Kholtygin A.F., Burlakova T.E., Fabrika S.N., Valyavin G.G., Yushkin M.V. Microvariability of Line Profiles in the Spectra of OB Stars: delta Ori A . ... We have studied variability of the spectral lines of the OB star delta Ori A -the brightest component of the delta Ori triple system. ... However, some of the variable features go outside the band, presumably due to either imhomogeneities in the stellar wind from .Ori Aa1 or non-radial pulsations of the weaker components of the system, Aa 2 or Ab. ...

... SB, Porb = 55.9212d. V0745 Cas| ... Component B of the double system observed brighter than in the Hipparcos Input Catalogue. ... The variability may be due to the fainter component. ... Type ELL: is also possible. pi Cas| ... Variability type and spectral type (F2/F3Ib/II) do not agree. ... Variability type and spectral type (F3/F5II) do not agree. ... Variability may be due to component B. VZ Pic| ... Variability may be due to component B. V1377 Ori| ... SB, Porb = 9.073d. V0421 Cep|105091| ...

As the Universe expands, gravity pulls on the Universe, and slows the expansion down over time. As we look to great distances, we are looking back in time. If we can measure how fast the Universe is expanding in the past, and compare it to how fast it is expanding now, we can see the total gravitational effect of all matter in the Universe. Here we plot the distance between two galaxies as a function of time. ... Universes with lots of material . ...

This is a copy of a Press Release from E.S.O. The most recent ESO observations of bright Comet Hyakutake have shown rapid changes in the innermost coma, within a few hundred kilometres from the cometary nucleus. This result has only become possible because of the unusual combination of a bright comet being near the Earth, together with the excellent imaging quality of the ESO 3.5-metre New Technology Telescope (NTT). ... Go to the ESO Homepage for Comet Hyakutake . ESO/La Silla | ...

The Small Libration of the Satellite in the System of the Asteroid 39 Laetitia . ... Very Long Baseline Interferometry (VLBI), Near Earth Objects (NEOs), near-Earth asteroids (NEAs), small libration of the satellite , Asteroid 39 Laetitia , Crimean astrophysical observatory (CrAO), to automate the observation process, method of frequency analysis , periodicity of changes of asteroid brightness, binary asteroid , binary system , period of axial rotation of components, a satellite ...

Experiment COLD . ... High-Latitude Background Emission . Only the narrow band of the Milky Way near b II = 0 o has been studied at centimeter wavelengths; even here, the most sensitive surveys of the Milky Way have gaps toward the anticenter. ... The right ascension where the band of sky studied comes closest to the Galactic Pole is indicated by the arrow labelled NP. the Milky Way: we detected background emission toward the anticen-ter for the first time, near the radio source W16. ...

... Initial mass function and binary stars . ... The principal goal of this study is to show that the real shape of the initial mass function for low- and intermediate-mass stars differs from the observed one. In particular, comparison of radii of eclipsing binary components and single stars shows a noticeable difference for B0V-G0V components of eclipsing binaries and single stars of the corresponding spectral type. ...

... Gravitational wave search provides insights into galaxy evolution and mergers . ... galaxies . ... Globular cluster NGC 2808, elliptical galaxy NGC 2986, and the Sextans Dwarf . ... Open cluster NGC 2818, spiral galaxy NGC 2964, and spiral galaxy NGC 2976 . ... What are typical star-to-star distances in globular clusters compared to stellar distances in our region of the galaxy? ... RELATED TOPICS: GLOBULAR CLUSTERS . ... Get instant access to subscriber content on Astronomy.com! ...

November 2006 Astronotes 1 Candles in the Dark Image Credit: Wikipedia.org By Colin Johnston, Science Communicator Since the mid-ninteenth century astronomers have used the principle of parallax to measure the distance to other stars. ... How then can we tell, for example, that M31, the galaxy in Andromeda, is 2.2 million light years away? It would be straight-forward to tell how far away a star was if it was exactly the same brightness as our own Sun. ...

Text of these problems is available also in other languages : . ... What can one see in the Moon's sky more often - the Sun or the Earth? ... There are about of 250 millions of stars in the elliptical galaxy M32 (a satellite of Andromeda galaxy). ... The masses of Capella's components. ... You are proposed to estimate the masses of Capella's components, using our observational data. ... A galaxy's mass. ... Estimate the mass of FGC 1908 and compare it to the mass of our galaxy. ...

... Bad Astronomy . ... Bitesize Astronomy . ... Keep Bad Astronomy close to your heart, and help make me filthy rich. ... When Venus is on the far side of the Sun, we see the entire near side lit by the Sun. ... When it is on the near side of the Sun, it shows a beautiful thin crescent, because it is between us and the Sun and we see the mostly unlit dark half. ... To see this for yourself, draw a circle one centimeter across, then, next to it, draw a circle 6 centimeters across. ... 2008 Phil Plait. ...

... Mass . 17a. Measuring Mass . ... A medium-size (1.25 inch wide) binder clip, as is used in offices to hold papers together--the type made of flat blue steel, with two wire handles. ... The theory predicts that the oscillation period should be proportional to the square root of the oscillating mass, including the mass of the clip. Note that gravity plays no part here: the oscillation period would be the same on the Moon or in zero-g. Denoting square root by SQRT, we have . ...

... Subject and Problems of Stellar Astronomy. ... Plane of Galaxy, Methods of Its Location Determination. ... Stars Distances. ... Other Methods of Stars Distances Determination. ... Tangential Velocities, Their Determination by Self-Motions. ... Determination of Solar Apex and Spatial Velocity by Radial and Spatial Velocities of Stars. ... Features of Orientation and Parameters of Peculiar Stellar Velocities Ellipsoid. ... General and Selective Light Absorption in Galaxy. ... Darc Clouds in Galaxy. ...

Polycyclic aromatic hydrocarbons in HII regions: correlation with metallicity . ... We have perfomed the aperture photometry of HII regions using infrared images from telescopes Spitzer and Herschel at passbands 3.6, 4.5, 5.8, 8.0, 24, 70 and 160 m. Emission of PAHs are observed at passbands 3.6 - 8.0 m, 24 m is emission likely of hot small particles and finally large particles are responsible for emission at 70 and 160 m. We determine abundances of PAHs using model of Draine Li (2007) . ...

... This is possible at modest cost due to the low moments of inertia of the telescope and enclosure. ... This same performance will be achieved in higher winds when the telescope enclosure is facing away from the wind, or by using wind screens. ... The telescope system (MILT) will be remotely operable with an on-site operator's assistance by an astronomer located at one of the ARC member institutions. ... Mean Wind Speed . ... Offsets > 10 deg: 1 arc sec rms max . ... 5 sec max, tracking to tracking . ...

... The versatile and efficient INVERTOSCOPE? combines the highest optical performance with unsurpassed mechanical quality, and is backed by LOMO's unique lifetime warranty, the most comprehensive in the industry. ... A 15X focusing eyepiece with two interchangeable reticles (a 10mm/100div scale and a 10mm x 10mm/400sq grid) for convenient measuring and counting. ... A set of stage inserts and extension plates to accommodate a variety of sample vessels such as Petri dishes, flasks, microtest plates, etc...

The Virgin. ... This is a double system with a long orbit and a period of 171 year. The maximum distance between them was 6" in 1925 and it will be 0,5" in 2011. The light of the each component is 3,5 of star value. Near the Virgin star r there is an interesting galaxy M 87 (or the radiogalaxy of the Virgin A) aproximetly the 9th star value. ... The most bright quasar (3C 273) lays in the Virgin, but it is able to see this quasar only in a big telescope. ...

... Take a particularly simple signal: a cosine wave. ... Now, we are going to stretch and shrink the wavelet along the time axis (we assume the data is in the time domain), and at each time compare the shape of the signal to that of the wavelet. ... Figure 3: The wavelet (dotted line) is translated rela tive to the signal (solid line). ... Figure 4: The dashed line plots the `match' between the wavelets (dotted line) and the signal (solid line) as a function of time. ...

Polarization in the 530.3 nm emission line and coronal magnetic field structure O.G. Badalyan1 , V.N. Obridko1 and J. Sykora2 ґ 1 Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, 142092 Troitsk, Moscow Region, Russia 2 Astronomical Institute of the Slovak Academy of Sciences 059 60 Tatranskґ Lomnica, The Slovak Republic a Received: January 15, 2002 Abstract. ... Key words: coronal green line ­ polarization characteristics ­ coronal magnetic field Contrib. ...

The Nuclear Structure of 3C 84 with Space VLBI (RadioAstron) Observations PoS(EVN 2014)021 Gabriele Giovannini1,2 , Monica Orienti2 , Tuomas Savolainen3,4 , Hiroshi Nagai5 , Marcello Giroletti2 , Kazuhiro Hada2,5 , Gabriele Bruni4 , Jeffrey Hodgson4 , Mareki Honma5 , Motoki Kino6 , Yuri Y. Kovalev7 , Thomas Krichbaum4 , Sang-Sung Lee6 , Andrei Lobanov4 , Bong Won Sohn6 , Kirill Sokolovsky7 , Peter Voitsik7 , J. Anton Zensus4 . ... 2014, Tavecchio and Ghisellini 2014). PoS(EVN 2014)021 2. ...