Sky & Telescope - April 2021 - 6

FROM OUR READERS

Being a bino nut myself, I enjoy reading Matt Wedel's Binocular Highlight
column. I also enjoy the observing
articles he writes. So I plowed into
" The Caldwell Catalog Turns 25 "
(S&T: Dec. 2020, p. 20) with interest -
most enjoyable! I've ignored the catalog
since it came out, but after reading his
article, I may give it a try!
I had the pleasure of meeting
Patrick Moore in 1986 on a two-week
tour in Australia to see Halley's Comet.
The people on
the trip were split
between three
buses, and each
had a different
tour leader. I
lucked out - PatS Patrick Moore and
rick Moore was
Bill Dellinges pose
our guide! I knew
for a picture during
of his fame, so I
a two-week tour in
was delighted.
Australia in 1986.

Bill Dellinges
Apache Junction, Arizona

Although Matt Wedel averred that
the goal of his article was " not to
focus on his [Patrick Moore's] political opinions, " he nevertheless chose to
mention them and made it clear that
he disagreed with Moore's views.
Some other aspects of Patrick
Moore's life that may not be well
known to fans of his astronomical
contributions are that he was a keen
follower of cricket, a more than competent performer on the xylophone,
and a staunch and vocal opponent of
fox hunting.
Jeremy Tatum
Victoria, British Columbia

Sketching OB Associations

Cruising Under Totality

I enjoyed reading Matt Wedel's " The
Fires of Youth " (S&T: Jan. 2021, p. 43).
Years ago, I visually sketched my way
through a number of OB associations listed in the article " In Pursuit
of OB Associations " by Joseph Caruso
(S&T: Jan. 1986, p. 110).
I have more sketches of OB associations and star charts on my website:
stellar-journeys.org/OB-Tour.htm.
One of the reasons that I really enjoy
reading S&T is the wonderful observing
articles covering a wide range of objects
suitable for small and large telescopes.
Barely an issue goes by where I'm not
cutting out and saving something for a
future observing project!

Rick Fienberg's " Corona Virus "
(S&T: Jan. 2021, p. 84) brought back
fond memories of two special cruises.
Having never seen a total solar eclipse
before, my wife and I planned to observe
the July 11, 1991, one in Hawai'i. We
luckily found ourselves off the shores of
Mazatlán, Mexico, on Carnival Cruise
Line's Jubilee to watch the event. Buzz
Aldrin was a guest lecturer! It was a
fantastic cruise experience.
Then, during the February 26, 1998,
eclipse, we were on Carnival's new,
larger Fascination near Aruba. Although
totality was shorter on this cruise, it
had two brilliant " diamond rings " !
Each cruise also had a great captain.
And both cruises were full of friendly
people and pure enthusiasm - the
cheering as darkness fell!

Larry McHenry
Pittsburgh, Pennsylvania
W Larry McHenry
observed Orion OB-1a
on January 29, 1993,
through an 80-mm
(3-inch) refractor with
a 32-mm (1.25-inch)
eyepiece and drew this
sketch of what he saw.

6

What a walking encyclopedia! The
guy could (and did) lecture on any
astronomical subject off the top of his
head. I was in heaven.

APRIL 2 021 * SK Y & TELESCOPE

John Kuczek
Vero Beach, Florida

The Formation of Planets
The impression that I got from Edwin
Bergin's article " Follow the Carbon "

(S&T: Dec. 2020, p. 34) is that the
amount of carbon an Earth-like planet
in the habitable zone of a star system
winds up with is highly dependent on
the circumstances and history of that
star system. It could range from almost
no carbon to a signiﬁcantly greater
percentage of carbon than Earth has. As
we continue to investigate, we should
expect the unexpected.
James Scott
Vernon, New Jersey

Einstein Rings
Thank you for Monica Young's News
Note " 'Dead Ringer' for the Milky
Way Found in the Early Universe "
(S&T: Dec. 2020, p. 10). It takes a
remarkable alignment of the foreground and background galaxies to
produce such a symmetrical ring.
Your article triggered a thought
that I should have had years ago, when
Einstein rings were ﬁrst observed:
Where is the foreground galaxy? I can
roughly understand the physics of the
ring formation, but what happens to the
foreground galaxy's light?
It seems that it should be visible
somewhere, maybe in the center of the
one shown and off-center in less symmetrical rings or arcs.
Phil Petersen
League City, Texas

"

Monica Young replies: That's a

really good question! In this case,
the foreground galaxy is invisible because
it doesn't emit much light at the speciﬁc
wavelength the scientists are looking at.
Francesca Rizzo and colleagues used the
Atacama Large Millimeter/submillimeter
Array (ALMA) to look at emission from ionized carbon in the background galaxy. This
spectral line is emitted at 158 microns, but
the background galaxy is so far away (redshift 4.2), that the wavelength stretches to
826 microns (0.8 millimeter) by the time
it passes through the expanding universe
to reach Earth. The foreground galaxy, at
redshift 0.2, doesn't emit much light at
this wavelength, so it's not visible in the
ALMA image.
However, in other images of lensed galaxies, such as those taken by the Hubble

DELLING ES A ND M OORE: BILL DELLING ES

Patrick Moore's Caldwell Catalog
http://stellar-journeys.org/OB-Tour.htm
Sky & Telescope - April 2021

Table of Contents for the Digital Edition of Sky & Telescope - April 2021
