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Letters
in my front yard with a 5- and 8-inch
Schmidt-Cass. After retiring from 30
years of social work, I now fi nd myself the
lucky director of a small planetarium in
Ohio, where your magazine continues to
prove invaluable. I just fi nished reading
the March issue, but I fi rst read the online
version last week. The digital edition looks
For the Record
✹ The March cover story listed Simon Portegies Zwart’s institution as the University of
Amsterdam. He works at Leiden University in the Netherlands.
✹ In the timetable on page 69 of the February article “May’s Great Annular Eclipse,” the
times for Arizona were wrongly corrected for Daylight Savings Time. (Arizona does not
observe DST.) All times listed for Arizona should be one hour earlier. You can also go to
the map at eclipse.gsfc.nasa.gov to see predictions in Universal Time.
For a list of past errata, please go to SkyandTelescope.com/Errata.
75, 50 & 25 Years Ago Roger W. Sinnott
May–June 1937
Ghost Images “Not long ago the discovery
of a faint southern comet was announced [by
Harvard Observatory, relayed from a Southern
Hemisphere amateur astronomer]. But, alas!
there was no new comet. The experienced amateur
was not careful enough about the refl ection
in i his telescope from
the t nearby planet Mars.
He H had observed and
reported r a ghost. . . .
“[Ghost images] are
even e more dangerous
than t the nebulae and
star s clusters that try to
look l like comets, since
the t ghost will appear to
move in i the h course of fan
hour because of [the]
changing relative position of observer’s eye
and telescope . . . and this apparent motion of
an apparent comet so excites the observer that
judgment abandons him and he dashes for the
telegraph offi ce.”
Then as now, ghost images are usually caught
before the offi cial announcement of a new
discovery.
May 1962
Stellar Giant “One of the largest known stars
— the red supergiant component of the eclipsing
binary VV Cephei — has a diameter 1,620
times the sun’s, according to Indiana University
astronomer Benjamin F. Peery, Jr.
splendid, is well designed, and is easy to
navigate . . . but the paper copy I hold in
my hand is irreplaceable. Of course, that’s
only the opinion of one old guy.
iPhone-, iPad-, and Kindle-less at the
Hoover-Price Planetarium—
David L. Richards
Canton, Ohio
“This fi nding came
from f his spectroscopic
study s of the unusual 20.4year
y binary. . . . [Knowing
the t orbits’ sizes,] the
Indiana I astronomer could
evaluate e the diameter of
the t M star from the orbital
elements e and the known
duration of the eclipses. eclipse This red supergiant, he
fi nds, is so enormous that the orbit of Jupiter
could be fi tted inside it.”
Peery’s result holds up well today. VV Cephei
has just a few contenders for largest known star;
recent studies put it from 1,600 to 1,900 times the
Sun’s diameter, nearly the size of Saturn’s orbit.
May 1987
Neutrinos from Hell “Neutrino astronomy, for
decades the sole concern of theorists, became
a genuine observational science early on February
23rd. That day, a handful of these elusive
particles were detected from Supernova 1987A
in the Large Magellanic Cloud. . . .
“The observations represent
r the fi rst neutrino
detections d from a known
extraterrestrial e
source.”
Technical editor Ronald
A. A Schorn spearheaded
S&T’s S coverage of the nearest
e supernova observed in
modern m times.