... 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. ...

... An overall criterion for standard-star selection is the accuracy needed in the final results: if you need more accuracy, you will need more standard stars. ... While it is possible to get a rough estimate of the extinction by observing different standard stars at high and low airmasses, the relatively large conformity errors in most photometric systems, together with the low accuracy of some standards, make this method very inefficient (see Young [ 10 ], p.178). ...

... Science . ... Science Users Information > Observing with ESO Telescopes > Observing Tools and Services > Standard Stars Catalogues > Standard Star Catalogue Search Tool . ... Publications with ESO Data . ... ESO Data . ... This tool searches the standard star catalogues for standards that are within dX airmasses of the target at a given LST. ... In this case put the LST when the target was observed in the TargetLST box as before, and put the LST of the standard star observation in the StdObs LST box...

... ATNF Home . About ATNF . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Astrophysics graduate student programs . ... Australian Square Kilometre Array Pathfinder . Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . Mopra radio telescope . ... Visiting Parkes radio telescope . Visiting Australia Telescope Compact Array . ... Parkes radio telescope webcam . ...

... The absolute flux calibration of NICMOS will be calculated from observations of standard stars with known flux distributions F( ). ... In order to expand the set of IR standard stars in the appropriate flux range for NICMOS, M. Rieke, R. Thompson, and collaborators at the University of Arizona are making photometric observations of solar-analog stars, which will be used to normalize the solar spectrum to the observed IR magnitudes. ... Relative flux references accurate to 1.5% for standard...

HI spectral-line observations of galaxies (Karen O'Neil) . Measuring the width, flux, etc. of the HI profile of two galaxies, using some combination of : dwarf emission line, HVC emission line, spiral emission line, and spiral absorption line. This project was designed to demonstrate the fundamentals of spectral line observing and position switching. ... The types of galaxies observed in this project are being kept open and will be determined when the project LST is known. ...

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: . ...

... 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. ...

OSSERVATORIO ASTROFISICO DI ARCETRI CENTRO PER L'ASTRONOMIA INFRAROSSA E LO STUDIO DEL MEZZO INTERSTELLARE LARGO ENRICO FERMI, 5 -- I­50125 FIRENZE Firenze, September 30, 1994 FROM: C. Baffa TO: Tirgo Staff SUBJECT: Data handling with Tirgo Nicmos3 instruments All data taken with Tirgo Nicmos3 instruments (Arnica and Longsp) are stored directly as standard FITS files at 16 bits integer format. ... The acquisition program never rewrites over an old file. ... An example in table 1. ...

... News Latest News News Archive Newsletter Quarterly Status Report . ... Calibration strategy, status and factors limiting success: Chandra . ... Calibration strategy, status and factors limiting success: XMM-Newton . ... Calibration strategy, status and factors limiting success: Swift . ... Calibration strategy, status and factors limiting success: RXTE . ... Calibration strategy, status and factors limiting success: Suzaku . ... Calibration strategy, status and factors limiting success: Integral . ...

... Superb optical performance coupled with time proven computerized pointing and tracking has made the LX200 ACF series a best-seller in the high-performance telescope class. ... MeadeтАЩs new LX70 Series offers high-quality German equatorially mounted telescopes with slow-motion controls and heavy-duty steel tripods. ... For crisp wide-field observing and imaging, few optical designs match the performance of a true triple-element apochromatic refractor. ... Meade Standard Field Tripod #07020. ...

... A theory suggests that a certain sub-class of gamma-ray bursts all have the same absolute magnitude. ... The author claims that this absolute magnitude is so different from that in the previous sample that this must belong to a new sub-class of gamma-ray bursts. ... To do this, there needs to be some feature in their spectra which correlates with their absolute magnitude. ... Consider a telescope which is continually monitoring a star, looking for transits due to planets orbiting this star. ...

Bridge World Standard Bridge World Standard (BWS) is a system based on the majority preferences of approximately 125 leading experts and thousands of Bridge World readers. ... Jacoby transfers (splinter rebids; game raise is slam try; two diamonds plus two spades forcing only one round); two spades shows minors; three hearts invitational, major two-suiter; Texas transfers; Stayman (two-spade rebid invitational; two-heart rebid weak; minor rebid forcing); Smolen; three of a minor invitational; Gerber. ...

... 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. ...

... 237S (SIMBAD/NED BibCode) ================================================================================ Keywords: Sun: UV radiation - atmospheric effects - Sun: atmosphere - lines: identification Description: An ultraviolet atlas of the solar spectrum with a spectral resolution of 15mA in the region 1948-2000A is presented. ... The wavelength atlas with a list of about 550 lines has been synthesized from data at center of the Sun ({mu}=1) and at {mu}=0.89, smoothed out over an area of 30 arcsec. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Space Flight . ... Earth Satellites . ... Leonid meteors seen from 13 km altitude aboard an aircraft during the 1999 Leonids Multi-Instrument Aircraft Campaign (Leonid-MAC). Comet Tempel-Tuttle provides the cometary debris for the Leonid meteor shower. ... Every 17-19 November Earth crosses Tempel-TuttleтАЩs orbit and the Leonids become visible. With clear, dark skies observers may see 10 to 15 Leonid meteors every hour on those mornings. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... 71 ; The solid line is the measured solar spectrum considering ISODY+ passband and a 1% of stray light contribution. ... Advanced Astronomy for Heliophysics Plus (ADAHELI+) is a project concept for a small solar and space weather mission with a budget compatible with an European Space Agency (ESA) S-class mission, including launch, and a fast development cycle. ...

... The New 1997 IEEE Standards Products Catalog features the complete listing of standards publica-tions and services IEEE Standards offers, along with the information you need to place your order. ... Books and Other Products on Standards - contains a detailed listing of informative print and electronic publications relevant to standards and their implementation in areas of electrical engineering, electronics and computer technology. ... IEEE Standards Products Listing 22 . ... Power Electronics 41 . ...

. To redirect the standard output from a command use the > (greater than) symbol followed by the name of the output file. If the file that you redirect standard output to does not already exist it will be created. For example: grep Smith /etc/passwd > popular . This redirects the standard output from the grep command so that it goes to the file popular . This file will contain all occurrences of the string Smith that were found in the /etc/passwd file. **Caution** . Did You Know? .

... Книга Николая Гавриловича Курганова (1725-1796) - талантливого самородка, солдатского сына, пробившегося благодаря своим способностям и трудолюбию в науку и в двадцать лет получивший звание "ученого подмастерья", а тридцать девять - профессора математики и навигации. ПИСЬМОВНИК стал настольной книгой многих поколений русских людей на протяжении четырех царствований - от Екатерины до Николая Первого. ...