... 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...

... 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: Reduction procedure Up: Extinction and transformation Previous: Strategy . Standard stars can be included in the extinction solution, if one is careful. The problem is that there are usually appreciable ``conformity errors'' due to mismatch between the instrumental and the standard passbands [ 16 ]. ... Thus, it is wrong to assume that the transformation between the instrumental system and the standard system is exact, even if there were no measurement error in either system [ 1 ]. ...

... 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...

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: . ...

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. ...

... 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 . ...

... This routine is designed to read in the current correlator set-up, go to the chosen source, and then take data pointing directly at the specified source. This routine will automatically wait until you are on source before beginning to take data. ... Additionally, this routine allows you to take an ON/OFF calibration pair (one 10s scan with the noise diode on, followed by a 10s scan with the diode off), using the chosen noise diode configuration (see Section 1.6 . ...

... The J, H and K bands are characterized by a bright background, such a background is mainly due to the emission of atmospheric lines and of thermal radiation. ... If the source cover a large fraction of the slit, spectra off-source must be observed to adequately sample the sky background. ... The on chip integration time (time spent in each position of the slit) must not exceed 40 seconds in J and H bands and 60 seconds in K band. ... We suggest a sequence of 10 for each elementary integration time. ...

... Using the self-consistent 3D hydrodynamical code in Kobayashi et al. (2007) , we simulate the star formation and chemical enrichment history of the Universe. ... We also predict the rates of supernovae and gamma-ray bursts, and the properties of the host galaxies, which will be observed with the ANU's new SkyMapper telescope. ... Supernova feedback on galaxy formation. ... Feedback from active-galactic nuclei (AGN). ... COALA : Universe Galaxy AGN Star Planet ...

... Optical photometric data were taken of fields encompassing all these sources during a total of seven telescope runs. ... The initial goal of the photometric observations is to follow up the X--ray sources, assign them colors in a standard system, so that the observed objects can be placed on a color--magnitude diagram. This can be used to verify that the X--ray sources are indeed PMS stars. ... Aperture photometry was performed using the APPHOT package in IRAF. ...

... 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. ...

... 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. ...

... New IRAF tools for the photometric calibration of optical/IR images are presented. The new tools are standard star catalog and world coordinate driven, requiring both accurate standard star catalog coordinate and accurate image coordinate data. Network access to standard star catalog servers is supported. ... The photometric calibration software will automatically convert the standard star coordinates from the standard star coordinate system to the image coordinate system. ...

... Astrophysics Group . ... Optical Interferometry . OIFITS: A Data Exchange Standard for Optical (Visible/IR) Interferometry . ... OIFITS is a standard for exchanging calibrated, time-averaged data from astronomical optical interferometers , based on the FITS Standard (OIFITS is a registered FITS convention ). ... The OIFITS standard is used in the biennial optical interferometry Imaging Beauty Contests: . ... A data exchange standard for optical (visible/IR) interferometry. ...

Notes concerning the observations made by UKIRT for the YY Gem programme in March 1988. ... As spot modulation effects are relatively more prominent in V and flare effects in B, it was decided to monitor in K and V during eclipses and in K and B at out of eclipse phases. ... The data were corrected for extinction using the following extinction coefficients: B 0.27, V 0.10, K 0.07, J 0.10 . ... The following colour equations were derived for the UKIRT optical data using VISPHOT. ...

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. ...

... 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. ...

Next: NICMOS/HST H-band (F160W) Images Up: NICMOS Science Previous: HST NICMOS Observations of . ... Observations of P . ... The NICMOS team has devised a comprehensive program of observations of the Galactic Center. ... Data in hand give a first look at variability and a detailed look at the search for the tip of the main sequence will be discussed where NICMOS has demonstrated adequate sensitivity and photometric precision to identify likely O8-B1 stars at the Galactic Center. ...

... 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 . ...