Recent surveys indicate that planets in binary systems are more abunda- nt than previously thought, which is in agreement with theoretical work on disc dynamics and planet formation in binaries. So far, most observational surveys, however, have focused on short-period planets in binaries, thus little is known about the occurrence rates of planets on longer periods (>10au). In order to measure the abundance and physical characteristics of wide-orbit giant exoplanets in binary systems, we have designed the 'VIsual Binary Exoplanet survey with Sphere' (VIBES) to search for planets in visual binaries. It uses the SPHERE instrument at VLT to search for planets in 23 visual binary and four visual triple systems with ages of <145Myr and distances of <150pc. We used the IRDIS dual-band imager on SPHERE to acquire high-contrast images of the sample targets. For each binary, the two components were observed at the same time with a coronagraph masking only the primary star. For the triple star, the tight components were treated as a single star for data reduction. This enabled us to effectively search for companions around 50 individual stars in binaries and four binaries in triples. We derived upper limits of <13.7% for the frequency of sub-stellar companions around primaries in visual binaries, <26.5% for the fraction of sub-stellar companions around secondaries in visual binaries, and an occurrence rate of <9.0% for giant planets and brown dwarfs around either component of visual binaries. We have combined our observations with literature measurements to astrometrically confirm, for the first time, that 20 binaries and two triple systems, which were previously known, are indeed physically bound. Finally, we discovered a third component of the binary HD 121336. The upper limits we derived are compatible with planet formation through the core accretion and the gravitational instability processes in binaries. These limits are also in line with limits found for single star and circumbinary planet search surveys.
The paper gives orbits and masses for some 200 nearby visual binaries, as derived from combining ground-based and Hipparcos data. Table 6 gives identifications and notes, and points to the detailed data in Table 1 (short-P systems with mass-ratio from the Hipparcos observations), Table 3 (mass-uncertainty below 10%) or Table 4 (mass-uncertainty above 10%).
The results of a BVR photometry observations are presented for multiple stars visual subsystems (table2.dat). The objects (table1.dat) were observed in 1996 with the 60 cm and 1 m telescopes at Maidanak Observatory (Uzbekistan) by aperture and scanning photometers. The positional parameters and physical relation of visual subsystems are also given (table4.dat).
This catalogue is the only complete list of all known double and multiple systems (18644) of which at least one component was identified in the Hipparcos final catalog in July 1997 (Cat. <I/239>), including the 2994 systems newly discovered by the satellite, as well as the 155 new astrometric orbital pairs also discovered by the satellite (Dommanget, 2000Obs...120..202D), and also the 38 new astrometric binaries components of known systems. It may be considered as a subset of the CCDM as existing in 1998 of which a first edition appeared in 1994 (Cat. <I/211>), and of which a second edition containing more than 45,000 systems is being prepared for publication. Consequently, the format of this list is that of the CCDM for which all information may be found in the introduction of its 1994 published version (as file I/211/ccdm.doc) The format of this catalogue is the same as the CCDM (Cat. <I/211>)
A total of 1000 new classifications are given for stars brighter than B=8.0mag in the Aitken double star catalog. The classifications supplement 865 classifications obtained in 1981 and 1984. Among the newly discovered stars are 12 new Ap stars, eight Lambda Bootis stars, one Ba II star, and 60 Am stars. A detailed list of the new classifications is given.
We have visually examined 12 Palomar red plates for galaxies at low Galactic latitude b, where the Supergalactic Plane (SGP) is crossed by the Galactic Plane (GP), at Galactic longitude l~135deg. The catalogue consists of 2575 galaxy candidates, of which 462 have major axis diameter d>=0.8arcmin (uncorrected for extinction). Galaxy candidates can be identified down to |b|~0deg. One of our galaxy candidates (J24=Dwingeloo 1) has recently been discovered independently at 21cm by Kraan-Korteweg et al. as a nearby galaxy. Comparisons with structures seen in the IRAs and UGC catalogues are made. We compare the success rate of identifying galaxies using the IRAS Point Source Catalogue under different colour selection criteria. The criteria that require both the 60- and 100-{mu}m fluxes to be of high quality have the highest probability of selecting a galaxy (with d>=0.6arcmin), but at the expense of selecting a smaller number of galaxies in total.
Our photometric survey of Local Group galaxies, using a four filter technique based on the method of Wing (1971, Proc. Conf. Late-Type Stars, ed. G.W. Lockwood and H.M. Dyck, KPNO Contribution 554, 145) allows the identification and subsequent characterization of their late-type stellar content. Two narrow band filters centred on molecular bands of TiO and CN allow us to distinguish between AGB stars of different chemistries [M-type (O-rich) and C-type (C-rich)]. The faint dwarf spheroidal galaxy And II, a member of the M 31 subgroup, was surveyed. From photometry in V and i as well as in the narrow band filters TiO and CN we were able to identify 7 new AGB carbon stars, to derive their mean absolute <Mi> and bolometric magnitude Mbol, their luminosity function, and their spatial distribution. We are unable to establish the true C/M ratio because the few M stars of And II are overwhelmed by foreground Galactic M st
We have calibrated four major ground-based photometric systems with respect to the Hubble Space Telescope (HST) absolute flux scale, which is defined by Vega and four fundamental DA white dwarfs. These photometric systems include the Johnson-Kron-Cousins UBVRI, the Stroemgren uvby filters, the Two Micron All Sky Survey JHKs, and the Sloan Digital Sky Survey ugriz filters. Synthetic magnitudes are calculated from model white dwarf spectra folded through the published filter response functions; these magnitudes in turn are absolutely calibrated with respect to the HST flux scale. Effective zero-magnitude fluxes and zero-point offsets of each system are determined. In order to verify the external observational consistency, as well as to demonstrate the applicability of these definitions, the synthetic magnitudes are compared with the respective observed magnitudes of larger sets of DA white dwarfs that have well-determined effective temperatures and surface gravities and span a wide range in both of these parameters.
We report on new aspects of the star-forming region S235AB revealed through high-resolution observations at radio and mid-infrared wavelengths. Using the Very Large Array, we carried out sensitive observations of S235AB in the cm continuum (6, 3.6, 1.3, and 0.7) and in the 22GHz water maser line. These were complemented with Spitzer Space Telescope Infrared Array Camera archive data to clarify the correspondence between radio and IR sources. We made also use of newly presented data from the Medicina water maser patrol, started in 1987, to study the variability of the water masers found in the region.
