... Stellar Evolution is driven entirely by the never ending battle between Pressure and Gravity . As imbalances are reached, the star is driven to find a new Energy source. ... Pressure and gravitational forces are equal, the star is stable and its core is sufficiently hot to fuse Hydrogen into Helium More about main sequence stars . ... The luminosity generated by the core fusion of Helium into Carbon is far greater than the shell luminosity associated with the fusion of Hydrogen into Helium. ...

Next: Examples of Setup Files Up: Setup Files Previous: Setup Files Contents . Over 200 standard setup files have been created, covering many of the normal modes of observing. ... These especially include precisely defined, and somewhat complex cases like the Mark III standard modes (although MarkIII went the way of the dinosaur long ago. ... v '' files: . These are setup files for VLBI observations using VLBA recording formats. ... These are setup files for Mark III observations. ...

... NGC 6357s Cathedral to Massive Stars . ... Credit Copyright: NASA , ESA and J. M. Apellюniz ( IAA , Spain) Explanation: How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun, nearly making it the record holder. ... Publications with keywords: massive stars . Publications with words: massive stars . ... A Massive Star in NGC 6357 . ... Massive Stars Of 30 Doradus . ...

... 2006 December 19 . Massive Stars in Open Cluster Pismis 24 . Credit: NASA , ESA and J. M. ApellАniz ( IAA , Spain). Explanation: How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun, making it a record holder. ... Component stars would still remain near 100 solar masses, making them among the more massive stars currently on record. ... About APOD | ...

XG SONG SHOWCASE FILES ********************************** These songs are short excerpts from the increasing XG song library. They are here included as Standard MIDI File format data (for playback through a sequencer with an XG-compatible tone module), and as audio data, for playback through a normal CD audio player. ... You will find similar names on the files such as CL30XG,CL30XGA,B,C. For example, CL30XG is the song called "Danse Macabre", and A.B.C represent a certain part of the song. ...

... The bandpass in which the measurement is made must be identified. The bandpass name is recorded in a column labelled BAND. This name, combined with the information in the instrument file, is used to identify the detector in multichannel instruments.) Standard passband names should be used: 'V', 'B', 'U', 'URL', 'R', 'I', 'u', 'v', 'b', 'y', 'betaW', etc. ... Such information must be decoded to a standard band name in the observation-table file. ...

... AST . ... This is arecibo's local time zone (all year since puerto rico does not switch for daylight savings). group , record . ... Each record contains a header followed by data. ... A 5 minute scan using 4 correlator boards at different frequencies is written to disc using 1 second integrations. ... Each group contains 4 records (one for each correlator board). Each record will have a header followed by the data for that correlator board. ... a set of integrations (records) contiguous in time. ...

Last updated 5 November 2003 by JMD . Last link checked 9 October 2003 by JCB . Data from 191 observations of stars with the ARCES were analyzed to calculate exposure times to reach particular signal-to-noise values for bright standard stars. ... An exponential fit to the data shows pretty good agreement and allows for forecasting to fainter stars beyond the limit of the data set ( V ~ 12). The fit was used to calculate the exposure times in the table below: . ...

... DEVELOPER** -- Don Chance **MODIFICATION HISTORY** -- o Initial implementation 9/21/00 o Changed calendar lead time to 2 weeks. drc 2/27/01 o Modified for T-11 calendar building. drc 9/10/01 o Correct 'most recent ephem' query for normal ephems only. mdr 2/17/15 o code cleanup. drc 12/7/15 #*********************************************************************** from abstract_ check import abstract_ ...

... We have assumed a constant in time star formation rate and the total number of stars in the Galaxy, , to be such that the total mass of the galaxy is ; assuming the Salpeter mass function   , we get . ... This number agrees with a standard estimation of the galactic star formation rate of order of per year. In each run of calculations, we trace the evolution of binaries with initial parameters randomly distributed according to the chosen initial laws. ...

XMM­Newton CCF Release Note XMM­CCF­REL­208 OM Grisms Calibration: correcting count rate in extracted spectrum A. Talavera June 12, 2006 1 CCF components Name of CCF VALDATE EVALDATE List of Blocks changed XSCS flag OM GRISMCAL 0004 2000­01­01T00:00:00 --- Header keywords NO --- FLUX GRISM1 NO 2 Changes 2.1 UV Grism Flux Calibration SAS task omgrism extracts the spectrum from a grism rotated image. ... Such a corrected ISF (for the UV grism ­ GRISM1) is implemented in the new OM GRISMCAL 0004.CCF. ...

... Bojan Nikolic web pages home . ... The goal here is to make a publication quality image of the sky with the coordinates labelled in the standard Right Accession/Declination units. ... Use the PGTBOX function which knows how to label the coordinate box in time units . ... тАЬINTтАЭ To draw tick marks and label them (тАЬIтАЭ so that the ticks are inverted, i.e., going outside the box) . ... Ensure that the matrix representing the coordinate system of the image is correct when calling PGIMAG . ...

... Archives . ... His foremost knowledge and historic account on statistical models related to errors may benefit astronomers. Although I didn?t study history of astronomy and statistics, I?m very much aware of how astronomy innovated statistical thinking, particularly the area of large sample theory. ... On the history and use of some standard statistical models . ... The particular reason for this paper into the slog is the following sentences: . ... Chandra Blog . ML Theory . ...

Geomagnetic disturbances can be monitored by ground-based magnetic observatories recording the three magnetic field components. The global Kp index is obtained as the mean value of the disturbance levels in the two horizontal field components, observed at 13 selected, subauroral stations . ... Geomagnetic activity is the occurrence of K variations. ... But K still remains a local index, describing disturbances in the vicinity of each observatory. ...

... August was noteworthy by having the least number of hours of bright sunshine for at least 128 years, that is, since sunshine records began at the Observatory in 1880. ... The month was also exceptionally wet, with rainfall totaling 151.4mm (5.96 inches), nearly twice the average figure (around 81 mm) for August and the seventh wettest August at Armagh since rainfall records began at the Observatory in 1838. In order to find a wetter August we have to go back 52 years, to August 1956. ...

... Data Handling and Products > Data Reduction FAQ > The spectrum of my MOS flux standard star is shifted in wavelength by several pixels. Why is that and how can I correct for it? ... Observing with ESO Telescopes . ... The shift of the flux standard spectrum is caused by a combination of bad centering within the slit and possible wavelength calibration issues. To align the spectrum to the tabulated flux, use the parameter --resp_shift in vmmosscience when determining the response curve. ...

This directory contains Calgary Neutron Monitor Data at five minute resolution. Each file is a gzipped tar archive that contains files of uncorrected count rates and barometric pressures at five minute intervals for one year. A file named snm.calg.fmi.YYYY.tgz is an archive that holds five minute data for the year YYYY. ... So a file named cal01030.fmi contains five minute uncorrected data for year 2001 day 30 (which is Jan 30, 2001). ... A text file named note.txt is also usually present. ...

... Ci sono tanti modi di gestire l'audio attraverso la rete. NetStreamer Х uno di quelli che usano la tecnica piЫ semplice, anche se non Х necessariamente la piЫ efficace: una connessione TCP normale dove ogni nodo intrattiene una sessione indipendente. ... Successivamente, gli utenti che vogliono collegarsi al ripetitore per ascoltare ciР che viene trasmesso, utilizzano altri client specifici per la ricezione. ... Il risultato viene passato ai file di dispositivo per l'input dell'audio digitale. ...

... October 6, 09:00 09:40 . Jorge Melnick (ESO) . ... We present a statistical and temporal analysis of the ground meteorological properties recorded at the five selected sites for hosting the European Extremely Large Telescope (EELT). ... Marc Sarazin (ESO) . The organization and development of the E-ELT site testing campaign by ESO are described. ... The E-ELT Site Testing activities in northern Chile and Argentina are reviewed, and pioneering explorative campaigns are illustrated. ...

... The material in "From Stargazers to Starships" meets several important requirements of the national standards. Pages cited below are from National Science Education Standards National Academy Press, Washington 1995. ... For example: the sections on astronomy not only describe calendars and sundials (including their construction), but also the astronomy of the ancient Greeks, including two different ways in which ancient Greeks estimated the distance to the Moon. ...