- ID:
- ivo://CDS.VizieR/J/A+A/395/823
- Title:
- CCD {Delta}a-photometry of 5 open clusters
- Short Name:
- J/A+A/395/823
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The time scale on which chemical peculiarity in upper main sequence stars begins is unknown. Results from the Hipparcos measurements indicate that the classical chemically peculiar (CP) stars occupy the whole area from the zero age main sequence to the terminal age main sequence. Hubrig et al. (2000ApJ...539..352H) reported that the magnetic fields appear only in stars that have already completed at least approximately 30% of their main sequence life time. Previous observations in the very young Orion OB1 and Scorpio Centaurus associations reveal a percentage of chemically peculiar stars that is significantly smaller (less than 5%) than that of the galactic field (up to 25%). This already indicates that the phenomenon needs at least several Myr to appear. Since no further observations have been published since then, we have observed the five very young (1Myr<Age<25Myr) open clusters Collinder 272, Pismis 20, Lynga 14, NGC 6396 and NGC 6611. Photometry from 250 CCD frames in the three filter Delta a-system results in very low detection limits (0.008 to 0.015mag). We find no single photometrically chemically peculiar candidate in approximately 460 observed cluster members in the five program clusters. From the number of observed objects we deduce upper limits between 0.6% and 2.4% for the incidence of CP stars for the five observed aggregates.The tables presented here include all photometric observations of these five clusters. For a description of the (Delta a) photometric system, see e.g. <GCPD/75>: a = g2 - (g1+y)/2 g1 and g2 centered at 502 and 524nm.
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- ID:
- ivo://CDS.VizieR/J/A+A/385/867
- Title:
- CCD {Delta}a-photometry of 5 open clusters
- Short Name:
- J/A+A/385/867
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In total, more than 550 objects within the fields of five open clusters (NGC 2439, NGC 3960, NGC 6134, NGC 6192 and NGC 6451) were investigated in order to find classical chemically peculiar stars. One bona-fide CP candidate was detected in each of the open clusters NGC 3960, NGC 6192 and NGC 6451. All three objects seem to be members of the corresponding cluster taking the results from our photometry as well as from the literature. For NGC 6192 and NGC 6451 we found widely different interstellar reddening values and therefore distances and ages in the literature. From an analysis of published Johnson UBVRI photometry, we were able to rule out a rather old age for NGC 6451. This is also supported by the finding of one peculiar object in this cluster with spectral type of about A2. Five variable objects within the field of NGC 6134 were detected. The variability exceeds 10 times (or typically 0.03 mag) the standard deviation of the weighted individual measurements. But since our observations were obtained mostly during one hour (typical integration times of five minutes per filter) on several nights within 45 days, no light curves could yet be derived. For this cluster some Am candidates were reported for which we were not able to detect a significant positive {Delta} a-value. For a description of the {Delta}a photometric system, see e.g. <GCPD/75>
- ID:
- ivo://CDS.VizieR/J/A+A/454/171
- Title:
- CCD {Delta}a-photometry of 8 open clusters
- Short Name:
- J/A+A/454/171
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The detection of magnetic chemically peculiar (CP2) stars in open clusters of the Milky Way can be used to study the influence of different galactic environments on the (non-)presence of peculiarities, which has to be taken into account in stellar evolution models. Furthermore it is still unknown if the CP2 phenomenon evolves, i.e. does the strength of the peculiarity feature at 5200{AA} increase or decrease with age. Methods. We have observed eight young to intermediate age open clusters in the {Delta}a photometric system.
- ID:
- ivo://CDS.VizieR/J/AJ/141/21
- Title:
- CCD distance estimates of SCR targets
- Short Name:
- J/AJ/141/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CCD photometric distance estimates of 100 SCR (SuperCOSMOS RECONS) systems with {mu}>=0.18"/yr, 29 of which are new discoveries previously unpublished in this series of papers. These distances are estimated using a combination of new VRI photometry acquired at CTIO and JHK magnitudes extracted from 2MASS. The estimates are improvements over those determined using photographic plate BRI magnitudes from SuperCOSMOS plus JHK, as presented in the original discovery papers. In total, 77 of the 100 systems investigated are predicted to be within 25pc.
- ID:
- ivo://CDS.VizieR/J/A+A/414/23
- Title:
- CCD H{alpha} and R photometry of 334 galaxies
- Short Name:
- J/A+A/414/23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We discuss the selection and observations of a large sample of nearby galaxies, which we are using to quantify the star formation activity in the local Universe. The sample consists of 334 galaxies across all Hubble types from S0/a to Im and with recession velocities of between 0 and 3000km/s. The basic data for each galaxy are narrow band H{alpha}+[NII] and R-band imaging, from which we derive star formation rates, H{alpha}+[NII] equivalent widths and surface brightnesses, and R-band total magnitudes. A strong correlation is found between total star formation rate and Hubble type, with the strongest star formation in isolated galaxies occurring in Sc and Sbc types. More surprisingly, no significant trend is found between H{alpha}+[NII] equivalent width and galaxy R-band luminosity. More detailed analyses of the data set presented here will be described in subsequent papers.
- ID:
- ivo://CDS.VizieR/I/274
- Title:
- CCDM (Catalog of Components of Double & Multiple stars)
- Short Name:
- I/274
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the second edition of the Catalogue of the Components of Double and Multiple stars (CCDM). The first one, of which a detailed description has been given in Communication de l'Observatoire Royal de Belgique, Serie A, 115, 1994, may be found at the CDS under reference <I/211>. The complete description of this second edition is published (in French and English) in "Observations et Travaux", a review edited by the Societe Astronomique de France. A detailed historical sketch of the creation and development of the catalogue -- which served as double star data base for the preparation of the HIpparcos Input Catalogue <I/196> -- has been published in issue 25, pp.29-31 (1999) of this same review. There are no fundamental differences between the two editions: format, presentation and construction are similar. The main difference lies in the important increase of the considered systems of which number expands from 34.031 to 49.325. Few additions exist in the description of the contents of the various columns, and some new codes had to be used for references to astronomical positions, especially related to the introduction of new Hipparcos systems or components to known systems (see the "refpos.dat" file). Concerning the names of the systems in columns 16 to 22, one has also to mention some additions to those given in the INDEX-WDS (C.E.Worley, 1984). They are: AOT = Oss. di Torino ACG = Astr.Cat.Greenw. BAC = P.Bacchus BEW = U.Bastian et al. CRI = F.Crifo DUF = M.Duflot DYL = J. Doyle HDS = Hipparcos JRN = A. Jorissen JKS = M.P.Jenniskens KZA = S.M.Kazeza LMP = P.Lampens LYS = L. Louys MCO = McCormick NYS = O.Nys ONL = Occult. News Letters PWS = Th.Pauwels RSU = M.Rousseau SLE = G.Soulie VHS = P.Verhas Note that: MAL = McAlister in WDS 1984 MCA = McAlister in WDS 1994 Some changes have finally been brought to the names of particular STT and STF systems (App) as shown here, to avoid some confusion that exists with the non (App) systems: --> For STF (App)I, addition of 4000, i.e. STF 4001 instead of STF 1(App)I STF 4002 instead of STF 2(App)I ............... STF 4060 instead of STF 60(App)I --> For STF (App)II, addition of 5000, i.e. STF 5003 instead of STF 3(App)II ............... STF 5012 instead of STF 12(App)II --> For STT (App)I, addition of 4000, i.e. STT 4001 instead of STT 1(App) STT 4005 instead of STT 5(App) ............... STT 4256 instead of STT 256(App)
- ID:
- ivo://CDS.VizieR/I/211
- Title:
- CCDM (Components of Double and Multiple stars)
- Short Name:
- I/211
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The introduction to this catalogue has been the subject of a publication in the "Communications de l'Observatoire Royal de Belgique" (Serie A, number 115). Detailed are: its origins, its aims, its realization, the search of identifiers, the compilation of astrometric data and the related problems as well as the fundamental ties between the CCDM and the HIPPARCOS INPUT CATALOGUE (HIC). It also contains a complete bibliography of the referred papers. The contents of the general catalogue (63,463 systems) is also described as well as the conditions of its availability to the astronomical community and the projects underway for the next edition. For all these items, the user is invited to refer to this publication because hereafter only the format and the contents of the catalogue follow. To identify the systems and their components, we adopted the clever numbering process of the authors of the INDEX consisting in combining the right ascension and declination, respectively limited to 0.1 minute of time and to 1 minute of arc. In order to distinguish the CCDM numbers from the INDEX numbers - in addition to their different equinox: 2000 for the CCDM and 1900 for the INDEX - we adopted the signs + and - instead of the letters N and S for separating the coordinates. Consequently, in the INDEX and in the CCDM, one entry is devoted to a same system but the contrary to the INDEX, where a sub-entry is assigned to each group of two components, whatever the multiplicity of the system may be, the CCDM allows one sub-entry and thus one record per component. The present edition contains only the 34,031 systems (table below, part I) for which an accurate position has been found for at least one component. The catalogue extends thus much over the sample of the somewhat 14,000 systems finally retained for the HIPPARCOS INPUT CATALOGUE and assembled in its Annex 1.
- ID:
- ivo://CDS.VizieR/J/A+AS/111/229
- Title:
- CCD meas. of visual binaries
- Short Name:
- J/A+AS/111/229
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report CCD measurements of 33 visual double stars observed at the 1-meter coude reflector of the Observatorio de Llano del Hato located at Merida, Venezuela. We also present an algorithm to determine the stars' centroids for superimposed images as well as a brief comparison of accuracies attained by the algorithm and the program CENTER of the IRAF package.
- ID:
- ivo://CDS.VizieR/J/A+A/378/954
- Title:
- CCD measurements of double stars
- Short Name:
- J/A+A/378/954
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present measurements of visual double stars made by CCD imaging from 1996 to 1999. In the article, Table 1 contains the measurements of 51 binaries with known orbit. The residuals are discussed in the text. Table 2 presents new measurements for 555 binaries. Angular separation, position angle and magnitude difference are given.
- ID:
- ivo://CDS.VizieR/J/AJ/156/134
- Title:
- CCD measurements of multiple stars at ASV & NAOR
- Short Name:
- J/AJ/156/134
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of classical CCD observations for 371 double or multiple stars (450 pairs) obtained at both, Serbian Astronomical Station on the mountain of Vidojevica (ASV) and Bulgarian National Astronomical Observatory at Rozhen (NAOR) are presented. At ASV the observations were performed with the 0.6 m telescope in the first half of 2016 during 11 nights, and with the newly mounted 1.4 m telescope in the second half of 2016 during 16 nights. At NAOR, the observations were performed with the 2 m telescope during four nights. In this paper, we present 477 measurements (position angle and angular separation) for these 450 pairs. Among them there are 41 pairs with published orbital or linear elements and residuals are given for them. Some pairs have measurements for several epochs. Our observed pairs have angular separations in the interval from 1.60" to 190.30", with a mean angular separation of 14.87" and a median value of 4.34". Two new pairs and linear elements for four pairs which are calculated for the first time are also presented.
