| Profile for North and East | |
| Who Am I: | Peter R |
| Where Am I: | 39 55' N, 116 25' E and sometimes in England (usu in Northumberland 55 N, 1 W) |
| About Me: | These are the astronomical observations/musings of a novice astronomer in a heavily light and air polluted urban environment and, occasionally, in better conditions elsewhere. Unless otherwise noted, observations are made with an ETX-90 with 26mm Super Plossl eyepiece. Sketches are mirror image. |
| Something Extra: |
ETX-90PE Manual: http://www.buytelescopes.com/manufacturers/meade/ETX_premier_edition.pdf Optical Design Maksutov-Cassegrain Primary Mirror Diameter 96mm (3.78") Clear Aperture 90mm (3.5") Focal Length, Focal Ratio 1250mm f/13.8 Near Focus (approx.) 11.5 ft. (3.5m) Resolving Power (arc secs.) 1.3 Optical Coatings MgF2; standard aluminum/SiO Limiting Visual Stellar Magnitude 11.7 Image Scale 1.16°/inch Maximum Practical Visual Power 325X Optical Tube Dimensions (dia. x length) 4.1" x 11" (10.4cm x 27.9cm) Lenses: FL(mm) Magnification Meade 4000 Super Plossl 9.7 128.8659794 15 83.33333333 20 62.5 26 48.07692308 Celestron Plossl 32 9 6 4 Lens details for ETX-90: http://dvaa.org/php/EppList.php?flMm=1250&diaMm=90&tName=Meade+ETX+90&noTwos=on Binoculars: Specification 10x50WA Field of view 6.5° |
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| This blog has moved to http://cityobs.blogspot.com | ||||
