Sky and Telescope - June 2016 - 37

MODERN CONFIRMATION Today, backyard amateurs with
modest gear far surpass the greatest astrophotographers of
120 years ago. Even without narrowband ﬁlters, the intricate
clouds around 15 Monocerotis (S Monocerotis) and the Cone
Nebula stand brilliantly revealed in Andrew Lecher's stack of 54
ten-minute exposures. He took 18 each through red, green, and
blue ﬁlters. The frame is 1°° tall, with north up. The upside-down
Christmas Tree asterism spans most of the nebula, with 15 Mon
as the tree's base and the bright star just north of the Cone
Nebula as its tip.

was a "conical dark space bounded by a rim of nebulosity" - the now-famous Cone Nebula - just south of a
larger, triangular bevy of stars now named the Christmas Tree Cluster.
Roberts then projected a second lantern slide of the
same region, this one from a glass photographic positive
that had recently arrived from the United States. The
photographer - Lick Observatory's Edward Emerson
Barnard - was, like himself, a widely acknowledged
expert in astronomical imaging. Although the pair of
images depicted identical regions, they looked distinctly
diﬀerent. The stars in Roberts's photograph, taken with
his 20-inch telescope, were virtual pinpoints. Those in
Barnard's picture, taken with Lick's 6-inch, f/5.2 wideﬁeld Willard camera, appeared as bloated disks.
Roberts acknowledged that he had enlarged Barnard's
photograph ﬁvefold to match the scale of his own. He
had done so to make a point. The profuse "nebulosity"
depicted in Barnard's image was illusory, he argued;
it stemmed from the poor resolution of the Willard
camera, which captured large swaths of sky at a highly
compressed scale. Through his own 20-inch reﬂector, he
said, the purported nebulous glows and swirls in the star
cluster are seen for what they are: aggregations of faint
stars, entirely beyond the feeble light grasp of Barnard's
little instrument.
Unwittingly or not, Isaac Roberts had ﬁred a transatlantic salvo from an amateur astronomer's station
south of London into the heart of a professional research
institution in California. The return volley from Barnard
was not long in coming.
E. E. Barnard was the product of an impoverished,
hardscrabble upbringing in Tennessee during the Civil
War. He was a high-strung workaholic who had just
two months of formal schooling before he took a job as
a studio photographer's assistant at age nine. Barnard
learned astronomy in his teens from Thomas Dick's
popular handbook The Practical Astronomer. He became
a passionate hunter of comets, discovering 16 of them
altogether, and built a house for himself and his bride
with the reward money that was oﬀered at the time to
comet ﬁnders.
In 1888, after a ﬁve-year stint as a non-degree student
and observatory manager at Vanderbilt University,
Barnard joined the staﬀ of the new Lick Observatory in

15 Mon

Fox Fur Nebula

Cone Nebula

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Sky and Telescope - June 2016

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