Australian Sky Telescope MayJune 2017

42 AUSTRALIAN SKY & TELESCOPE May | June 2017

Hail to the King

J

upiter is this month’s target, for three reasons.

First, it’s the most rewarding planet to observe with

binoculars. Even at 7×, the King of Planets is a disk rather than

a point of light. But the real show is the four Galilean moons — Io,

Europa, Ganymede and Callisto — visible to either side (assuming

they’re not hidden behind the planet). At 15×, the major cloud belts

can be seen under good conditions. Once at a star party, I aimed my

tripod-mounted 15×70s at Jupiter. After looking for a long time, a

friend remarked, “With these, you hardly need a telescope!”

Second, it’s no exaggeration to say that observing Jupiter with

binoculars is the reason I write about astronomy. Back in 2007, I picked

up a stargazing guide on a whim. The book made a remarkable claim:

The moons of Jupiter were visible through binoculars. “No way!” But I

was intrigued, so I dug my old 7×35s out of the closet. I went outside,

focused on Jupiter, and behold: one bright light with little lights lined

up beside it. That was it for me. A few days later I had my first telescope.

Third, it’s fate. I know that celestial objects don’t control our

lives, but sometimes they give us hints. When I went to pick out

this month’s subject, the sky was half-covered with patchy clouds.

I needed to get my bearings, so I started with a bright star peeking

out in the east. Was it Arcturus? Spica? No, it had a companion, had

to be a double star. Wait, more companions? Oh, I get it — Jupiter! I

was unreasonably happy, to have accidentally repeated my first-ever

observation, a decade after the original.

„MATT WEDEL likes to kick back with his binoculars on a driveway.

–1

Star

magnitudes

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USING THE

STAR CHART

WHEN

Late April 11pm

Early May 10pm

Late May 9pm

Early June 8pm

Late June 7pm

These are standard times.

HOW

Go outside within an hour or so

of a time listed above. Hold the

map out in front of you and turn

it around so the label for the

direction you’re facing (such as

west or northeast) is right-side up.

The curved edge represents the

horizon, and the stars above it on

the map now match the stars in

front of you in the sky. The centre

of the map is the zenith, the point

in the sky directly overhead.

FOR EXAMPLE

Turn the map so the label

“Facing SW” is right-side up.

About a third of the way from

there to the map’s centre is the

brilliant star Canopus. Go out

and look southwest nearly a

third of the way from horizontal

to straight up. There’s Canopus!

NOTE

The map is plotted for 35° south

latitude (for example, Sydney,

Buenos Aires, Cape Town). If

you’re far north of there, stars

in the northern part of the sky

will be higher and stars in the

south lower. Far south of 35°

the reverse is true.

ONLINE

You can get a real-time sky chart

for your location at skychart.sky-

andtelescope.com/skychart.php

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Jupiter,

May 15,

2017

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BINOCULAR HIGHLIGHT by Mathew Wedel

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