My first Magazine Sky & Telescope - 03.2019 | Page 33

Are you up for the ultimate observing
challenge? Take a page out of the author’s
logbook and endeavor to observe the whole
Herschel catalog.
I
n May of 1975 I completed my observations of all
110 Messier objects and received the certifi cate of the
Astronomical League’s (AL) Messier Observing Pro-
gram. There weren’t an y other deep-sky programs within
the reach of an amateur astronomer with a 6- or 8-inch
refl ector until James “Jim” Mullaney of Pittsburgh, Penn-
sylvania, in a letter to Sky & Telescope (S&T: April 1976, p.
235) soon proposed a new observing challenge: a list of the
brightest objects culled from William Herschel’s Catalogue
of Nebulae and Clusters of Stars. The Ancient City Astron-
omy Club of St. Augustine, Florida, reacted to Jim’s letter,
and the AL’s Herschel 400 Observing Program took off
( https://is.gd/Herschel400 ).
t TWO OBJECTS UNDER ONE NUMBER The Cone Nebula and the
Christmas Tree Cluster are both cataloged under a single designa-
tion: NGC 2264. These double (or even multiple) designations have led
to confusion in the past. The nebula and the cluster lie at a distance
of about 2,600 light-years in Monoceros. This image, taken with the
European Southern Observatory’s Wide Field Imager at the La Silla
Observatory in Chile, spans some 30 light-years.
William Herschel cat-
egorized eight classes of
object as shown at right.
Also tabulated are the
lower and upper limits
of number of objects in
each category that the
author collated from vari-
ous publications, as well
as the total.
Herschel’s Classes of Objects
Class
Type
Lower Limit Upper Limit
I Bright Nebulae 288 289
II Faint Nebulae 907 912
III Very Faint Nebulae 978 987
IV Planetary Nebulae, Stars with Burs, with Milky
Chevelure, with Short Rays, Remarkable S hapes, etc. 78 80
V Very Large Nebulae 52 53
VI Very Compressed and Rich Clusters of Stars 42 43
VII Pretty Much Compressed Clusters of Large (Bright) or
Small (Faint) Stars 67 67
VIII Coarsely Scattered Clusters of Stars 88 89
2,500 2,520
Totals
sk yandtele scope.com • M A RCH 2 019
Herschel’s
Categories
31