... March 24, 1996 . Comet Hyakutake's Closest Approach . ... Explanation: The above true color image of Comet Hyakutake was taken the night of March 21/22. Tonight, Comet Hyakutake will make its nearest approach to Earth, closing to a mere 10 million miles as it passes over the planet's Northern Hemisphere . ... For the rest of March and most of April Comet Hyakutake will be visible to Northern viewers (weather permitting). ... Comet Hyakutake Finder Chart . ... About APOD | ...

... 2001 January 18 . 2001: A Total Lunar Eclipse . ... Explanation: The first and only total lunar eclipse for the year 2001 occured on the evening of January 9/10 as the full Moon glided through Earth's shadow. ... The fact that the northern (top) portion of the eclipsed Moon is clearly brighter, even near mid-totality, demonstrates that Earth's shadow is not uniformly dark. Tomorrow's picture: Black Holes Are Black . ... About APOD | ...

This page is devoted to information on Supernova 1999gi in NGC 3184 . ... Information on the original web pages for many of these images can be found on the Supernova links web page. ... NGC 3184 is a fairly close Mag 10.3 galaxy, only about half as distant as the Virgo cluster. ... Seiichi Yoshida has a 1999gi page . Odd Trondal's 1999gi page . ... CfA image . ... 14.5 . ... Jean Marie Llapasset image . ... vsnet-alert 3805 ] SN 1999gi in NGC 3184 . vsnet-chat 2438 ] Host galaxy of SN1999gi . ...

Prague, August 16, 2006 . ... Large classes (groups of types) : . ... Eruptive variable stars . ... Pulsating variable stars . ... Rotating variable stars . ... Cataclysmic (explosive and nova-like) variables . ... Close binary eclipsing systems . ... Optically variable close-binary sources of strong variable X- ray radiation . ... These classes are just a way to group types; in our opinion, they can be kept if slightly better described ( e.g ., remove close from item 5, simplify item 6) ...

ABSOLUTE PROPER MOTIONS OF 331 OPEN CLUSTERS . ... The proper motions of stars in the fields of 331 open clusters were taken from Four-Million Star Catalog (4M-catalog) of positions and proper motions (Volchkov et al. ... The absolute proper motions for 21 young open clusters have been derived by comparison of precise relative proper motions of individual stars and their corresponding absolute proper motions. ... Sign of proper motions in RA . ... 0.0001 arcsec/yr . ... rms error in RA proper motion . ...

... The distance scales of the objects are matched both by comparing the first derivatives of the angular velocity determined separately from radial velocities and proper motions and by the statistical-parallax method. ... Good agreement between the inferred 0 and our calculations based on space velocities suggests that the Lindblad relation holds throughout the entire sample volume. ... Brandt and Blitz (1993) published the distances and radial velocities for a total of 206 H II-regions. ... Astron. ...