Australian Sky & Telescope - 04.2019

42 AUSTRALIAN SKY & TELESCOPE April 2019

BINOCULAR HIGHLIGHT by MatT Wedel

Cluster fit for a queen

S

outhern Hemisphere stargazers are lucky to have ready access

to many of the closest, brightest and best open star clusters,

especially in the period from early summer through to autumn.

You can take your pick of the far southern clusters — from the Jewel

Box to IC 2602 and NGC 3532. In the other direction, within 30°

north of the celestial equator are three famous clusters. Two of them,

the Pleiades and Hyades, you’ve no doubt seen on many occasions. But

have you spent some time enjoying the Coma Star Cluster?

If you look north in the evening this time of the year, you’ll find

the constellation Coma Berenices, or Berenice’s Hair. At culmination,

it is about 30° above the horizon for observers at the latitude of

Sydney. The constellation’s name honours Egyptian queen Berenice’s

sacrifice of her hair to the gods.

The queen’s legendary gift lies about 2° south of Gamma (γ)

Comae Berenices, in the form of the aforementioned Coma Star

Cluster, the glittering jewel of the constellation for naked-eye and

binocular observers.

Of the three clusters mentioned, closest to us at 150 light-years is

the Hyades, in Taurus, the Bull. Next comes the Coma Star Cluster,

at about 280 light-years, then the Pleiades at 440 light-years. The

Coma Star Cluster is about 20 light-years across, and the Hyades and

Pleiades each around 15.

I urge you to spend some time comparing and contrasting these

clusters with your binoculars and with your naked eyes. Whether

doing so inspires you to contemplate cosmic time and distance, or

simply to enjoy some of the finest sights in the night sky, it will be

time well spent.

■ MATT WEDEL is finding it a challenge to stuff even a small star cluster

into his brain. Binoculars certainly help.

–1

Star

magnitudes

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USING THE

STAR CHART

WHEN

Early March 10pm

Late March 9pm

Early April 8pm

Late April 7pm

These are standard times —

add Daylight Savings if it applies

to your location.

HOW: Go outside within an hour

or so of a time listed above. Hold

the map above your head with

the bottom of the page facing

south. The chart now matches

the stars in your sky, with the

circular perimeter representing

the horizon and the centre of the

chart being the point directly over

your head (known as the zenith).

FOR EXAMPLE: Look at

the chart, and you’ll see that the

bright star Achernar at the end

of the constellation Eridanus

(The River) is about one-third of

the way from the southwestern

horizon and the middle of the

chart. So if you look to the

southwest, you’ll find Achernar

about one-third of the way up

from the horizon.

NOTE: The map is plotted for

35° south latitude (for example,

Sydney, Buenos Aires, Cape

Town). If you’re much further north

of there, stars in the northern part

of the sky will be higher and stars

in the south lower. If you’re further

south, the reverse is true.

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ONLINE

You can get a real-time sky chart

for your location at

skychart.skyandtelescope.com/

skychart.php

M64

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COMA BERENICES Coma

Star Cluster

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