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The Year-round Messier Marathon Field Guide: Author: Harvard C. Pennington



In the forward to this book Perry W. Remaklus describes Harvard Pennington as a tireless promoter of the Messier Marathon. Pennington envisioned the marathon as a means of encouraging amateur astronomers, to promote their growth as observers. Unfortunately he died of heart disease prior to the publication of this book.

The Messier Objects are 110(109 with one duplication) deep sky objects discovered by, or attributed to, Charles Messier, an 18th. century French Astronomer. Messier’s catalogue, was intended as a guide to objects he felt could easily be confused with comets. The Messier Marathon was conceptualized by a group of Spanish amateur astronomers, in the 1960’s. This concept further evolved in the U.S. in the late 1970’s, as “…an informal competition to locate the most Messier objects by a single observer during a dusk-to-dawn Marathon.” The author, Harvard Pennington, conducted his first Messier Marathon in March of 1987, having previously been able to locate less than forty of these deep-sky objects. The methods he developed for this first Marathon, and refined for subsequent ones are summarized in this book.


1x Finder Chart

The book is intuitively organized and written in a clear, easy to read style. As a relative newcomer to the hobby I found the text easy to follow and understand. Early chapters cover the logistics of a Marathon, discussing timing, venue, and basic knowledge of equipment. This is followed by a discussion of the essential elements of Pennington’s technique, finding objects through pattern recognition. He presents, in chart form, essential constellations, asterisms and stars which function as “Celestial Signposts”. The use of a Telrad (1x magnification, reflex finder), as an essential tool, is then reviewed. Having covered these basics Pennington describes a method of locating Messier objects called “The Geometric Method”. Initially, using a Telrad finder, he drew circles, representing the 4 degree outer circle of the finder, on a SkyAtlas 2000.0 chart. He noted “…the same geometric relationship to the reference stars in the sky.” Essentially, his technique relates the field of a reflex finder, centered on a target object, to a patterned grouping of stars, usually a constellation or easily recognizable asterism. Pennington then describes the application of this approach to magnified finder scopes and alternative finders, including some homemade varieties.


8x50 Finder Chart

The “Field Guide” next provides an overview of the Messier Objects, grouping them by category, and locating difficulty. The book then concludes with a series of sequential finder charts, to be used in conducting a Messier Marathon. These charts include:

  • One-Power Finder Charts, showing finder constellations, with superimposed 4 degree Telrad circles centered on target objects. Again these form the basis of Pennington’s “Geometric Method”.
  • Supplemental charts, showing fields of view, through typical finder scopes, plus sketches of eyepiece views.
  • “ Eyepiece Starhopper Charts” for finding difficult to see objects at twilight.
  • Further starhopper charts for finding objects that may be difficult to locate by the “Geometric Method”
  • A series of starhopping charts for finding the “Virgo Cluster” of galaxies.

How well does all of this work? Like the author’s early experience, I have found locating deep sky objects painstaking and often frustrating. Light polluted, and smog hazed Toronto skies complicate the process. The temptation to rely on “Go-To” technology is persuasive, but I worry that reliance on this technology hampers learning the night sky and its relationships. A methodical approach to systematically learn, through the satisfaction of finding new objects, is something that I have sought.


Starhopper Chart

To evaluate Pennington’s “Geometric Method” I set up my LX200GPS( aperture = 254 mm or 10”, focal length = 2500 mm, focal ratio = 10, Schmidt-Cassegrain). I used a Teleview Panoptic 35 (focal length = 35mm, apparent field = 68), which yields magnification and field of view as follows:

Telescope Focal Length/Eyepiece Focal Length = Magnification, i.e. 2500/35 = 71.4x

Apparent Field/Magnification = True Field, i.e. 68/71.4 = .95 degrees

Pennington suggests that a telescope-eyepiece combination yielding a field of view of about one degree is ideal. The default viewing site was the driveway in front of my house, replete with street lamps, overhanging trees and the pall of neighbors coach lamps. After the scope completed its alignment routine I turned to the Ursa Major charts, since this constellation was overhead, unobstructed and not aligned with outdoor lighting. The sky was clear, but hazy, so viewing was not ideal. Chart 21 showed M106 at the corner of a triangle, with one side passing from Dubhe through Phad at roughly two times the distance between these two stars. I manually slewed the scope until the angles and relationships in the Telrad matched the chart. There, in the field of a Panoptic 35, was an oblique fuzzy streak, not dead center, but close. I then slewed to about one telrad circle(4 degree outer circle) above Megrez, looking for M40. In the Panoptic a faint double star appeared, but no galaxy. I went back to the finder page in the book, and realized my error. The double was M40, while the faint galaxy that I was hunting for, was actually NGC 4217. At visual magnitude 12.7, even at a dark site, this would have been difficult to find. Using other charts produced mixed results, probably due to the limitations of the observing site. Overall I was satisfied. With practice and a proper viewing site the charts should produce more consistent target hits.

In summary, I would highly recommend this book. Observers, planning to participate in a marathon, or seeking to improve their navigational skills, can benefit from its varied selection of charts. The text is readable, logical in its flow, and easily understandable. Criticisms are few. The pages are printed on porous paper, that seems to soak up dew, a problem for a book that begs to be used in the field. Perhaps more attention should be given to a discussion of starhopping as a technique, since the author admits that not all Messier Objects, are amenable to his “Geometric Method”. Lastly, why must fronts bearing bad weather all be blamed on Canada.

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