... Mindful of these biases, I can now explore the relations between the measured rotation periods and various other observables. The hypothesis behind monitoring stellar variability is that active stars have asymmetric spot distributions on their photospheres. ... They found that only stars with rotation periods greater than seven days show variations greater than 0.4 magnitudes at I. Bouvier et al . ... 1993a) demonstrated a relation between X--ray flux and spectral type in ZAMS stars. ...

A comparative study of type I and type II supernovae . ... Sternberg State Astronomical Institute, Moscow, U.S.S.R. (Received 26 November, 1985) . ... No significant difference between SNe I and SNe II has been found in their radial distribution and frequency of outbursts in spiral galaxies. ... The radial distribution of type Ia SNe in spiral galaxies is only slightly steeper than the one for SNe II, while SNe Ib/c are more concentrated towards the central regions. ...

We compare atomic gas, molecular gas, and the recent star formation rate (SFR) inferred from HЮБ in the Small Magellanic Cloud (SMC). ... This allows us to disentangle conversion factor effects from the impact of metallicity on the formation and star formation efficiency of molecular gas. ... At a fixed total gas surface density the SMC has a 5-10 times lower molecular gas fraction (and star formation rate) than large spiral galaxies. ...

... The distribution of galactic RCB stars is controversial. Several authors have argued that they belong to a thick galactic disk, and are thus old Population I stars. However, they may alternatively belong to the even older galactic bulge (Population II). ... In either case, the populations are sufficiently old that RCB stars must have relatively low masses ( ). ... These are the only RCB stars for which a distance is known and hence for which an absolute magnitude can be deduced. ...

International Service of Geomagnetic Indices (ISGI) of the IAGA . ... World Data Center C1 for Geomagnetism (WDC-C1), . Solar-Terrestrial Physics Division in Copenhagen, Denmark . ... Sodankyl Geophysical Observatory Geomagnetic and Ionospheric Data . Space Physics Text Book (Oulu): Magnetic activity indices . ... Solar Data Analysis Center (SDAC) . ... Mauna Loa Solar Observatory Analysis Center of HAO/NCAR in Boulder, Colorado . ... Neutron Monitor Server , University of Chicago . ...

... RelatedљPages . ... FITS-WCS and related software . Several implementations of the FITS WCS standards are available: . The WCSLIB software distribution (i.e. this library) may be obtained from http://www.atnf.csiro.au/people/Mark.Calabretta/WCS/ . ... The Kapteyn Package http://www.astro.rug.nl/software/kapteyn/ by Hans Terlouw and Martin Vogelaar. pywcs , http://stsdas.stsci.edu/astrolib/pywcs/ by Michael Droettboom. ... Gentoo, http://packages.gentoo.org/package/sci-astronomy/wcslib . ...

... A universal physical relation for quasars . ... Harvey Tananbaum and his collaborators have first observed a relation between the soft X-ray and the optical/ultraviolet emission in AGN in 1979. Such relation is nonlinear, and it is usually parameterized as dependence between the logarithm of the monochromatic luminosities at 2500 †Е ( L 2500†Е ) and 2 keV ( L 2keV ) . ... Yet, the dispersion along the L 2500†Е тАУ L 2keV relationship is found to be rather high, typically ~0.35тАУ0.4 in log units. ...

Next: Estimating the angle Up: Wavelength Calibration Previous: General Description . The wavelength calibration involves a physical equation, the echelle relation and regression analysis to achieve estimates of the dispersion relation. Provided that the echelle dispersion is performed with a grating, any echelle spectrum can be calibrated usually with four lines used as pre-identifications and a catalog of laboratory wavelengths associated to the calibration lamp. ... Echelle Relation) . ...

Do LIRGs follow the Tully-Fisher relation? ... For a small we can say majority of investigate i Conclusion number of galaxies in our sample, that the T-F relation holds. ... The purpose of this research was to study the LIRGs (Luminous Infrared Galaxies) and see if they follow the Tully-Fisher relation. The LIRGs are different to normal galaxies in the fact that they emit 90% of their light in infrared. ... The faster the galaxy rotates, the wider is the emission line in velocity. ...

... The concepts of Fourier frequency and wavelet duration are obviously related. ... Among many sensible definitions, we chose to require that the peak of the wavelet mean spectrum should be matched with the singularity of the Fourier transform of the cosine wave. Then, it can be shown that the frequency of the cosine is related to the wavelet duration by the relation . ... The ambiguous definition of the duration of an event is common to the sizing of any object of irregular shape. ...

... 2.3 Establishing the Extragalactic Distance Scale . ... 2.3.2 The Second Rung: Distances to stellar clusters . ... 2.3.4 Distances to Local Group Galaxies . ... The Luminosity Function of Planetary Nebulae . ... 3.2.2 Clusters of Galaxies . ... 4.2 Evidence for Dark Matter as a Function of Scale Size . ... 4.3 Other Dark Matter Indicators for Galaxies . ... What is the nature of the large-scale distribution of matter in the universe as traced by the three-dimensional galaxy distribution? ...

... Recent Topics . ... MAO main . ... The third-order space-by-time relation . ... Тема: The third-order space-by-time relation . ... The mass m experiences a gravity force toward the sun and . ... will experience the Coriolis force or Coriolis acceleration. ... differentiated space-by-time twice and discovered equation2. ... If one differentiates . ... time differentiation of space-by-time. ... third-order space-by-time relation. ... understand the third-order space-by-time relation. ... MAO NASU . ...

... The task also issues a number of housekeeping related messages and values and also writes several keywords to the EXPOSURE extension (the information is usually CCD-dependent and it is thus important that it is kept and propagated through the event file processing chain). ... Filter: the filter wheel position is derived from the position sensor potentiometer (housekeeping column F1122 contained in the main periodic housekeeping file PNPMH1 , HK mnemonic H_CE_FWSPOT). ...

... We have studied scaling relations (virial mass versus CO luminosity, luminosity versus size, linewidth versus size) for molecular clouds in the 30 Dor and N 159 regions in the Large Magellanic Cloud. ... The study of molecular clouds in the Galaxy has resulted in a number of scaling relations between global cloud properties such as mass, density, luminosity, size and velocity dispersion (e.g. Larson (1981) , Scoville & Sanders (1987) , Solomon et al. ... Elmegreen B.G., 1989, ApJ , 338 , 178. ...

... Pre-university education . ... SSAU History . ... International relations . ... Thus, in different years the University entered into agreements with the universities of China (Harbin Politechnical Institute, Beijing Aerospace University , Beijing Politechnical University , North-West Politechnical University , Bradley University (USA), Sofia Technical University (Bulgaria), Stuttgart Technical University (Germany), Berlin Technical University (Germany), Carlow Technical ...

Links on this page are to sites that hold information on the Sun , our nearest star . ... Big Bear Solar Observatory (BBSO) , California, USA. Mauna Loa Solar Observatory (MLSO) , Hawai'i, USA. ... Space Environment Center, Current Solar Images , Boulder, Colorado, USA. ... Solar Data Analysis Center, Latest Images , at GSFC, Maryland. ... NSSDC - National Space Science Data Center, Solar Physics (at GSFC). ... NSSDC - National Space Science Data Center, Space Physics (at GSFC). Back to Links ...

The ESA/ESO Astronomy Exercise Series 2 . The Distance to Messier 100 as Determined by Cepheid Variable Stars . ... The small variations in distance to the individual Cepheid variable stars in the Cloud are negligible compared with the much larger distance to the SMC. ... In this way Cepheid variable stars can be used as one of the 'standard candles' in the Universe that act either as distance indicators themselves or can be used to calibrate (or set the zero point for) other distance indicators. ...

... Scaling relations of galaxies: . ... 2007) . ... This research is now being extended to other clusters such as Hydra and Centaurus, by Ingo Misgeld . ... 2007 , Misgeld et al. 2008 and 2009 ) support a picture where the scaling relations of dwarf galaxies are shaped more by internal than external agents, given that colour-magnitude and magnitude-surface brightness relations agree quite well between the low-density Local Group environment and dense clusters like Fornax and Hydra. Misgeld et al. ...

... 4. (a) Distribution of distance from the Galactic plane, (b) kinematic diagram, and (c) relation between metallicity and distance from the Galactic plane for RR Lyrae stars with [Fe /H ] > -0.95 . ... The solid line in the middle panel is a regression line, whose slope is determined by the subsystem’s rotation rate; the open circles and dashed line correspond to stars with [Fe/H] > -0.4, and the filled circles and dashed line to stars with -0.95 < [Fe/H] < -0.4. ... next figure | privious figure . ...

Next: A Gravitational Wave Map Previous: Critical Frequencies and Gravitational . In this section we consider the GWB spectrum as such, that is, we study how dimensionless strain metric amplitude h is dependent on frequency. For a sample of N independent binaries emitting GW at a given frequency the net result is . ... are, respectively, effective distance to the sample and effective mass of the binaries (in solar units) producing the GW radiation at the frequency . ...