... 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). ...

... 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. ...

... Public . Science . ... Science Users Information > Observing with ESO Telescopes > Observing Tools and Services > Standard Stars Catalogues . ... Observing with ESO Telescopes . ... Publications with ESO Data . ... Large Programmes . ... ESO/GTC Programmes . Public Surveys Programmes . ... Phase 1 Proposals . ... Public Surveys Phase 2 . ... Science Data Products Forum . ... ESO Data . ... ESO Data Access Policy . ... Below follows a non-exhaustive list of on-line standard star catalogues. ...

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. ...

... 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 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 ). ...

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: . ...

... 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. ...

... 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 . ...

... 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. ...

... We have been upgrading the software front-end to WASP (Wideband Autocorrelating SPectrometer, operating from 800 to 4000 MHz) from Lynx-OS to Real-Time Linux and will discuss Real-Time software aspects. We are using a standard parallel ``PIO'' card to receive data from the spectrometer and standard GPIB interfaces that drive a frequency synthesizer for bandpass calibration. WASP and its front-end computer are fully mobile and can be taken to any suitable radio telescope. ...

... 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. ...

... The SMS program is a critical endeavor to investigate whether the predictions of standard cold dark matter cosmology are consistent with the observed matter distribution in the Milky Way halo. It is the deepest, most extended search for optically elusive dwarf satellite galaxies and tidal streams to date, covering the entire Southern hemisphere. ... However only a few dwarf satellites have been found around the Milky Way to date - 22 dwarfs compared to 500-10,000 predicted by theory (Klypin et al. ...

... 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. ...

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. ...

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. ...

... They were determined as a result of orbit improving on the base of all kinds of optical observations available in the catalog of observations of the Minor Planet Center on March 16, 2014 (radar observations have not been used at this stage). ... As the MPC orbits do not all were improved simultaneously with EMP orbits, only 383866 sets of elements were used for data comparison (for selected sets of elements process of improvement had started with the use of the same observations). ...

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. ...

... The following charts/text are intended as tools for monitoring the Type Ia supernovae ( SNe ) event visually or photographically (utilizing telescope equipped CCD equipment).The files include: A replication of The Type Ia SNe , V- magnitude (with data point checks from other cited references)and color index (B-V) templete (to indicate a general color-related trend of the type Ia ... I believe this might help alleviate some of the problems involving the making of acceptable amateur light curves...

... Recent Topics . ... MAO main . ... Fw: ASTRONET: Task 5.4 - observing schools . ... Subject: Re: ASTRONET: Task 5.4 - observing schools . ... with the organization and carrying out observing schools. ... second half of September, and which will be funded by the training and . ... intended for master and starting PhD students. ... actions on observing schools, providing access for students, Master . ... observing schools for master students. ... in form of observing schools for pre-PhD students. ...