... Four types of galaxy environments are considered: clusters, centers of groups, other places in groups, and the field. ... In order to check whether the mean ages of the stellar populations depend on environment density monotonically, as the hierarchical par­ adigm predicts, in this work I consider four types of environment separately: the cluster galaxies, the brightest (central ) galaxies of groups, the second­ranked group members, and the field galaxies. ... Group center SB(rs)0# 204 637 1996 Oct ...

... Guider functions . ... Guide Sensor Performance . ... Guide Sensor Sky Coverage/ Star Availability . Guide Star Selection Criteria . ... Guide fiber organization and reach at plug plate . ... Plug plate holes for guide stars are identical to those for science FO . ... FOV for each of 9 guide stars is 7.4 arcsec dia. (0.45 mm FO, Sumitomo IGN-05/10) . ... Selected guide stars must have no neighbor stars within TBD (5 arcsec) radius that have a brightness within TBD (5 mag.) of guide stars . ...

... More Than Just a Planet, It's a Meal . ... Can a star swallow a planet? ... Planets like Jupiter, it was thought, could not form that close to a star because the high temperatures there would have prevented "icy" and "rocky" solids from condensing out of the gas. ... The heavy element enrichment of a more massive star's surface by a Jupiter-like planet (which did not completely dissolve in the convection zone) could range up to 50% if the planet's heavy elements were uniformly distributed. ...

... 000, 1­12 (2009) Printed 11 February 2010 A (MN L TEX style file v2.2) Analytical approximations of K -corrections in optical and near-infrared bands I1gor V. Chilingarian1 2 ,2,3 , Anne-Laure Melchior 1,4 and Ivan Yu. ... Received 2010 February 01; in original form 2009 August 14 ABSTRACT To compare photometric properties of galaxies at different redshifts, the fluxes need to be corrected for the changes of effective rest-frame wavelengths of filter bandpasses, called K -corrections. ... Table 1. ...