NOVEMBER 2018 OBSERVERS CHALLENGE – NGC-147  

Calculating the surface brightness magnitudes:  

Information from “Observing handbook and Catalog of Deep-Sky Objects” by Christian B. Luginbulh and Brian A. Skiff :  

“The surface brightness magnitudes (sfc. br.), also from the * RC2, represent the brightness (in V or B, depending on the color of the integrated magnitude ) of a square arc minute patch averaged over the galaxy within the dimensions given for each.  Since this value is an average, the central parts of the galaxy will typically have higher surface brightness and the outer parts lower.”

For complete information concerning (sfc. br.) refer to pages 10-11 “Observing Handbook and Catalog of Deep-Sky Objects.”   Luginbuhl and Skiff. 

* RC2 =  “….nearly all data on galaxies are from the Second Reference Catalogue of Bright Galaxies (RC2) by de Vaucouleurs, de Vaucouleurs and Corwin, and the Southern Galaxy Catalog (SGC) by Corwin, de Vancouleurs, and de Vancouleurs.” 

Observing notes and pencil sketches by Sue French from New York:

254/1494mm Newtonian

43×: By sweeping westward from Omicron Cassiopeiae, NGC 185 is immediately visible ensconced in a isosceles triangle of three 8th- to 10th-magnitude stars, the brightest one golden.

68×: The sketch was done at this magnification, where NGC 185 and NGC 147 just fit together in the 72 arcminute field of view.  NGC 185 has a small core that grows gently brighter toward the center. NGC 147 is more slender than its companion and very faint.  There’s a dim star superimposed on NGC 147, barely west of the galaxy’s center. Both galaxies lean roughly northeast by east, with plump NGC 185 have a slightly greater position angle. Most of the stars visible near the galaxies were sketched, but far too many showed in the richly populated Milky Way for me sketch all the field stars.   Sue French 

Pencil sketch with inverted colors:  SF 

Observing notes and pencil sketches by Roger Ivester

Pencil sketches:  

OCTOBER 2018 OBSERVERS CHALLENGE – NGC-7129

In my 10-inch reflector a cluster of four brighter stars with some fainter members, enveloped by nebulosity with greater concentration around the two northernmost stars.  The nebula has fairly high surface brightness, and easy to see at 57x, but best seen at 114x, and without any type of filter.  The sparse cluster and nebulosity is very easy to locate and see, and stands out prominently in the star field.    Roger Ivester 

Pencil sketch with inverted colors:   

SEPTEMBER 2018 OBSERVERS CHALLENGE – NGC-6818

Pencil sketch from the eyepiece using a 5 x 8 blank notecard, and 6-inch f/6 reflector @ 129x, with the colors inverted…