- ID:
- ivo://CDS.VizieR/J/A+A/441/631
- Title:
- {Delta}a photometry of CP stars
- Short Name:
- J/A+A/441/631
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have summarized all {Delta}a measurements for galactic field stars (1474 objects) from the literature published over more than two decades. These measurements were, for the first time, compiled and homogeneously analyzed. The {Delta}a intermediate band photometric system samples the depth of the 5200{AA} flux depression by comparing the flux at the center with the adjacent regions with bandwidths of 110{AA} to 230{AA}. Because it was slightly modified over the last three decades, we checked for systematic trends for the different measurements but found no correlations whatsoever. The {Delta}a photometric system is most suitable to detecting magnetic chemically peculiar (CP) stars with high efficiency, but is also capable of detecting a small percentage of non-magnetic CP objects. Furthermore, the groups of (metal-weak) lambda Bootis, as well as classical Be/shell stars, can be successfully investigated. In addition, we also analyzed the behaviour of supergiants (luminosity class I and II). On the basis of apparent normal type objects, the correlation of the 3sigma significance limit and the percentage of positive detection for all groups was derived.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+AS/130/455
- Title:
- Delta-a photometry of southern B & A bright stars
- Short Name:
- J/A+AS/130/455
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table 2 lists the HR and HD numbers, the run in which the observations were obtained (sometimes several observations per run and/or on several runs, a, Delta a absolute and expressed in units of the average standard deviation of normal stars from the normality line, b-y and its dereddened quantity (b-y)_0, m_1, the spectral types from the BS Catalogue and the Michigan spectral survey (where available), then a column which indicates whether the object was used for the construction of the normality line (N) or entered the group of double stars (D), and finally the peculiarity group to which the star belongs (Preston's CP1-4, {lambda} Boo, {delta} Del, emission line objects E, supergiants SG and a Barium star Ba). For a description of the {DELTA}a photometric system, see e.g. <GCPD/75>
- ID:
- ivo://CDS.VizieR/J/A+AS/129/9
- Title:
- Delta Sct stars in Praesepe
- Short Name:
- J/A+AS/129/9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photoelectric photometry of seven Delta Scuti stars in Praesepe was secured. Three of them were observed simultaneously at observatories located at different longitudes. Period analysis has been carried out for each star with different computing packages and the results compared to those in the literature. Their physical characteristics have been determined from the Stromgren photometry and theoretical and empirical calibrations.
- ID:
- ivo://CDS.VizieR/J/other/JAD/24.1
- Title:
- Delta Scuti Network photometric data. 4 CVn
- Short Name:
- J/other/JAD/24.1
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Nearly 1000 nights of high-precision photometry of the delta Scuti variable 4 CVn were obtained from 1966 to 2012. These data led to the discovery of 64+ frequencies of pulsation together with systematic changes in amplitudes and small period changes on a timescale of decades. This paper presents the previously unpublished data.
1565. Delta Scuti stars
- ID:
- ivo://CDS.VizieR/J/A+AS/144/469
- Title:
- Delta Scuti stars
- Short Name:
- J/A+AS/144/469
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An extensive and up-dated list of {delta} Sct stars is presented here. More than 500 papers, published during the last few years, have been revised and 341 new variables have been added to our last list, six years ago. This catalogue is intended to be a comprehensive review on the observational characteristics of all the {delta} Sct stars known until now, including stars contained in earlier catalogues together with other new discovered variables, covering information published until January 2000. In summary, 636 variables, 1149 references and 182 individual notes are presented in this new list.
- ID:
- ivo://CDS.VizieR/J/PASP/106/1120
- Title:
- Delta Scuti variables. II. DY Her
- Short Name:
- J/PASP/106/1120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the second paper in a series on large-amplitude delta Scuti stars intended to determine Baade-Wesselink radii and luminosities with precision. The first paper (Wilson et al., 1993PASP..105..809W) discussed our method of analysis and its application to EH Librae; in this we discuss the observations and analysis of DY Herculis. Optical and infrared photometry and cross-correlated radial-velocity data have been obtained and analyzed. Fourier representations for the UBVRIJHK light curves and for the radial-velocity curves were used to derive a value for the minimum radius for each of 60 combinations of flux and color index. From these we adopt a mean value for the minimum radius of R_min_=2.77+/-0.20R_{sun}_. When combined with effective temperatures from Breger et al. (1978PASP...90..754B), we find a mean bolometric luminosity of <L_B_>=21.70L_{sun}_ and a mean absolute magnitude of <M_B_>=1.41. The radial excursion is 0.149R_{sun}_. We use the same procedure to improve our results for EH Librae, deriving R_min_ for each of 42 combinations of flux and color index, and obtain mean values of R_min_=2.62+/-0.19R_{sun}_, <L_B_>=24.56L_{sun}_ and <M_B_>=1.27.
- ID:
- ivo://CDS.VizieR/VII/234
- Title:
- DENIS catalog of galaxies
- Short Name:
- VII/234
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new, extended and improved version of the provisional I-band catalog of DENIS galaxies. Galaxies not cross-identified with already known galaxies have been visually controlled using the DSS1 images and, occasionally, the coordinates were remeasured. The typical accuracy of coordinates is about 2". The typical error on I-band magnitude is about 0.2mag. The final catalog gives the most common names, the J2000 coordinates, the I-band magnitude, the diameter, the axis ratio and the position angle for about 43000 galaxies. It covers roughly 67% of the southern hemisphere. It is homogeneously sampled up to I=14.5 mag. The data are also available via the LEDA database.
- ID:
- ivo://CDS.VizieR/II/228A
- Title:
- DENIS Catalogue toward Magellanic Clouds (DCMC)
- Short Name:
- II/228A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the first version of a complete near-IR point source catalogue towards the Magellanic Clouds extracted from the data obtained with the DEep Near Infraread Survey of the Southern Sky (DENIS). The catalogue covers an area of 19.87x16 square degrees centered on (05:27:20-69:00:00) for the Large Magellanic Cloud (LMC), and 14.7x10 square degrees centered on (01:02:40-73:00:00) for the Small Magellanic Cloud (SMC). It contains the sources detected in at least 2 of the 3 photometric bands I (Gunn-i centered at 0.8{mu}m), J (centered at 1.25{mu}m), and K_s_ (centered at 2.15{mu}m). The spatial resolution is 1" in I and 3" in the J and K bands, and the limiting magnitudes are I=18, J=16 and K_s_=14. 70% of the detected sources are real members of the Magellanic Clouds, and consist mainly of red giants, asymptotic giant branch stars and supergiants.
- ID:
- ivo://CDS.VizieR/J/A+A/387/1
- Title:
- DENIS galaxies behind the Milky Way
- Short Name:
- J/A+A/387/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A search has been undertaken at Lyon Observatory to identify, by eye, galaxy candidates at galactic latitudes lower than +/-15 degrees on the DENIS J and K-band images. This paper presents a list of 2028 objects that were serendipitously detected throughout the DENIS survey. Cross-identification with galaxy entries in the LEDA Database has been performed. Comparison with the second release of the 2MASS survey led to a satisfactory agreement of J band magnitudes (std. dev.=0.3mag). The distribution of galaxy candidates along the Galactic Plane shows a concentration near the galactic longitude l=305deg. As a by product of this inspection of J and K images some interesting galactic objects were found (star clusters and nebulae).
- ID:
- ivo://CDS.VizieR/J/A+A/401/959
- Title:
- 35 DENIS late-M dwarfs between 10 and 30pc
- Short Name:
- J/A+A/401/959
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper reports updated results on our systematic mining of the DENIS database (<B/denis>) for nearby very cool M-dwarfs (M6V-M8V, 2.0=<I-J=<3.0, photometric distance within 30pc), initiated by Phan-Bao et al. (2001, Cat. <J/A+A/380/590>, hereafter Paper I). We use M dwarfs with well measured parallaxes (HIP, GCTP,...) to calibrate the DENIS (M_I_, I-J) colour-luminosity relationship. The resulting distance error for single dwarfs is about 25%. Proper motions, as well as B and R magnitudes, were measured on archive Schmidt plates for those stars in the DENIS database that meet the photometric selection criteria. We then eliminate the giants by a Reduced Proper Motion cutoff, which is significantly more selective than a simple proper motion cutoff. It greatly reduces the selection bias against low tangential velocity stars, and results in a nearly complete sample. Here we present new data for 62 red dwarf candidates selected over 5700 square degrees in the DENIS database. 26 of those originate in the 2100 square degrees analysed in Paper I, with improved parameters here, and 36 were found in 3600 additional square degrees. 25 of those are new nearby dwarfs. In addition we cross-identified the NLTT and DENIS catalogues to find 15 similar stars, in parts of the sky not yet covered by the colour-selected search. We present distance and luminosity estimates for these 15 stars, 10 of which are newly recognized nearby dwarfs. A similar search in Paper I produced 4 red dwarf candidates, and we have thus up to now identified a total of 35 new nearby late-M dwarfs.
