Next: Cosmological Molecular Clouds Up: HST and the Previous: Cepheids in NGC . ... Recent calibrations of stellar surface brightness derived by modern observational interferometry show that the Cepheid PLC relations turn out to be much less affected by abundance effects than PL ones. Extragalactic Cepheid distances revisited by a calibrated PLC (V, V-Ic) relation indicate some significant systematic shifts affecting current PL determinations achieved by ground-based and HST photometry. ...

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. ...

Definitions of Magnitudes and Surface Brightness 1 The magnitude system 1.1 Apparent magnitude Astronomers are stuck with the antiquated old system of magnitudes and so a clear explanation of what this system is and how it relates to more sensible units is important. ... 1.2 Absolute magnitude Absolute magnitude is a logarithmic luminosity scale. ... One usually goes by the round about process of referring to the absolute magnitude of the sun. ... Magnitudes and surface brightness 6/6 ...

. Please standby and you will be automatically connected to the new location of the unframed Supernova page. Or, click on the link above. If you have questions or problems, please email me at David Bishop dbishop@vhdl.org . Last modified: Mon Aug 27 12:40:15 EDT 2001

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... Date . ... Authors . ... 1.000 . ... Kniazev, Alexei Y.; Grebel, Eva K.; Pustilnik, Simon A.; Pramskij, Alexander G.; Kniazeva, Tamara F.; Prada, Francisco; Harbeck, Daniel . Low Surface Brightness Galaxies in the Sloan Digital Sky Survey. ... 08/2001 . ... V. The fifth list of 161 galaxies . ... IV (Kniazev+, 2001) . ... Email results to: . ... Return:  Results  Form for manual query . ... Databases queried: Astronomy/Planetary Authors: KNIAZEVA, T Start date: 00/1990 End date: 03/2004 . ...

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. ...

... Outline of the BTF paper by Erwin de Blok (25-2-2002) ----------------------------------------------------- * Description of sample * Data and corrections * Descriptions of method to measure line widths * Description of method to measure inclinations * Corrections to linewidths and magnitudes (inclination, random motion, instrumental resolution, extinction) * Corrections to recession velocities (to Local Group frame, also POTENT etc for nearby galaxies) * Describe B-band ...

... All the information about the propagation of a given plasma wave mode is contained in the appropriate dispersion relation, which relates the angular frequency w to the wave number k (magnitude of the propagation vector k ). ... Phase velocity . ... Group velocity . ... Wave propagation can also be described using diagrams called phase velocity or wave normal surfaces , which give the variations of the magnitude of the phase velocity of plane waves with respect to the magnetic field direction: . ...

... Of course, the scope of chaos is vast, and we do not dare to cover it all. ... He will highly appreciate your help in compiling the list of URLs to such scientific groups and institutions. http://www.cplire.ru/win/InformChaosLab/ - InformChaos Lab (Moscow) . http://chaos.ssu.runnet.ru/ - Laboratory of Nonlinear Dynamics at Saratov State University (Saratov) . ... http://optics.npi.msu.su/sci/chaos.html - Chaos in laser systems . ... http://www.chaotic.com - Randle, Inc. ... Time: 2-6 July, 2001 . ...

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. ...

... Early on, our interest in chirping analysis functions was motivated by a different kind of chirping phenomenon: chirping due to perspective. ... Our interest in radar, however, drew us toward processes that are more accurately analyzed by linear-FM chirplets. ... We have also constructed other chirplet transforms, such as a three-parameter Doppler chirplet representation that models a source producing a sinusoidal wave, while moving along a straight line (e.g. a train whistle). ...

Next: ZGSC (Compressed GSC) and XSKYMAP . ... This is a preliminary report on an investigation of the quality and properties of plates digitized during creation of the Guide Star Catalog (GSC). The results will be vital for reclassifying GSC objects. ... Many objects are measured on more than one plate, and thus have multiple catalog entries. ... Among the shortcomings of the GSC are: biased magnitudes and incorrect classifications for certain objects, presence of artifact objects. ...

... 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 . ...

. XMM-Newton Science Analysis System . imrebin (tools-1.61.1) [xmmsas_20050815_1803-6.5.0] . Meta Index / Home Page / Description . Three options are available: . newvaluestyle =`sum': the values of the corresponding input pixels are simply added. newvaluestyle =`average': the values of the corresponding input pixels are averaged. newvaluestyle =`rms': the output value is calculated as the root mean square of the cooresponding input pixels. XMM-Newton SOC/SSC -- 2005-08-16

... The data for ~ 5500 F-G stars are used to study their kinematics, metal abundance and HR diagram in terms of uvby photometry. The age - metallicity, velocity - metallicity, and age - velocity relations are derived. ... 4) At a given metallicity the kinematics of F dwarfs is close to that of G giants and the kinematics of G dwarfs is close to that of K giants. ... 1) При [Fe/H] < 0 звезды данной металличности обнаруживают отчетливую точку поворота главной последовательности (ГП). ...

... 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. ...

... Bad Astronomy . Misconceptions . ... Bad Astronomy : "That's as remote as the dark side of the Moon!" ... As the tired, hackneyed refrains went on, one in particular caught my ear: " Fly me away to the bright side of the moon, and meet me on the other side." ... As the Moon orbits the Earth, different parts of it get illuminated by the Sun. ... Bad Addendum : At the end of the album "Dark Side of the Moon" by Pink Floyd, there is a voiceover that actually says "There is no dark side of the moon. ...

Workshop on geometric analysis and spectral theory . ... On a class of random walks on groups with infinite number of generators". ... Optimal transportation, weak flows and very degenerate elliptic PDE's". ... Singular solutions to fully nonlinear elliptic equations". ... I will give some hints on how this conjecture is related to minimal surface theory and I will describe some flatness results for non local equations on one hand and on elliptic equations on riemannian manifolds on the other hand. ...