The sky background can contribute significant Poisson noise in broad and medium band filters, and must be taken into account during noise calculations. The actual sky brightness depends on the heliocentric ecliptic coordinates (latitude and longitude) in a manner summarized in Table 6.3 . ... 22.4 . ... An average sky brightness of V=22.9 mag arcsec -2 is assumed. ... Values for other filters or sky brightnesses can be computed from Table 6.2 , Table 6.1 , Table 6.3 , and Equation 6.2. ...

Proceedings of the XXVIIth Young European Radio Astronomers Conference (YERAC). ... Please Note: e-mail addresses and external links in these contributions were correct when these papers were written in 1995, but may no longer be valid. ... In addition to the hypertext version of each paper, indicated by the link from the title of the paper, there are links to postscript versions of each paper, which are suitable for printing if you want a hardcopy of a given paper. ... Sandor Frey (or postscript ) . ...

... Proposing for VLBI Time at Arecibo . ... Documentation (Field System, VLBA4 terminal, Mark 5 system) . ... In 2001, the Arecibo Observatory received its hybrid VLBA-MARK IV (VLBA4) data acquisition system, and currently NAIC commits Arecibo to support VLBI observing up to a maximum of 4% of the 305-m's observing time. ... Tracking Time (h:mm) . ... The inclusion of the 305-m Arecibo radio telescope can dramatically boost the sensitivity of VLBI observations, even with its limited source tracking...

... Professor Esko Valtaoja (Turku University, Director of Tuorla Observatory): "The problem of high-energy emission from AGN" . ... Associate Professor Harry Lehto (Tuorla): "Radio observations of GRS1915+105" . ... Dr. Alexander Riehokainen (Tuorla, Academy Researcher): "Multiwavelength observations of the Sun over a full activity cycle" . ... Ilona Torniainen (Metsahovi, PhD student): "Inverted-spectrum radio sources" . ... A Study of solar polar zone using eclipse data with RATAN-600 . ...

... In these pages we have collected contributions by fellow amateurs supernovae hunters. These contributions concern mainly the discoveries they made and their searching activity. ... External link) . The discovery of SN1997bp in NGC 4680 (from TA Magazine, vol34, n.397) - text and images. Visual Supernova Searching With The 40 inch Telescope at Siding Spring Observatory . ... A web page on SN1995G in NGC 1643 (external link to the South Australia Astronomical Society) - text and images. ...

ATNF Home . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Staff list | ... Parkes radio telescope . ... Australia Telescope Online Archive (ATOA) . ... VLBI . ... CSIRO ATNF Data Archives . ... Visiting Parkes radio telescope . ... Parkes radio telescope webcam . ... This message : [ Message body ] [ More options ( top , bottom ) ] . ... I have not heard from anybody from the VLBI community wrt the Parkes instrumentation changes and I don't believe Hayley has either. ...

SAS home . ... EPIC background spectra are normally extracted from regions of the observation field-of-view, once "contamination" due to individual discrete celestial sources has been removed. ... In order to cope with this situation, blank sky event lists can be downloaded from the XMM-Newton Science Operations Center web site. ... It is in principle possible as well to extract background spectra from blank field event lists, if the spectrum accumulation regions are defined in sky coordinates. ...

... He made observations of a supernova (literally: nova= "new star") in 1572 (we now know that a supernova is an exploding star, not a new star). ... Brahe's meticulous observations showed that the supernova did not change positions with respect to the other stars (no parallax). ... This was early evidence against the immutable nature of the heavens, although Brahe did not interpret the absence of parallax for stars correctly, as we discuss below. Brahe made careful observations of a comet