Next: This Work Previous: Rotation Periods of ZAMS Stars . ... There are currently several groups involved in the studies of the rotation periods of PMS stars. ... Overall, there are about 100 rotation periods known for PMS stars. ... Furthermore, the stars with periods near 8 days also tend to have infrared excesses which can be interpreted as arising from disks. ... In the first interpretation, the gap occurs because locking mechanism holds stars at a eight day rotation period. ...

The velocity and mass distribution of clusters of galaxies from the CNOC1 cluster redshift survey . ... The resulting sample is ideally suited for an analysis of the internal velocity and mass distribution of clusters. Previous analyses of this dataset used the Jeans equation to model the projected velocity dispersion profile. However, the results of such an analysis always yield a strong degeneracy between the mass density profile and the velocity dispersion anisotropy profile. ...

... About ATMoB . ... The Observing Committee is starting an Observing Awards Program to promote observing among the membership of the Amateur Telescope Makers of Boston. ... Participant must be a current member of the Amateur Telescope Makers of Boston . ... To qualify for your Observing Award Certificate, turn in your worksheet and drawings to an ATMoB Observing Committee member or observing@atmob.org . ... This Excel sheet has useful macros. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

... Comet SWAN Outburst . ... Star clusters and nebulae abound in the ancient northern constellation Auriga - a region that includes the interesting pair NGC 1931 (lower left) and IC 417. ... The Crab Nebula is cataloged as M1, the first object on Charles Messier's famous list of things which are not comets. ... Star EGGs in the Eagle Nebula . ... Where do stars form? ... But the skilled and careful astronomer also went on to discover star clusters, comets, asteroids, and clusters of galaxies. ...

Next: NICMOS/HST H-band (F160W) Images Up: NICMOS Science Previous: HST NICMOS Observations of . ... Observations of P . ... The NICMOS team has devised a comprehensive program of observations of the Galactic Center. ... Data in hand give a first look at variability and a detailed look at the search for the tip of the main sequence will be discussed where NICMOS has demonstrated adequate sensitivity and photometric precision to identify likely O8-B1 stars at the Galactic Center. ...

... Now primarily for Apogee cameras, XmCCD was developed initially for SBIG cameras and legacy support for them is still included in this version. SBIG ==== SBIG has provided the library used here. It is the latest one they offer and the files included allow support for Android and Mac OS X. This distribution of XmCCD includes source code to utilize the SBIG shared library libsbigudrv.so with a Motif-based graphical user interface. ... The open source code for this library is included here. ...

... P2491 Date Received: 2009-Mar-09 11:01:45 Technical Page Proposal Type: General Category : Observation Category : Total Time Requested: Minimum Useful Time: Prop osal Title: ABSTRACT: Regular Pulsars Galactic 40 Hours 20 A 770-MHz Arecibo pulsar survey of globular clusters The scientific applications of pulsars in globular clusters are plentiful and include the first ever proof of the existence of ionized gas in ...

The radial distribution of metallicity of star-forming galaxies in a galaxy cluster can inform us about the mass assembly and enrichment history of the galaxy cluster. ... Both galaxy clusters are cool-core clusters at redshift z т?? ... The gas-phase metallicity of star- forming galaxies in MACS1115+01 exhibit anti-correlation with projected distance т??0.15 ТБ 0.08 dex/Mpc, whereas the radial metallicity distribution of RXJ1532+30 is statistically flat (т??0.09 ТБ 0.12 dex/Mpc). ...

... ALMA . ... ARC Staff at ESO . ... The European ALMA Regional Centre (ARC) provides the interface between the ALMA project and the European science community. ... Below you can read the latest Announcements from the European ARC Network.. ... The call for 1-mm Very Long Baseline Interferometry (VLBI) proposals to use phased ALMA at Band 6 in Cycle 4, in collaboration with the Event Horizon Telescope Consortium (EHTC), will be released to coincide with the ALMA Cycle 4 Call for Proposals in March 2016...

... Cataclysmic Variables . ... The main aim of this survey is to discover new stellar binary systems with orbital periods less than ~80 min. ... The intensity of stellar objects can vary on a wide range of time-scales, ranging from seconds to months to years. ... Most of these surveys are sensitive to timescales longer than a day. ... For instance, the 0.3 deg x 0.3 deg survey using the Canada France Hawaii Telescope was sensitive to variations on timescales as short as ~8 min (Lott et al 2002) . ...

Magnetic Fields around Radio Galaxies Robert Laing (ESO) Laing et al. ... 2008) Negligible depolarization and 2 rotation Almost all Faraday effects must be due to foreground material How to fit depolarization caused by foreground Faraday rotation Complex polarization Rotation measure Integrate over a beam Observed RM for 0 2 rotation and depolarization Faraday rotation and depolarization 5.5 arcsec FWHM Faraday effects at high resolution FWHM = 1.5 ...

Simulating the Evolution of Stellar Clusters ? ... Resonant Exchange (few Myr) 4perturbed: 6000d, e=0.94 4CE + CE - DWD (0.35d) 2.0 MS 0.8 WD 4GR - merger after 10 Gyr M = 1.6 Msun Comparison with Data: Simulation of M67 H 12,000 single stars (KTG1993 IMF: 0.1 - 50 Msun ) H 12,000 binaries (q: uniform, e: thermal, a: flat-log, max 50 au) H Z = 0.02 H Circular orbit at Rgc = 8 kpc H Plummer Sphere in virial equilibrium 4M ~ 18700 Msun 4 Rt = 32 pc 4Trh ~ 200 Myr 4s ~ 3 km/s 4nc ~ 200 ...

Stellar Clusters are very useful laboratories for empirically studying stellar evolution. ... All cluster stars are at the same distance . All cluster stars have the same physical age . ... CM diagram Young Cluster In this case we see the Main Sequence fully represented. The blue dots represent massive stars with short main sequence lifetimes. ... Thus, identifying the most massive star which is still on the main sequence is an effective means of determining the age of a stellar cluster. ...

Following are instructions to build and install the programs in this distribution. Make sure that you have all necessary tools for building executables. ... The automatic build process expects a configuration file called Config.local . ... The configuration file specifies the directory in which to install the binaries, as well as control over the generation of debugging code and reference clock support. ... Cleans out object files, programs and temporary files. make distclean . ...

... Fitting the observed dependence includes calculations of the polarization cross-sections averaged over particles orientation and size distribution, their normalization and the comparison of obtained dependencies with Serkowski's curve representing observational data for a chosen star. ... Variations of the polarization factors with wavelength are shown in Fig. 16 for homogeneous spheroidal particles with PF orientation. ... The distinction between prolate and oblate spheroids is also clearly seen. ...

. N OTE: . Only clusters with R<60 kpc were used to compute the spatial parameters and metallicity gradients for all subsystems except the corona. The numbers in parantheses give the number of clusters for which the corresponding parameter is known. The X O scale length of the old halo is strongly distorted by the observed asymmetry of the distribution of the corresponding clusters projected onto the XY plane ( Fig. 4А ) . discussion in the text | previous table .

... Globular cluster NGC 2808, elliptical galaxy NGC 2986, and the Sextans Dwarf . ... Globular clusters rotate at heart . ... Originally, we observed these globular clusters to measure their central velocity dispersions that is, the random motions of stars within a cluster. ... Future observations of the remaining 16 clusters the team plans to study will shed light on this and other questions, such as a possible correlation between rotation and the position of a globular cluster inside our galaxy. ...

... 145Slee,Roy Savage We present detailed radio and optical parameters for the stronger radio sources in 58 Abell cluster fields observed with the Very Large Array (VLA) using scaled arrays at 1.5 and 4.9 GHz. ... The cluster fields were distributed over 24 h of RA and between declinations +35 deg and -30 deg. ... Optical identifications Cluster Source Radio Centroid Optical Position EF Ang. ...

Title: A New Model of the Gravitational Lens 0957+561 and a Limit on the Hubble Constant . Authors: Norman A. Grogin , Ramesh Narayan (Harvard Univ.) ... Title: ROSAT/PSPC observation of the distant cluster CL0939+472 . ... Title: Interaction in the Bimodal Galaxy Cluster A3528 . ... Title: Cosmological Implications of Galaxy Cluster Evolution . ... Title: Galaxy Cluster Virial Masses and Omega . ... Matches 201 to 222 from a total of 222 matches for the search pattern galaxy cluster . ...

... We demonstrate through numerical simulations that model parameters estimated with our technique are essentially bias-free, even when the average number of counts per bin is 1. ... The IW technique avoids such biases by estimating through successive iterations, where for each iteration, j, , and the best-fit parameters are determined by minimization of . ... In our sample, we find that the minimum values and best-fit parameters converge after about 6 iterations. ...