Palomar-Green Survey in the North Galactic Cap, although the EC Survey should be more complete to a fainter limit (B=16.5mag) and to somewhat redder stars (U-B bluer than about -0.4). Zone 1 covers approximately 1560{deg}^2^ and contains 675 blue objects far which we list equatorial coordinates accurate to ~1arcsec, UBV photoelectric photometry, and spectral types determined from moderate-dispersion (100{AA}/mm) spectrograms.
1773. Edinburgh-Cape Blue Object Survey. Zones 4-6
ID:
ivo://CDS.VizieR/J/MNRAS/459/4343
Title:
Edinburgh-Cape Blue Object Survey. Zones 4-6
Short Name:
J/MNRAS/459/4343
Date:
21 Oct 2021
Publisher:
CDS
Description:
Results for the remaining zones of the Edinburgh-Cape (EC) Blue Object survey are presented. These are incomplete, but lie in that part of the South Galactic Cap between 50deg and 90deg from the Galactic plane and south of about -12.3{deg} of declination. This part of the survey comprises 79 UK Schmidt Telescope fields covering about 2150deg^2^, in which we find 536 blue objects - including hot subdwarfs (~33 per cent), white dwarfs (~30 per cent), binaries (~12 per cent), cataclysmic variables (~1.5 per cent) and some 'star-like' galaxies (~12 per cent). A further 254 stars observed in the survey, mainly low-metallicity F- and G-type stars, are also listed. Low-dispersion spectroscopic classification is given for all the hot objects and UBV photometry for most of them. Either spectroscopy or photometry is listed for the cooler types.
1774. EE Aqr UBV light curves
ID:
ivo://CDS.VizieR/J/AJ/139/1486
Title:
EE Aqr UBV light curves
Short Name:
J/AJ/139/1486
Date:
21 Oct 2021
Publisher:
CDS
Description:
EE Aqr is a 7.9mag Algol variable with a 12hr orbital period. The Wilson-Devinney program is used to simultaneously solve 11 previously published light curves together with two existing radial velocity curves. The resulting masses are M_1_=2.24+/-0.13M_{sun}_ and M_2_=0.72+/-0.04M_{sun}_, and the radii are R_1_=1.76+/-0.03R_{sun}_ and R_2_=1.10+/-0.02R_{sun}_. The system has the lower-mass component completely filling its Roche lobe. Its distance from Hipparcos observations is 112+/-10pc. An improved ephemeris is derived, and no deviations in the period over time were seen. Light and velocity curve parameters, orbital elements, and absolute dimensions are presented, plus a comparison is made with previous solutions.
1775. EE Cam, FG Vir and 44 Tau light curves
ID:
ivo://CDS.VizieR/J/other/JAD/25.1
Title:
EE Cam, FG Vir and 44 Tau light curves
Short Name:
J/other/JAD/25.1
Date:
22 Feb 2022
Publisher:
CDS
Description:
The three delta Scuti pulsators EE Cam, FG Vir and 44 Tau are of special interest because their pulsation properties are different from those expected from the low rotational velocities indicated by spectroscopic measurements. This paper presents the previously unpublished high-precision photometric data obtained by the Delta Scuti Network during 780 nights.
1776. EFAR photometric data
ID:
ivo://CDS.VizieR/J/MNRAS/292/499
Title:
EFAR photometric data
Short Name:
J/MNRAS/292/499
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present R-band CCD photometry for 776 galaxies observed in the EFAR (Elliptical FAR away) project. The photometry is compared with photoelectric data, showing that a common zero-point good to better than 1% and a precision of 0.03mag per zero-point have been achieved. We give the circularly averaged surface brightness profiles and the photometric parameters of the 762 program galaxies, D(n) diameters (at 20.5mag/arcsec^2^), half-luminosity radii Re, total magnitudes m_T_, and average effective surface brightnesses <SBe>. More than 80% of the profiles have a global S/N ratio larger than 300. The extrapolation needed to derive total magnitudes is less than 10% for 80% of the fits. More than 80% of the galaxies have mean effective surface brightness larger than the observed sky brightness. In 90% of the profiles the estimate of the contamination of the sky by the galaxy light is less than 1%. We derive total magnitudes and half-luminosity radii to better than 0.15mag and 25%, respectively, for 90% of our sample. In contrast, external comparisons show that data in the literature can be strongly affected by systematic errors due to large extrapolations, small radial range, sky subtraction errors, seeing effects, and the use of a simple R^1/4^ fit. The resulting errors can easily amount to more than 0.5mag in the total magnitudes and 50% in the half-luminosity radii.
1777. Effective temperature of B stars
ID:
ivo://CDS.VizieR/J/A+A/444/941
Title:
Effective temperature of B stars
Short Name:
J/A+A/444/941
Date:
21 Oct 2021
Publisher:
CDS
Description:
We establish an empirical effective temperature calibration of main sequence, luminosity class V to III B-type stars for the Delta a photometric system which was originally developed to detect magnetic chemically peculiar objects of the upper main sequence (early B-type to early F-type) at 5200A. However, this system provides the index g1-y which shows an excellent correlation with B-V as well as b-y and can be used as an indicator of the effective temperature. This is supplemented by a very accurate color-magnitude diagram, y or V versus g1-y, which can be used, for example, to determine the reddening, distance and age of an open cluster. This makes the Delta a photometric system an excellent tool to investigate the HR diagram in more detail. Using the reddening-free parameters and already established calibrations within the Stromgren uvbybeta, Geneva 7-color and Johnson UBV systems, a polynomial fit of third degree for the averaged effective temperatures to the individual (g1-y)0 values was derived. For this purpose, data from the literature as well as new observations were taken resulting in 225 suitable bright normal B-type objects. The statistical mean of the error for this sample is 238K which is sufficient to investigate the HRD of distant galactic open clusters as well as extragalactic aggregates in the future.
1778. Effective temperature of 30 Dor population
ID:
ivo://CDS.VizieR/J/A+A/443/851
Title:
Effective temperature of 30 Dor population
Short Name:
J/A+A/443/851
Date:
21 Oct 2021
Publisher:
CDS
Description:
The star-formation history and IMF of the field population of the 30 Doradus super-association is determined using Wide Field Imager photometry. The cluster NGC 2070 and the OB association LH104 are also studied and used for comparison. The star-formation history of the 30~Doradus super-association appears to be characterized by a large increase in star-formation activity 10Myr to 20Myr ago. This seems to be the case across the whole eastern half of the LMC as demonstrated by the ages of stellar populations as far away as 30 Doradus and Shapley's Constellation III. Star-formation appears to be occurring at a constant rate in the field and in loose associations, and in bursts in the clusters. The field IMF is found to have almost the exact Salpeter slope in the range 7M_{sun}_<=M<=40M_{sun}_, at odds with previous claims. We find that, for objects with more complex star-formation histories, Be stars and selective incompleteness strongly affect the determination of the IMF for M>40M_{sun}_, naturally explaining the observed deviation of the high mass IMF slope from the Salpeter value.The present work supports the idea of a universal IMF.
1779. Effective temperature of metal-poor A-type stars
ID:
ivo://CDS.VizieR/J/A+A/391/1039
Title:
Effective temperature of metal-poor A-type stars
Short Name:
J/A+A/391/1039
Date:
21 Oct 2021
Publisher:
CDS
Description:
Effective temperatures (T_eff_) can be determined from (V-J)_0_, (V-H)_0_ and (V-K)_0_ colours that are derived from 2MASS magnitudes. This gives another way to estimate the T_eff_ of faint blue halo stars (V<~15) whose temperatures are now usually deduced from (B_V)_0_. Transformations (adapted from Carpenter, 2001AJ....121.2851C) are used to change colours derived from the 2MASS data to the Johnson system. T_eff_ is then derived from these colours using an updated Kurucz model. Tables are given to derive T_eff_ as a function of (V-J)_0_, (V-H)_0_ and (V-K)_0_ for a variety of metallicities and suitable for blue horizontal branch and main sequence stars. The temperatures obtained in this way are compared with those in the recent literature for various stars with 5<=V<=15 and T_eff_ in the range 6500 to 9500K; systematic differences are ~100K. An exception is the sample of BHB stars observed by Wilhelm et al. (1999, Cat. <J/AJ/117/2329>) whose T_eff_ are significantly cooler than those we derive by an amount that increases with increasing temperature. Description:
1780. Effective temperatures and radii of stars
ID:
ivo://CDS.VizieR/J/A+A/450/735
Title:
Effective temperatures and radii of stars
Short Name:
J/A+A/450/735
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper presents a method to determine effective temperatures, angular semi-diameters and bolometric corrections for population I and II FGK type stars based on V and 2MASS IR photometry. Accurate calibration is accomplished by using a sample of solar analogues, whose average temperature is assumed to be equal to the solar effective temperature of 5777K.