... A set of formulae has been developed to correct aperture photometry for CTE loss with dependencies on the X and Y positions, the background counts, the brightness of the star, and the time of the observation. The observations indicate that for very faint stars on a very faint background, the CTE loss from the top to the bottom of a chip has increased from about 3% shortly after the cool-down of WFPC2 (April 23, 1994) to roughly 40% in February 1999. ... Figure 5: Same as Figure 4 for X-CTE. ...

... 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 a simple 2-D Gaussian Point Spread Function (PSF) on a constant (flat) sky background, I derive a theoretical photometric and astrometric performance model for analytical and digital PSF-fitting stellar photometry. ... The photometric performance is maximized when either the effective background area or the effective-background-level measurement error is minimized. ... An important, but frequently ignored, noise source is the uncertainty of the measurement of the effective background level ( )...

... Applications . ... The B/W Chilled CCD Camera model C5985 is a highly sensitive CCD camera developed for observation under a wide variety of circumstances. In any application, from very bright stop action situations to extremely low light fluorescence conditions this camera will produce excellent images. ... When using with ARGUS-20 Image Processor, B/W Chilled CCD camera driver C6391 is required. ... Built-in image memories . ... Built-in computer interfaces (SCSI) and RS-232C . ...

... Meta Index / Home Page / Description / Soft flare rejection for . The EPIC-pn fast timing mode was designed so that a time resolution of 0.029 milliseconds can be achieved. ... Below this energy the data is affected by so-called soft flares which are caused by stack overflows generated by high energy particles. These so-called soft flares have sharp rise (from 0 counts/sec to several thousand counts/sec in 0.10-0.15 sec) then decaying back 0 counts/sec slightly slower in about 0.3-0.4 sec). ...

In this gallery are many images of Low Surface Brightness Galaxies which have recently been discovered and analyzed. ... The central surface brightness of this galaxy is 24.28 . Malin 2 This galaxy is another huge disk galaxy with a scale length of 15 kpc and a redshift of 15000 km/a. The high surface brightness knot in one of its spiral arms actually has the same color, luminosity and H-alpha equivalent width as the entire Large Magellanic Cloud . ... Truly it is a Low Surface Brightness Galaxy. ...

New RRC variables with an additional non-radial pulsation . PZ, vol. ... We present a new study of 14 known RR Lyrae variable stars from the Catalina surveys periodic variable star catalog. ... New Double-Mode RR Lyrae Variables III . ... We present a new study of 123 known RR Lyrae variable stars from the Catalina surveys periodic variable star catalog. ... According to these data, the stars are double-mode RR Lyrae variables, pulsating in the first-overtone and fundamental modes. ...

... Copyrightї1997 Bob Yen (byen@ix.netcom.com) (http://www.comet-track.com/hb/hb.html) . ... Information on Comet Hale-Bopp for the Non-Astronomer Hale-Bopp rotates about twice a day (3/14/97) . ... The Comet Observation Home Page was been selected to receive the Griffith Observatory Star Award for the week of February 2 - 8, 1997 for excellence in promoting astronomy to the public through the World Wide Web. ... Typically, about 1,000 individual users/computers access this page every day. ...

... Flux density at 1 GHz (/Jy): 19 . ... Notes: This is the remnant of the SN of AD 1006. ... Optical: Filaments to the NW, with broad H component. ... Point sources: The background Schweizer Middleditch star is near the middle of the remnant. ... van den Bergh 1976, ApJ, 208, L17. Optical observations. ADS . ... X-ray spectroscopy. ... Schweizer & Middleditch 1980, ApJ, 241, 1039. ... Optical spectroscopy of the Schweizer Middleditch star. ... Optical spectroscopy. ... 2013, A&A, 552, A9. ...

adapted from Observe: Eclipses, published in 1979 by the Astronomical League and "Safe Solar Filters," by B. Ralph Chou, Sky and Telescope, August 1981) . ... Tape TWO pieces of film together into a sandwich, and tape this over the opening in the cardboard. ... The cardboard frame will act as a shade from the bright Sun, while you safely observe through the film sandwich. ... Undeveloped film is not safe. ... tape . ... At the end of one of the tubes, tape the aluminum foil, and make a tiny pinhole. ...

Aitoff Projection showing ChaMP Fields . ... Main survey: >20 from galactic plane. ... Galactic Plane Survey: No subarray fields: reduced area and more complicated processing . ... Short exposures included except NGC galaxies . Galactic Plane Survey: > 30 ksecs . ... Galactic Plane Survey: >10% contamination by a diffuse/distributed X-ray or optical source. ... E(B-V)= (B-V) - (B-V) 0 which translates to visual extinction A V via . ... Crudely, E(B-V) can be related to Galactic latitude via . ...

... CentralProcessor 0.11 documentation . BETA Processing Pipelines . ASKAPsoft is the suite of processing software developed by the ASKAP computing team to handle the pipeline processing of ASKAP observations. ... BETA processing uses a slightly different approach, particularly in the calibration method, and the set of scripts detailed here are designed to demonstrate a BETA reduction approach with ASKAPsoft. ... ASKAPsoft processing of BETA data . ... How to run the BETA pipelines . ...

... There are preliminary series of photometric and radio spectral observations of the above-mentioned stars, archival data on the light curves of the stars, results of the search for OH and H 2 O maser emission in IRAS point sources that possess the IR parameters similar to Miras. ... The aim is a detailed study of the maser emission variability. ... In 1996-1997, astronomical observations of Mira Ceti-type stars (miras) were carried out in three spectral ranges: optical, infrared, and radio. ...

To main of Laboratory . The research work and design of optical and optical-electronic devices are carries out by laboratory staff: . ... Lens: . ... In the layout 1 prism systems perform functions of dispersive element, corrector of aberrations, optical reducer. ... Spectral range 200 - 400 nm; . ... Back Forward . ... The main corrector's function are compensation of field aberrations of the main spherical mirror of a telescope (diameter of 600 mm, f'=1200 mm) and increase aperture ratio. ...

Next: Gravitational Wave Background from Previous: Galactic Gravitational Wave Background . ... It is intuitively clear that at frequencies above the critical ones for our Galaxy, one will detect rare bright jerks produced by coalescing white dwarfs   (at a rate of 1 per 100 year) and NS (at a rate of 1 per - year) in our Galaxy, against a background of the extragalactic stochastic GW. ... Firstly we consider GWB from close individual galaxies, and then will discuss overall extragalactic GWB. ...

Proposal Identification No.: A2505 Date Received: 2009-Mar-17 15:15:28 Technical Page Proposal Type: General Category: Sub-Category: Observation Category: Total Time Requested: Minimum Useful Time: Prop osal Title: ABSTRACT: Short Astronomy Spectroscopy Extragalactic 3 Hours 3 hrs Testing a new model of OH megamaser emission A new radiative pumping model has recently been developed that predicts the expected OH megamaser strength in merging, IR-bright galaxies. ...

. 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

Next: BASIC PROPERTIES Up: R CORONAE BOREALIS STARS Previous: INTRODUCTION . RCB stars are named after a star just visible to the naked eye in the constellation of Corona Borealis. RCrB was discovered by Edward Pigott (1797), an English amateur astronomer, who had been observing a star in the `Northern Crown' for over a decade. ... Since 1795, other RCB stars have been discovered and their properties have been carefully observed. ...

The night sky brightness, together with number of clear nights, seeing, transparency, photometric stability and humidity, are some of the most important parameters that qualify a site for front-line ground--based astronomy. ... Night sky at ESO-Paranal (Chile). ... Night sky brightness data . ... UBVRI night sky brightness at ESO-Paranal during sunspot maximum (A 2003, PDF) . ... The Dancing Sky: six years of night sky observations at Cerro Paranal (Starlight 2007 conference proceedings, PDF) . ...

... In typical nightly use, the wide field and planetary telescope and cameras record images of favorably placed objects in the sky, including constellations, bright variable stars, nebulae through narrow-band filters, comets, the Moon, and planets. ... Shared Skies telescopes are available for use by students at the University of Louisville and the University of Southern Queensland, and by teachers and students in middle and high schools mentored by faculty at the universities. ...