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. ...

... 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. ...

Next: Conclusions Up: Compensation for Read-Out Noise Previous: Implementation . ... The star cluster, shown in the left panel of Fig. 1 , consists of a field of unresolved stars at random locations and having randomly selected brightnesses. ... These are replotted in Fig. 8 to facilitate comparisons. ... The low level noise is reduced substantially in Fig. 11 , which is the average of 25 restorations of HST star cluster images, each being the result of performing 500 EM iterations. ...

. 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

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... A sketch for the active region model on ultracool dwarfs. ... An active region model was built, based on the rotation of the UCD and the ECMI mechanism. ... The active region model is applied to the radio emission from TVLM 513-46546, in which the ECMI mechanism is responsible for the radio bursts from the magnetic tubes and the rotation of the dwarf can modulate the integral of flux with respect to time. ...

The CHIANTI database consists of 4 primary ASCII files for each ion in the database. contains the energy levels in cm^(-1) It includes both experimental data and theoretical values of the levels energies. ... Wavelengths are based on experimental level energies where available; wavelengths calculated from theoretical energies are less accurate and are given as negative values. ... contains the spline fits to the electron collision strengths scaled according to Burgess and Tully (1992). ...

A bright supernova, 1998S, has been found on March 3 by Chinese astronomers at Beijing Observatory. 1998S is located in NGC 3877 an UMa galaxy at R.A. = 11h46m06s, Decl. = +47o29'.0. ... Recent magnitude estimates show the star at around magn 12. ... It covers a field of 35'x35' and shows stars down to magnitude 15 and is mainly based on the GSC and USNO catalogues. ... Below follows a list of field and sequence stars located within ~20' from SN 1998S in NGC 3877: . ... TI (b-r)=+0.5 . ...

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) . ...

... It is found that the correlation coefficients between these two parameters calculated separately inside and outside the sunspot formation zone ±30 have cyclic variation and occur in anti-phase. This suggests different mechanisms of formation of the corona in the fields of small, medium, and large scales. ... The relationship between the coronal green line brightness (CGLB) and the magnetic field strength (MFS) has been investigated by constructing the corresponding synoptic maps for the 1977-2001. ...

. Next: References Up: Radiation processes and geometry Previous: Curvature radiation . љ . Very high brightness temperatures . Mechanism must be coherent . Bunches of particles both moving in the same direction and radiating in phase . Radiated power (number of electrons) . Jon Bell . Thu Dec 19 15:15:11 GMT 1996

... Three ` flavours'of binning and discard: · Discard 9 rows , readout 1 row, cut 10:1, resolution 1.75ms · Discard 90 rows , bin 10 rows , cut 10:1, resolution 2.76ms · Discard 95 rows , bin 5 rows , cut 20:1, resolution 2.76ms · Compared with normal timing : · 100 rows and readout, no cut, resolution 1.75ms Bin · Tested on XMM on Crab during rev 333 - 3 October 2001 Crab - rev 333 - Bright timing ... Counting mode and FIFO full errors. ... Crab - rev 333 - Bright timing mode ...

... Flux density at 1 GHz (/Jy): 210 . ... Optical: Large filamentary loop, brightest to the NE, not well defined to the S or W. X-ray: Shell in soft X-rays. ... ADS . ... IRAS observations. ... 1986, ApJ, 306, 266. ... VLA at 1.6 GHz (4".7) plus optical. ... Levenson et al. ... ROSAT and optical observations of W. ADS . ... ROSAT observations of N. ADS . ... ASCA observations of compact X-ray source in S. ADS . ... ROSAT images. ... 2002, A&A, 389, L61. ... Optical and ROSAT observations of region in...

This all-sky image, constructed from 2 years of observations by NASA's Fermi Gamma-ray Space Telescope, shows how the sky appears at energies greater than 1 billion electron volts (1 GeV). Brighter colors indicate brighter gamma-ray sources. ... A diffuse glow fills the sky and is brightest along the plane of our galaxy (middle). Discrete gamma-ray sources include pulsars and supernova remnants within our galaxy as well as distant galaxies powered by supermassive black holes. ...

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 | ...

... Credit: L. Drissen, J. Roy and C. Robert ( Universite Laval ), Y. Dutil ( CFHT ), NASA Explanation: These two clusters of bright, newly formed stars surrounded by a glowing nebula lie 10 million light years away in the dim, irregular galaxy cataloged as NGC 2366. ... A comparison with ground based images indicates that in three years this star's brightness increased by about 40 times making it currently the brightest star in this dim galaxy . ... Publications with keywords: stars . ...

... 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. ...

. 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

Subject, Problems and Objects of Theoretical Astrophysics. ... Stellar Photospheres, Their Features. ... Physics of Continuous Radiation Absorption in Stellar Photospheres. ... Continuous Radiation Absorption in Stellar Photospheres of Various Spectral Classes. Solar Type Photospheres. ... Characterisics of Absorption Lines. ... Interstellar Absorption Lines, Their Features. ... Physical and Dynamic Features of Interstellar Medium, Which Follows from Observations of Interstellar Absorption Lines. ...

Microsymposium 38, MS083, 2003 (A4 format) MERCURY: LOCAL VARIATIONS OF THE PHOTOMETRIC RELIEF. ... Because of trajectory and pointing angle constraints the planet could be observed from Mariner 10 only over a small range of phase angles between about 75o and 110o. Therefore the photometric investigations are restricted to measuring the distribution of brightness on the Mercurian disk. ... Raw versions of real-time processing pictures FDS 0000984 and FDS 0000986 were used (images 196 and 202). ...

... This program was created for correlating chosen regions in the series of fts images. ... Chosen regions' . ... In this section the program counts the integral for each region of the grid for each image. ... As a matter of fact, the integral is total brightness of the region and it is counted by 'int_tabulated' IDL function. ... In addition, the program will show the count of the regions which correlate with the corresponding region (the brighter region means the bigger count) and its contour. ...