Page 52 - BBC Sky at Night - September 2017 UK

52 SEPTEMBER THE SKY GUIDE

The three top
sights to observe
THE BIG THREE or image this month

DON’T MISS 29 Aug

Venus and a d 30 Aug

M44 Asellus Borealis M44 31 Aug e Venus

1 Sep
WHEN: 1-3 September; also look for
the planet on 18-21 September for
its meeting with Regulus
CANCER
Venus makes a close pass along 2 Sep
the southern edge of the Beehive b
Asellus Australis
Cluster, M44 in Cancer, at the
start of the month. There’s something quite
compelling about seeing Solar System 3 Sep
objects close to deep-sky ones. Comets
against distant galaxies, or planets
passing through or near familiar clusters
4 Sep
create a wonderful opportunity to
contemplate the three-dimensional
nature of our skies. Þ The location of Venus at 04:30 BST (03:30 UT) as it passes the Beehive Cluster at the end of
The Beehive Cluster is a familiar August and in the first few days of September. They will be low in the east-northeast at this time
object in the spring, but during autumn
additional effort is required to view it. From the UK this makes the planet
It rises in the northeast around appear directly below the cluster. By
03:30 BST (02:30 UT) as seen from the the 3rd the main event is all but over,
centre of the UK and takes a while to Venus now appearing 2º from M44
climb out of the thick, often hazy and 0.5º east of mag. +3.9 Asellus
layer of atmosphere close to the Australis (Delta (b) Cancri).
horizon. However, brilliant If you get clear skies at the
Venus will fare better. start of the month, try to
The cluster is ranked at mag. catch the pair just after they
+4.0, although it’s harder to rise and keep watch over the
spot with the naked eye than next hour until the brightening
this figure suggests. Typically, twilight washes the cluster’s
under reasonably dark stars from view.
conditions, M44 can be seen as a Later in the month Venus
hazy smudge with direct vision. passes very close to mag. +1.4
It has an appreciable apparent size, Regulus (Alpha (_) Leonis). On
measuring approximately 1.5º M44 18 September the planet can be
across. It is best seen through a pair of seen 2.3º northwest of the star.
binoculars, which do both its size justice A lovely 4%-lit waning crescent Moon
and help to bring out the myriad stars hangs immediately below Regulus on
that appear to swarm around the core this date. Venus appears to close in on
like bees around their hive. Þ Located near the ecliptic, M44 is no the star over the next couple of mornings,
On 1 September Venus sits 1.25º stranger to Solar System visitors; here sitting 0.5º north-northeast of it on the
it is with an overexposed Moon
PETE LAWRENCE X 4 this places Venus below and right of field to contain the cluster and planet an opportunity to try and spot Regulus
morning of 20 September. This presents
southwest of the cluster. From the UK
during daylight using a telescope. Lock
the cluster’s core. Again, binoculars
at the same time.
are an ideal way of getting a good view,
onto Venus as the Sun rises and see if you
On 2 September, Venus appears 1.5º
east of south of the cluster’s centre.
a typical pair having a sufficiently large
can spot the star nearby.
skyatnightmagazine.com 2017