Page 122 - BBC Sky at Night Beginners Guide to Astronomy - 2017 UK

WHAT TO SEE

The Andromeda Galaxy is
similar in form to the Milky
Way, but is thought to hold
over twice as many stars

SEE THE

ANDROMEDA

GALAXY

THE SPIRAL GALAXY THAT’S AS FAR AS YOU CAN
SEE IN THE UNIVERSE WITH YOUR EYES ALONE

On so many levels, the Andromeda Galaxy is aids. Some claim that M33, the Triangulum
a marvel. Don’t be fooled by its deceptively Galaxy, can be seen with the eyes alone, but at WHAT WILL
ordinary designation of ‘M31’, given to it mag. +6.2 it’s so ghostly it’s almost not there. M31 LOOK LIKE
by Charles Messier in his 1781 catalogue of Secondly, the distance to the Andromeda
astronomical objects. The more you delve, the Galaxy defi es understanding. In Earth units Under dark, Moon-
free skies, your
more fascinating Andromeda becomes. it’s a staggering 23 billion billion km away.
unaided eye should
Autumn is the best time of year to see the Using more standard large-scale space units,
be able to fi nd the
Andromeda Galaxy: it’s at its highest in the south it’s around 2.5 million lightyears away. In other Andromeda Galaxy as
at about 8pm. As soon as it gets dark, you can be words, you’re looking at the galaxy as it was 2.5 a faint misty patch a
sure that M31 will already be pretty high. To your million years ago. When you consider that most short distance from the
naked eye it will look like a fuzzy patch. From of the stars we see are just tens or hundreds of band of the Milky Way.
urban locations, the galaxy is equally visible in lightyears away, the distance to the Andromeda The ancient Persians
called it a ‘little cloud’.
binoculars, even if you have a fair amount of light Galaxy becomes phenomenal. This is about the
pollution. But dark, Moonless skies will give you farthest thing in the Universe that you can see
Using binoculars,
the best views. using just your eyes. you’ll fi nd the
Knowing a bit about this fuzzy patch of stars Another amazing aspect of the galaxy only galaxy with little or
really starts to bring it to life. Firstly, it’s the only becomes apparent when you take a photograph no diffi culty. It will be
ROB GENDLER/WWW.ROBGENDLERASTROPICS.COM, CHART BY PETE LAWRENCE, WILL GATER
major galaxy that you can see without any optical of it: its enormous extent in the sky, spanning oval in appearance
– although you won’t
then width of six full Moons
be able to make out
side-by-side.
any of the individual
With bigger telescopes, stars within it.
you’ll see a galaxy with spiral
arms that’s similar to the The Andromeda
Milky Way. The Andromeda Galaxy looks great
Galaxy and our own are the through smaller scopes
of, say, 4 inches nches
two most massive systems
in diameter. r.
in a Local Group of around The galaxy y
30 galaxies. But while our appears as s
Galaxy has up to 400 billion a larger,
stars, Andromeda is thought elongated
oval shape
to contain a trillion. With
with a core e
so many more stars, it could that shows
mean that there’s more up as a slightly ghtly
chance of life existing over brighter area – like
Find the Andromeda Galaxy there, in our similar but in this picture.
high in the sky in November
larger galactic sibling.
122 skyatnightmagazine.com 2012