Skywatch - 2021 - 9

Using Our
Sky Maps

Getting Oriented
First, fi nd the right
map for your time
and date. Start with
the page for the current month and check the
dates and times in the top-left
corner of the page.
Go outside within an hour
or so of the time listed for your
date. Bring a red-light flashlight along to read your map
by. Dim red light won't spoil
your night vision.
Once outside, you need to
know in which direction you're
looking. If you're unsure, just
remember where the Sun sets
- that's roughly west. Now
look at the yellow direction
labels around the map's edge.
Turn the map around so the
label for the direction you're
facing is right-side up, like
"Facing SE" in the example
below. That edge of the map
is the horizon in front of you.
The stars above it will match

Here's how to use the monthly
sky maps on the following pages
to identify your evening stars and
constellations.
By the Editors of SkyWatch

Can you spot Orion?
How about the Big Dipper? Can you
identify the North Star or the Pleiades?
The fi rst step into amateur astronomy is
learning the stars in your evening sky.
Once you meet them, they'll be your
companions for life.
And they'll be the framework for
fi nding everything fainter that you can
hunt with binoculars or a telescope.
Starting on page 13 are twelve large,
circular sky maps, for the evenings of
each month for the entire year. These
are your roadmaps for exploring the
universe from your backyard.

the stars you're
facing. (For now,
ignore the parts
of the map that
correspond to
other directions.)
The farther in from the
map's edge a star is plotted,
the higher it'll be in your sky.
Halfway from the edge to the
center means about halfway
from the horizon to straight
up. The map's center is the
zenith: directly overhead.
For each map, the Moon
is plotted at selected phases in
the evening sky, and any planets visible are plotted where
they're located in the middle
of the month.
Lower right of the map
is a scale showing the magnitudes (brightnesses) of the
stars. Each map shows stars to
as faint as 4th magnitude -
about as dim as you can see
with your eyes through typical
suburban light pollution.

Facing NW
Vega

LYRA

Into the Night

18 h
North
ern
Cros
s

ng

21h

t

DE

LP

HI

NU

S

Fa

CYGN
US

ci

ng

15

Fa

ci

h

D

Deneb

15

R

A

+6

C

O

0°

¡

M

N

th

W
es

or

S

RIU

S

D

+

TA

AQ

G

b

P

E

L

_

S
EU
PH
CE

A

UA

S

U

LACER
`

C ir cl

et

t
a e
e ar
r
G u
q
S

R

Facing SW

M33

E

A

a

0h

0°

IG

CE
TU
S

RR
O
O

TT

A

¡

0°

R

IN

_

37

M

_
or
st

M

N

x

I

llu

Po

A

Mir

Algol

U

M

E

Ca

G

38 6
M M3

U

+8

`

D

ris
la

IA

a
M
GULU

M34

`

A

N
TRIA
AR
IE
S

a

Po

PE

+6

_

S
PERSEU

la

el

ap

C

`

on
Mon 20
Ja

`

A
D
E
M_

b

le
ub r
Doluste
C

O

M

IO

a

A
LIS

rs

Ma

N
PISCES A

SS

_

31

LO
P
RD
A

LYNX

C

I C
P T
L I
E C

_

_

CA
`

`

A
S R
R °O
U +I 8N0
M

ME

1

+2

des

0°

_

e
tl r
it pe

2

M8

CA

M8

_

`

URS
A
M

Pleia

on
Mon 24
Ja

`

n
oo 7
M an 1
J

Q

ip

_

B
Dip ig
pe
r

th
ni
Ze

35

`

C

0°

Ald

c

E

US
ran
eba A U R
T

R
h

a

4

M4

_

Y

Pr

Betelgeus

e

ORION
M42

`

yo

R

n

A

ci
ng

M

N

U

S 20°
-

g
-4

_

st

R

A

`

oc

D

Fa
Ea

E

Rigel

ID

ON
OC
ER
OS

0°

h

3
`

Sirius

`

_

CANI
S

S
PU
LE

MAJO
R

Facing SE

h

6

th

H

9h

C
M AN
IN I
O S
R

Bellatrix
a

ou

8

Let's try finding our way with the map labeled "January"
(page 13). Turn it around and hold it so its southeast
horizon (labeled "Facing SE") is at the bottom. Nearly
halfway from there to the center of the map you'll find
the constellation Orion - with bright orange Betelgeuse in one shoulder, bluish-white Rigel marking
his upraised foot, and the three-star Belt of Orion
in between. Go outside at one of the times listed
in the top-left corner, face southeast, and look
about halfway up the sky. There's Orion!
The maps (and smaller sky scenes) are
drawn for a skywatcher near latitude 40° north
(for example, New York or Denver). If you're far
south of 40°N, stars in the southern part of the
sky will appear higher than on the maps, and
stars in the north will be lower. If you're far north
of 40°N, the reverse will be true.

Fa

ci

ng

S

■ CHECK OUT OUR
INTERACTIVE STAR MAP:
skyandtelescope.org/interactive-sky-chart

Three Tips
Look for the
bright stars
and patterns ﬁ rst;
the faint ones are
often hard to see.

1

Constellations
look a lot bigger in the sky than
here on paper!

2

To see the
faintest stars
shown, avoid
streetlights and
nights lit by a gibbous or full Moon.

3

Greek Letters
on Star Maps
In each constellation, many stars
are named with
lowercase Greek
letters. The
brightest star is
usually Alpha, the
ﬁrst letter in the
Greek alphabet.

α
β
γ
δ
ε
ζ
η
θ
ι
κ
λ
μ
ν
ξ
ο
π
ρ
σ
τ
υ
ϕ
χ
ψ
ω

Alpha
Beta
Gamma
Delta
Epsilon
Zeta
Eta
Theta
Iota
Kappa
Lambda
Mu
Nu
Xi
Omicron
Pi
Rho
Sigma
Tau
Upsilon
Phi
Chi
Psi
Omega

SK Y WATCH 2021

9
http://www.skyandtelescope.org/interative-sky-chart
Skywatch - 2021

Table of Contents for the Digital Edition of Skywatch - 2021
