Related papers: OB Associations
Elemental abundances of carbon, nitrogen, oxygen, magnesium, aluminum, and silicon are presented for a sample of twelve rapidly rotating OB star (v sin i > 60 km s^-1) members of the Cep OB2, Cyg OB3 and Cyg OB7 associations. The abundances…
The previously known, 6-yr spectroscopic binary HR 6046 has been speculated in the past to contain a compact object as the secondary. A recent study has re-determined the orbit with great accuracy, and shown that the companion is an evolved…
We report the detections of low-mass companions to five M and L dwarfs within 10 pc of the Sun using the Hubble Space Telescope (HST) Near-Infrared Camera and Multi-Object Spectrometer (NICMOS). Follow-up observations using the HST Advanced…
The latest results in the research of forming planetary systems have led several authors to compile a sample of candidates for searching for planets in the vicinity of the sun. Young stellar associations are indeed excellent laboratories…
The Per OB1 association, which contains the remarkable double cluster h and chi Per, is unusual in not having a giant molecular cloud in its vicinity. We show from Hipparcos data that the luminous members of this association exhibits a bulk…
Taking advantage of an improved genetic optimization algorithm for fitting unconstrained Kepler orbits to the Hipparcos intermediate astrometric data, we obtain additional orbital solutions for 81 Hipparcos stars with previous stochastic…
We have developed a method to calculate the fundamental parameters of the vertical structure of the Galaxy in the solar neighborhood from trigonometric parallaxes alone. The method takes into account Lutz-Kelker-type biases in a…
We present a large-scale, volume-limited companion survey of 245 late-K to mid-M (K7-M6) dwarfs within 15 pc. Infrared adaptive optics (AO) data were analysed from the Very Large Telescope, Subaru Telescope, Canada-France-Hawaii Telescope,…
We study the relation between halo concentration and mass (c-M relation) using the Seventh and Eighth Data Release of the Sloan Digital Sky Survey (SDSS DR7 and DR8) galaxy catalogue. Assuming that the satellite galaxies follow the…
We report the initial results of a large-scale optical-near infrared survey to extend the known young population of the entire Orion star-forming region down to the substellar domain. Using deep optical I-band photometry and data from the…
Our star-count analysis of the Two Micron All Sky Survey point sources resulted in an identification of the star cluster G144.9+0.4. The cluster was found, but not characterized, by Glushkova et al. We show that the cluster is physically…
OB stars are crucial for our understanding of Galactic structure, star formation, stellar feedback and multiplicity. In this paper we have compiled a census of all OB stars within 1 kpc of the Sun. We performed evolutionary and atmospheric…
Over the past nine years, the Kepler and K2 Missions have carried out high precision photometric monitoring of more than half a million stars. Among these targets are 29 clusters and associations, with ages from 1 Myr to over 11 Gyr. We…
Within the molecular clouds of the Camelopardis OB1 association exists a region previously noted as one subgroup. However, bulk clustering from Gaia astrometry has recently shown three distinctive kinematically coherent groups, all found in…
We use observational properties of galaxies accumulated in the Updated Nearby Galaxy Catalog to derive a dark matter mass of luminous galaxies via motions of their companions. The data on orbital-to-stellar mass ratio are presented for 15…
We present 3-dimensional kinematical observations of the massive OB association Cygnus OB2 to identify the mechanisms responsible for disrupting young star clusters. The picture revealed by these observations is of a highly-substructured,…
Five new objects with proper motions between 1.0 arcsec/yr and 2.6 arcsec/yr have been discovered via a new RECONS search for high proper motion stars utilizing the SuperCOSMOS Sky Survey. The first portion of the search, discussed here, is…
We report about an ongoing photometric and spectroscopic monitoring survey of about 250 O- and 540 B-type stars in the southern Milky Way with the aim to determine the fraction of close binary systems as a function of mass and to determine…
We search for the astrometric signatures of planets and brown dwarfs known from radial velocity surveys in the improved Hipparcos intermediate astrometric data provided by van Leeuwen (2007a). Our aim is to put more significant constraints…
We search for stellar and substellar companions of young nearby stars to investigate stellar multiplicity and formation of stellar and substellar companions. We detect common proper-motion companions of stars via multi-epoch imaging. Their…