- 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.
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- 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.
- 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.
- 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.
- 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.
- ID:
- ivo://CDS.VizieR/J/AN/321/277
- Title:
- Effective temperatures of K-M giants
- Short Name:
- J/AN/321/277
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A high-resolution spectroscopic survey in the 6380-6460{AA} region of 224 slowly-rotating M-K class III giants is presented. Spectral line-depth ratio are calibrated against effective temperature obtained from B-V and V-I color indices in the range 3200-7500K (M6-A9). A table of polynomial coefficients for 12 line-ratio-Teff relations can be used to derive Teff of F-M stars to within 33K (rms), and of early-F and mid-to-late M stars to within 77-106K (rms).
- ID:
- ivo://CDS.VizieR/J/AJ/156/83
- Title:
- Effect of stellar companions on planetary systems
- Short Name:
- J/AJ/156/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Kepler light curves used to detect thousands of planetary candidates are susceptible to dilution due to blending with previously unknown nearby stars. With the automated laser adaptive optics instrument, Robo-AO, we have observed 620 nearby stars around 3857 planetary candidates host stars. Many of the nearby stars, however, are not bound to the KOI. We use galactic stellar models and the observed stellar density to estimate the number and properties of unbound stars. We estimate the spectral type and distance to 145 KOIs with nearby stars using multi-band observations from Robo-AO and Keck-AO. Most stars within 1" of a Kepler planetary candidate are likely bound, in agreement with past studies. We use likely bound stars and the precise stellar parameters from the California Kepler Survey to search for correlations between stellar binarity and planetary properties. No significant difference between the binarity fraction of single and multiple-planet systems is found, and planet hosting stars follow similar binarity trends as field stars, many of which likely host their own non-aligned planets. We find that hot Jupiters are ~4x more likely than other planets to reside in a binary star system. We correct the radius estimates of the planet candidates in characterized systems and find that for likely bound systems, the estimated planetary radii will increase on average by a factor of 1.77, if either star is equally likely to host the planet. Lastly, we find the planetary radius gap is robust to the impact of dilution.
- ID:
- ivo://CDS.VizieR/J/MNRAS/122/363
- Title:
- Eggen PV photometry in NGC 7492
- Short Name:
- J/MNRAS/122/363
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometry of NGC 7492, a very faint, well resolved cluster, shows that it has a colour-magnitude relation similar in form to that of a typical globular cluster. A well defined but sparsely populated red giant branch is present, along with a horizontal branch, blue stars, and variables. The distance modulus, 17.17, and the distance 27.2kpc., are obtained. The colour excess appears to be negligible. The integrated photographic absolute magnitude is -4.84. The star density in the cluster is unusually low, being approximately 0.06 stars per cubic parsec for stars brighter than +2.5 absolute magnitude. For a description of the PV photometric system, see e.g. <GCPD/31>
- ID:
- ivo://CDS.VizieR/J/A+A/462/553
- Title:
- EIS: optical deep public survey
- Short Name:
- J/A+A/462/553
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents new five passbands (UBVRI) optical wide-field imaging data accumulated as part of the DEEP Public Survey (DPS) carried out as a public survey by the ESO Imaging Survey (EIS) project. Out of the 3 square degrees originally proposed, the survey covers 2.75 square degrees, in at least one band (normally R), and 1.00 square degrees in five passbands. The median seeing, as measured in the final stacked images, is 0.97", ranging from 0.75" to 2.0". The median limiting magnitudes (AB system, 2" aperture, 5{sigma} detection limit) are U_AB_=25.65, B_AB_=25.54, V_AB_=25.18, R_AB_=24.8 and I_AB_=24.12mag, consistent with those proposed in the original survey design. The paper describes the observations and data reduction using the EIS Data Reduction System and its associated EIS/MVM library. The quality of the individual images were inspected, bad images discarded and the remaining used to produce final image stacks in each passband, from which sources have been extracted. Finally, the scientific quality of these final images and associated catalogs was assessed qualitatively by visual inspection and quantitatively by comparison of statistical measures derived from these data with those of other authors as well as model predictions, and from direct comparison with the results obtained from the reduction of the same dataset using an independent (hands-on) software system. Finally to illustrate one application of this survey, the results of a preliminary effort to identify sub-mJy radio sources are reported. To the limiting magnitude reached in the R and I passbands the success rate ranges from 66 to 81% (depending on the fields).
- ID:
- ivo://CDS.VizieR/J/A+A/566/A43
- Title:
- EPOCH Project. EROS-2 LMC periodic variables
- Short Name:
- J/A+A/566/A43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The EPOCH (EROS-2 periodic variable star classification using machine learning) project aims to detect periodic variable stars in the EROS-2 light curve database. In order to classify these variables, we first build a training set by compiling known variables in the Large Magellanic Could area from the OGLE and MACHO surveys. We crossmatch these variables with the EROS-2 sources and extract 22 variability features from 28,392 light curves of the corresponding EROS-2 sources. We then use Random Forests to classify the EROS-2 sources in the training set. We design the model to separate not only Delta Scuti stars, RR Lyraes, Cepheids, eclipsing binaries and long-period variables, the "superclasses", but also their subclasses, such as RRab, RRc, RRd and RRe for RR Lyraes, and similarly for the other variable types. We apply the trained model to the entire EROS-2 LMC database containing about 29 million sources and find 117,234 periodic variable candidates. Out of these 117,234 periodic variables, 55,285 have not been discovered by either OGLE or MACHO variability studies. This set comprises 1906 Delta Scuti stars, 6,607 RR Lyraes, 638 Cepheids, 178 Type II Cepheids, 34,562 eclipsing binaries and 11,394 long-period variables.
