... Surface Brightness of Background Light . Home . ... Data . ... WFPC2 Home . ... Instrument Home . WFPC2 History . ... LRF Data . ... Data Analysis Home . ... Instrument Handbook . Data Handbook . ... Input the surface brightness in magnitudes per square arcsecond. ... Galaxy U-B and B-V colors are drawn from Longo and deVaucouleurs 1983 for representative objects;V-R and R-I are estimated from WFPC2 Handbook Table 6.1. ... AB_xxxxx are AB magnitudes at the standard WFPC2 filter bands. ...

... This paper describes the main algorithms used by the Einstein Level One processing to create the exposure masks and the background maps for Einstein IPC images, and how these algorithms were recreated in the IRAF environment. Our goal was to recreate the algorithms used by the Level One Processing to create exposure masks and background maps for Einstein Image Proportional Counter (IPC) data (cf. sections 2.5 and 2.7 of Harnden et al. ...

. 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. ...

... Figure 1: Data from selected high latitude pointings overlaid in detector co-ordinates. 132ksec total low proton flare conditions, and bright point sources excised . Figure 2: Same data set from selected high latitude pointings but in 0.2-2keV only. ... Figure 3: Same data set from selected high latitude pointings but in 2-10keV only. ... Figure: EPIC MOS data set from selected high latitude pointings plotted as spectra (PATTERNS 12&&#XMMEA_EM), and normalised for approx 1 arcmin square. ...

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) . ...

... X Ray Moon . ... In this digital picture, pixel brightness corresponds to x-ray intensity. Consider the image in three parts: the bright hemisphere of the x-ray moon, the darker half of the moon, and the x-ray sky background. ... Still, the few x-ray photons which seem to come from the moon's dark half are currently thought to be caused by energetic particles in the solar wind bombarding the lunar surface. ... Publications with keywords: Moon - X-ray - cosmic rays - x-ray background . ...

... Usually, H I is seen as bright emission against a darker background, but under the right viewing conditions, it can also be seen as dark absorption against a brighter background. In the case where the background is itself H I emission, the hydrogen is said to be self-absorbed, and the radiative transfer process is termed H I self-absorption (HISA). ... Shown below is a single CGPS H I 21cm spectral line channel at a radial velocity of -41 km/s in the Local Standard of Rest, at l =140њ, b =+1њ. ...

You Can Make Stellar Images Brighter . Articles | ... A few months ago I wrote an article titled "You Can’t Make Them Brighter". So why am I now writing that you can make them brighter. ... The image of a focused star is actually a small disk called the Airy disk, named after the 19 th century scientist Sir George Airy. ... For a given aperture, a smaller Airy disk means that the light is focused to a smaller disk and is therefore brighter. ... www.astronomy.net . About Astronomy Net | ...

... In the three intervening decades there have been many observations of this diffuse emission over a wide range of x-ray energies. ... During the 1970's researchers at the University of Wisconsin, lead by Dr. William Kraushaar, used a series of sounding rocket flights to map the diffuse x-ray emission from the sky in several bands. ... University of Wisconsin Sky Survey map of the B-band (0.13-0.188 keV) x-ray intensity. ... University of Wisconsin Sky Survey map of the 2-6 keV band x-ray intensity. ...

... 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. ...

... We present the ROSAT All-Sky Survey Bright Source Catalogue (RASS-BSC, revision 1RXS) derived from the all-sky survey performed during the first half year of the ROSAT mission in 1990/91. 18,811 sources are catalogued, with a limiting ROSAT PSPC countrate of 0.05 cts/s in the 0.1-2.4 keV energy band. ... Broad band images are available for a subset of the flagged sources. ... Retrieving the full catalogue The ROSAT All-Sky Survey Bright Source Catalogue can be retrieved via your WWW browser: 1. ...

... Imagine that for every pixel in the color image, you take its luminance value (that's how bright it appears). ... In the end, you will have a histogram which counts how many times each luminance value appears in the image (that histogram can be used to analyze the distribution of the luminance values in the image). ... For the watermark effect, we want to use the same value that we used in the Stretch Contrast step, so that the lightest color will be in fact white (255), and nothing will get clamped...

... The Galactic low-mass X-ray binary GS 2023+338 was discovered during the burst on May 22, 1989 with the Japanise satellite Ginga (aka Galaxy). The flux reached 17 crabs (this unit of flux measurement is an bright X-ray source, Crab Nebula) at 10-35 keV. ... No other radio telescope worldwide carried out multi-frequency measurements. ... Upon 14 days the radio flux fell below the detection level at the RATAN-600 in relation to the decrease of the X-ray flux. ...

Measurement of Sky Brightness at the Iranian National Observatory Davoud Afshari1 and Sadollah Nasiri1,2 1Physics Department, Zanjan University, Zanjan 45195-313, Iran; Institute for Advanced studies in Basic Science (IASBS), Zanjan 45195-1159, Iran; Measurement of light pollution 2 Introduction Among 34 candidate sites at the central part of the country, 5 sites namely Garkesh (in Kashan ), Kolahbarfi(in Kashan ), Deynava (in ... One of these is light pollution. ...

. Next: About this document ... Up: Part IV Extragalactic Astronomy Previous: Magnitudes . Sky brightnesses in magnitudes per square arcsecond. This data is from Siding Spring observatory - other observatories will be comparable or worse. U . B . V . R . I . J . H . K . Kn . Dark Sky . 22.8 . 22.5 . 21.5 . 20.8 . 19.3 . 6-day Moon ... 21.3 . 20.8 . 20.4 . 19.2 . Full Moon ... 18.8 . 18.5 . 18.9 . 18.2 . 15.0 . 13.7 . 12.5 . 13.7 . Paul Francis . 1999-03-09

Next: Feed Polarisation Up: Calibration Previous: Calibration Index . RPFITS files do not contain any information as to whether the telescope calibration was in units of Kelvin or Janskys. On reading the data a default value is set depending on the telescope and frequency of observation. ... ASAP>scans = scantable('2004-11-23_1841-P484.rpf', unit='Jy') # Or in two steps ASAP>scans = scantable('2004-11-23_1841-P484.rpf') ASAP>scans.set_fluxunit('Jy') . ...

This figure shows, on the left, images of Encke on three successive days from November 6 to November 8; on the right, images of ISON are shown for three successive days from November 9 to November 11. ... Green circles indicate some of the brighter cataloged background stars in each image; yellow marks bracket the comets. The background stars are fixed in each image from top to bottom, so the motion of the comet relative to the stars is clear in each case. ...

Once students get the hang of it, they can find and measure the brightness of Delta Cephei in a few minutes. ... of Delta Cephei . ... Oct. ... The following table lists the measurements of Delta Cephei made by one amateur astronomer in autumn 1990. ... 4.0 . ... This activity is a simplified version of one that appeared in Hands-On Astrophysics, a series of activities prepared by the American Association of Variable Star Observers with support from the National Science Foundation. << previous page | ...

... 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. ...