... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. November 28, 1998 . A Lonely Neutron Star . ... Explanation: How massive can a star get without imploding into a black hole? ... Assuming that the object is a neutron star of typical mass, some previous theories of neutron star structure would have predicted an implosion that would have created a black hole . ... About APOD > . ...

... Assured of a reliable method of solving the normal equations, we now consider the equations of condition. The observed magnitude m of a star at M air masses with true instrumental magnitude is modelled as ([ 10 ], [ 28 ]) . ... The effective extinction coefficient depends on the effective spectral gradient [ 29 ] of the star, for which we use some color index, affected by half the atmospheric reddening ([ 26 ], [ 10 ]): . ... Thus, for the B band of UBV, we use the (U-V) color. ...

... CIMAFITS is the name for the Arecibo FITS-file format. ... This is a list of (fairly) up-to-date documents describing CIMA and CIMAFITS: . The CIMA version history log which is the most up-to-date page listing all changes made to the different versions of CIMA . ... The CIMA user's log which chronologically lists changes made to CIMA that may be relevant to an observer. The CIMA engineering log which lists engineering changes made to CIMA that probably are of less interest to an observer. ...

... ESO, the European Southern Observatory . ... Travel and Contacts . ... Green ESO . ... Survey Telescopes . ... 2002 . ... Images of Titan taken on November 26, 2002 through nine different filters to probe different altitudes, ranging from the stratosphere to the surface. ... Due to these good observing conditions, Titan's trailing hemisphere was observed with contrasts of about 40%, allowing the detection of several bright features on this surface region, once thought to be quite dark and...

... Let us first find out which way -- rise in spectral resolution with some loss in the S/N ratio or increase in the S/N ratio with a fixed spectral resolution -- is better for the purpose of reduction of equivalent width determination errors. ... N -- number of counts for 1 ? ... line equivalent width, . ... Thus if the spectral resolution is managed to be increased (i.e. to decrease )without loss in the number of counts falling at 1 ?, the equivalent width measurement error is then proportional to . ...

Describes how spatial region boundaries are handled. The golden rule for spatial region filtering was first enunciated by Leon VanSpeybroeck in 1986: . ... With this in mind, the rules for determining whether a boundary image pixel or table row are assigned to a region are defined below. For image filtering, pixels whose center is inside the boundary are included. ... That is, an row is inside the boundary without regard to its integerized pixel value. ...

... Images obtained using the Faulkes Telescope South, operated by Las Cumbres Observatory. ... The Faulkes Telescope Project and Las Cumbres Observatory Global Telescope Network had kindly given us the opportunity to use these telescopes and the observatory had booked us four sessions of controlling the telescope in order for us to make some observations on NEOs. ... Just before our first observing session on Friday, we were given a tour of the observatory building and its telescopes, by John McFarland...

spaceweb@oulu.fi - last update: 27 November 1998, 1900 UT (RR) . Tailward fast plasma flows with dipolar Bz signatures (north-then-south turning of B) observed within plasma sheet are called plasmoids (e.g., Hones et al., ... Most plasmoids have also helical magnetic field structures (large By fields), called "flux ropes" (Hughes and Sibeck, 1987; Slavin et al., ... 1998). ... Observations of plasmoids are highly correlated with substorm onsets (Moldwin and Hughes, 1993; Nagai et al., ... Lett. ...

The conference program included eleven one-hour talks and four free discussions. ... The talk also discussed different models for Internet traffic and quality of Service measures. ... The talk by Nikolai Vereschagin (Moscow State University) "The Kolmogorov complexity of approximate descriptions" discussed different notions of descriptive complexity of computable sequences which can be used in Internet measurements. ... What mathematics does Internet need?" ...

Next: The Scenario Machine: Operational Up: Evolution of Magnetic Rotators Previous: Ejector-propeller hysteresis . ... The length of this segment is determined by the eccentricity. ... In this case no hysteresis occurs and transitions E -- P and the reverse take place in symmetrical points of the orbit. ... Here EP means a mixed state of the rotator at which it is in the ejector state during one part of the orbit, and in the propeller state during the rest of the orbital cycle. ...

... A Colorful Moon . ... But small, measurable color differences have been greatly exaggerated to make this telescopic, multicolored, moonscape captured during the Moon's full phase. ... In most places on Earth, a lucky viewer.. Geminid Meteors over Teide Volcano . ... Gibbous Europa . ... In fact, this gibbous phase shows part of Jupiter's moon Europa. ... The Bubble Nebula . ... Cataloged as NGC 7635, it is also known simply as The Bubble Nebula. ... What will survive this battle of the galaxies? ...