April - Bristol Astronomical Society

Society News
Last month we had a couple of visits to the observatory, on March 7th the Sky at
Night magazine used the site the test a couple of Skywatcher telescopes. The
night was superb for observing (except for the cold) and a number of members
turned up for a evening of observation.
One of these telescopes had a computerised GoTo system while the other had to
be moved manually to locate objects. The idea was to see which set up the best
for locating a number of objects scattered across the sky. After finding that most
of the objects on their list were a bit too faint, a new list was put together and the
test re-started. The GoTo telescope was very accurate and the object being observed was always near the centre of the field of view, however it took a while for
it to slew around the sky, where as the manual telescope could slew to the opposite side of the sky almost instantaneously. I’m not sure what the outcome of the
test was, we will have to wait until the results are published in a future edition of
the magazine.
Bristol Astronomical Society Information Leaflet
April 2010
All times are BST (UT +1hr) unless otherwise stated
Our other visitors were from the 2nd Portishead Scouts group, the weather reports
for the evening were not very good, but as the first date was cancelled due to the
weather, we decided to chance it any way. When we arrived the sky started to
clear and except for a short period the entire sky was almost cloud free. We
showed them Mars (which is not too impressive at the moment), M42 and finally
Saturn. We also took them outside to point out some of the constellations.
The evening was rounded by showing a couple of members how the telescope
worked so they could become key holders.
Programme of Events for April 2010
All meetings are held at Bristol Grammar School.
2nd
Apr
Good Friday - No Meeting
9th
Apr
Herschel: seeing the stolen starlight - Haley Gomez
16th Apr
Club Night - Edie Carpenter
23rd Apr
To See the Beginning of Time - Andrew Lound
30th Apr
Club Night - Tricia Brown
Don’t forget to check out the BAS website where you can get all the latest info
about the society. http://www.bristolastrosoc.org.uk/
Interacting galaxies NNGC 4938 and NGC 4039
Bristol Astronomical Society are a Registered Charity, No. 299649
24
1
The The
Sun &
Moon
Sun
Date
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Sun and Moon Rise and Set times for 2010
Sun
Moon
Rise
Set
Rise
06:46
1843
23:35
06:44
1845
06:42
1847
00:49
06:39
1848
01:52
06:37
1850
02:42
06:35
1852
03:20
06:33
1853
03:49
06:31
1855
04:11
06:28
1857
04:29
06:26
1858
04:45
06:24
20:00
04:59
06:22
20:02
05:13
06:20
20:03
05:28
06:17
06:15
06:13
06:11
06:09
06:07
06:05
06:03
06:00
05:58
05:56
05:54
05:52
05:50
05:49
05:47
05:45
20:05
20:07
20:08
20:10
20:12
20:13
20:15
20:17
20:18
20:20
20:22
20:23
20:25
20:27
20:28
20:30
20:32
2
05:45
06:05
06:31
07:05
07:51
08:50
10:02
11:22
12:45
14:09
15:33
16:57
18:21
19:45
21:08
22:26
23:35
Constellation of the Month
Set
07:13
07:44
08:24
09:15
10:14
11:20
12:28
13:37
14:46
15:54
17:03
18:12
18:23
20:37
21:52
23:06
00:16
01:17
02:05
02:43
03:11
03:34
03:54
04:11
04:29
04:49
05:12
05:41
06:17
Sextans
Abbreviation: Sex
Genitive: Sextantis
Sextans, the third of our constellations was first introduced by Johannes Hevelius
in 1687 as ‘Sextans Uraniae’ to commemorate the main instrument he used to
measured star positions, which was destroyed in a fire at his observatory in 1679.
Objects in Sextans
NGC 3115, The Spindle Galaxy is an almost edge on Lenticular Galaxy which
lies around 5 degrees south of alpha Sextantis. The galaxy covers an area of 8 x 3
arcminutes and has an overall magnitude of +8.9. This is a target for medium to
large instruments.
Stars in Sextans
Sextans is a faint constellation, it’s brightest star, alpha (α) Sextantis is a white Aclass giant which shines at magnitude +4.49. The star lies around 12 degrees
south of Regulus (alpha Leonis) and just a ¼ degree south of the celestial equator.
Alpha along with beta (β) and delta (δ) form a right-angled triangle with alpha at
the tip. Beta Sextantis
lies at the right-angle
of the triangle, it is a B
-class (B6) blue-white
dwarf. Beta is an Alpha2 Canum Venaticorum type variable
with a brightness range
between +5.0 to +5.1.
Delta is a magnitude
+5.21 B-class (B9)
blue-white dwarf.
Gamma (γ) Sextantis is
a multiple star which
lies in the south of the
constellation.
Objects in
Object
Spindle Galaxy
NGC
Type
3115 Lenticular Galaxy
23
Mag
RA
Dec
+8.9
10h 05.2m
-07° 43'
Constellation of the Month
The Sun & Moon
star with a magnitude +9.6 companion lying 5.3 arcseconds away. This makes
this double a good target for small telescopes. Delta (δ) is a K-class (K0) orange
giant.
The Sun
There seems to have been be an increase in an
activity on the Sun in the last few months with
plenty of active regions appearing on the disc.
There have also been a number of Coronal Mass
Ejections (CME’s) recently. The image on the
right was taken by the STEREO (Ahead) spacecraft on 28th Feb 2010. This is one of the largest
and brightest CME’s in the last few years.
The Moon
14th
13:19
Object
NGC
3511
3513
3887
Gamma Crt
Objects in Crater
Type
Mag
Spiral Galaxy
+11.5
Spiral Galaxy
+11.9
Barred Spiral
+11.3
Galaxy
Double Star
+4.08 & +9.2
22
RA
11h 03.4m
11h 03.7m
Dec
-35° 05'
-23° 14'
11h 47.1m
-16° 51'
11h 24.9m
-17° 41'
21th
19:20
28th
13:19
6th
10:37
This month we look at Archimedes; the largest crater on the Mare
Imbrium (Sea of Showers). This large crater lies just west of the lunar meridian,
Lat 29.7o N, Lon 4.0o W. Archimedes has a diameter of 82 km (50 miles), the floor
of the crater is filled with lava and is relatively smooth and flat, unlike the majority
of lunar craters, Archimedes does not
have a central mountain peak. Within
the crater there are a number of small
Montes Caucasus.
craterlets. The walls of Archimedes
rise to over 2100m (6500 ft), the outer
slopes are steep and to the south lead
Aristillus
down to Archimedes Montes. There
Autolycus
are several long rille's running from
Archimedes
the southern rim of the crater and
heading in a south-easterly direction.
Running in a large arc to the east of
Archimedes and forming the western
boundary of the Mare Imbrium are two
Montes Apenninus
mountain ranges, Montes Apenninus
and Montes Caucasus.
There are some exceptional peaks
Eratosthenes
within these ranges including Mons
3
The Sun & Moon
Constellation of the Month
Ampère, Mons Huygens, Mons Bradley, Mons Hadley.
To the northeast of Archimedes you will find Aristillus, Lat 33.9° N, Lon 1.2° E.
Aristillus has a diameter of 55km (33 miles). The floor of the crater is flat with a
triple central peak rising to over 900m. Aristillus has very steep sides with high
terraced walls. Completing a trio of craters is Autolycus a slightly smaller version
of Aristillus. Autolycus has a diameter of 39 km (24 miles), the floor is flat with a
central peak. The crater walls are high and terraced, the outer slopes are steep and
rugged and there is a small craterlet, Autolycus A on the eastern slopes.
The best time to view the all these features are around first and last quarter.
The crater Archimedes was given it’s name by Giovanni Battista Riccioli in
honour of the 3rd century BC Greek mathematician. Archimedes is probably best
known for the water lifting screw that bears his name. He was also involved in the
calculation of Pi and is credited with the invention of the lever and pulley.
.
Objects in Corvus
Object
NGC
Type
Interacting
4038
Galaxies
4039
4361 Planetary Nebula
Delta Corvi
Double Star
Mag
RA
Dec
+10.5
+10.3
+
12h 01.9m
-18° 52'
12h 24.5m
-18° 48'
+3.0 & +9.2
12h 29.9m
-16° 31'
Crater
Abbreviation: Crt
Genitive: Crateris
Mythology
Like Corvus, Crater is an ancient constellation, it is linked to the story of Corvus
and Apollo. It was put into the sky just out of reach of the Corvus as a punishment
for the bird failing to fetch water for Apollo, the cup is normally represented as a
large double-handed chalice of the type known in Greece as a Krater.
Objects in Crater
There are no Messier objects in Crater, however there are a number of galaxies
from the NGC catalogue. NGC 3887 and NGC 3511 and NGC 3513 are the
among the easier targets for amateur observers. NGC 3887 is an 11th
magnitude barred spiral which lies within the bowl of Crater, to the
northwest of zeta (ζ) Crateris. NGC 3511 and NGC
3513 can be found in the southwest corner of the
constellation. These two 12th magnitude galaxies lie just 11
arcminutes apart and can be seen in the same field of view of in a
large telescope.
Stars in Crater
The main body of Crater is almost a mirror image of Corvus, a quadrilateral of
four stars, alpha, beta, gamma and delta. The bowl of the ’Cup’ is formed by eta
and zeta on the eastern side and epsilon and theta on the western side.
Alpha (α) Crateris is the only star in the constellation which has been given a
proper name, Alkes; from the Arabic meaning ‘the wine cup’. Alkes at magnitude
+4.07 is the second brightest star in crater, delta is brighter at magnitude +3.56.
The star is an orange K-class (K0) giant. Around 5 degrees to the southeast you
will find beta (β) Crateris, a magnitude +4.48 A-Class (A2) white giant. Gamma
(γ) Crateris is a double star, the primary is a magnitude 4.08 A-class (A5) white
4
21
The Planets
Constellation of the Month
Stars in Corvus
Alpha (α) Corvi marks the beak of the crow, it is a F-class (F0) yellow dwarf star.
Despite its alpha designation it only 5th in brightness at magnitude +4.00. The
star’s proper name, Alchiba means ‘tent’ in Arabic and is thought to refer to the
four stars that make up the main body of the crow.
Beta (β) Corvi has the proper name Kraz, this is a modern name and no one is
sure of its meaning. The star is a magnitude +2.65 G-class (G5) yellow/white giant. Beta marks the south-eastern corner of the ‘box’.
The south-western corner is marked by epsilon (ε) Corvi a magnitude +3.00 Kclass (K2.5) giant. The star’s proper name Minkar is a shortened version of Al
Minkar al Ghurab, which means the ‘the Raven's Beak’ and should really apply to
alpha.
In the north-western corner you will find gamma (γ) Corvi, it has a very apt name,
Giennah meaning ‘the Raven’s wing’. Gamma is a B-class (B8) blue-white giant
which shines at magnitude +2.59. Delta (δ) Corvi at the north-eastern corner is a
nice double star, the primary is a white B-class star shining at magnitude +2.95
with a +9.2 K-class companion. The separation is 24 arcseconds making this a
good target for small instruments. The contrast between the two stars have led to
some interesting reports on their colours from ‘white and bluish’ to ‘yellowish
and pale lilac’ and ‘pale yellow and purple’, take a look and see what colours they
appear to your eyes.
Mercury
Date
RA
Dec
Mag Phase Dia
01
01h 41m +12° 06' -0.9 69% 6.2"
15
02h 34m +18° 21' +1.3 20% 9.2"
30
02h 18m +14° 20' +5.4 01% 12.0"
Rise
07:03
06:24
05:33
Transit
14:12
14:09
12:52
Set
21:23
21:53
20:10
Mercury reaches greatest eastern elongation on the 8th when it will 19 degrees
from the Sun. The innermost planet will be visible in the western sky in the early
evening for the first half of the month. This is the best evening apparition of the
year for the UK so take advantage and see if you can spot this elusive little planet.
Venus
Date
01
15
30
RA
Dec
Mag Phase
01h 54m +11° 12' -3.9 94%
03h 01m +17° 13' -3.9 92%
04h 16m +22° 05' -3.9 89%
Dia
11"
11"
11"
Rise
07:21
06:58
06:42
Transit
14:25
14:36
14:52
Set
21:29
22:16
23:04
Venus is visible in the western sky in the early evening, during the first half of
the month Venus in the same part of the sky as Mercury and should help you to
locate the much fainter inner planet. On the 16th Venus and Mercury and joined
by the 2 day old waxing crescent Moon. At a magnitude –3.9 the planet will be
obvious to even the most casual of observers. Through a telescope Venus will
show a gibbous phase ranging from 94% illuminated at the start of the month to
89% at the end of the month.
The chart above shows the position of Mercury, Venus and the Moon on the 16th
20
5
The Planets
Mars
Date
01/02
15/16
29/30
RA
Dec
Mag Phase Dia
08h 23m +22° 18' +0.2 91% 9.2"
08h 39m +20° 57' +0.5 90% 8.2"
08h 59m +19° 13' +0.7 90% 7.3"
Constellation of the Month
Rise
12:40
12:11
11:48
Transit
20:51
20:12
19:37
Set
05:01
04:13
03:27
Mars can be found moving quickly through the constellation of Cancer, on the
17th it lies close to M44. During the month the planet fades by half a magnitude
from +0.2 to +0.7 as its apparent diameter decreases from 9.2 to 7.3 arcseconds.
This month as a follow on to last month’s featured constellation we look at three
small constellations that ride on the back of Hydra, Corvus (the Crow), Crater
(the Cup) and Sextans (the Sextant). Corvus and Crater are classical constellations
dating back to the time of the ancient Greeks while Sextans was introduced in the
17th century by Johann Hevelius. All three are relatively faint with no stars
brighter than 3rd magnitude.
Corvus
Abbreviation: Crv
Genitive: Corvi
Jupiter
Date
01
15
30
RA
Dec
23h 14m -05° 57'
23h 26m -04° 45'
23h 37m -03° 32'
Mag Phase
-2.0 100%
-2.0 100%
-2.1 99%
Dia
34"
34"
35"
Rise
06:11
05:22
04:28
Transit
11:44
11:01
10:13
Set
17:17
16:40
15:58
Jupiter may be glimpsed at the end of the month very low in the eastern sky just
before dawn towards the end of the month. The giant planet currently lies in the
constellation of Aquarius close to the boarder with Pisces.
Saturn
Date
01/02
15/16
29/30
RA
Dec
Mag
12h 05m +02° 14' +0.6
12h 01m +02° 37' +0.7
11h 58m +02° 55' +0.8
Phase
100%
100%
100%
Dia
20"
19"
19"
Rise
18:18
17:18
16:18
Transit
00:32
23:34
22:36
Set
06:47
05:50
04:53
Saturn rises in the early evening and is visible for most of the night. The ringed
planet can be found in the constellation of Virgo moving in a retrograde direction.
The famous ring close up during the month and will be tilted at an angle of just 2
degrees by the
end of April.
This chart shows
the position of
Mars and Saturn
on the evening
of the 16th.
6
Mythology
Corvus was sent by the god Apollo to fetch a cup of water, however on the way
saw a fig tree and instead of returning straight away with the water it decided to
wait for the fruit to ripen. When Corvus eventually returned it blamed the delay
on a serpent (Hydra) that had attacked it. Apollo knew that Corvus was lying, so
as punishment he banished Corvus to the night sky, just beyond it’s reach lies a
cup of water (Crater).
Of the three constellation, Corvus is the most clearly defined, four stars beta (β),
delta (δ), gamma (γ) and epsilon (ε) form a squashed ‘box’ shape.
Objects in Corvus
There are no Messier object in Corvus however it does have one outstanding deep
-sky object, an interacting pair of galaxies (NGC 4038 & NGC 4039) known as
the Antennae or Ring-Tail Galaxy. At magnitude +10 and low in
the sky this is not an easy object from the UK but on a very good
night it is worth a try with a large telescope.
NGC 4361 is a planetary nebula around 45 arcseconds in diameter. The central star is around 13th magnitude. The nebula lies
within the quadrilateral of stars about one third of the way from
delta to epsilon.
One of the things Astronomers like doing is forming shapes from
groups of stars, these shapes are known as Asterisms. In Corvus you will find an
asterism known as the ‘Stargate Cluster’, it lies approximately midway between
delta (δ) Corvi and Chi (χ) Virginis. The asterism got its name
because it reminded its discoverer of the Stargate used by Buck
Rogers to enter hyperspace. You will need large binoculars or a
small telescope to see this asterism.
19
The Sky this Month
Uranus
The Sky looking East around midnight mid April 2010
Date
01
15
30
RA
Dec
23h 51m -01° 44'
23h 53m -01° 26'
23h 56m -01° 08'
Mag
+5.9
+5.9
+5.9
Phase Dia
100% 3.3"
100% 3.4"
100% 3.4"
Rise
06:26
05:33
04:34
Transit
12:20
11:28
10:32
Set
18:15
17:23
16:29
Uranus lies in the constellation of Pisces to the south of lambda (λ) Piscium. It
rises shortly after Jupiter and will be difficult to locate in the morning twilight.
Neptune
Date
01
15
30
RA
Dec
21h 59m -12° 42'
22h 01m -12° 35'
22h 02m -12° 29'
Mag
+7.9
+7.9
+7.9
Phase Dia
100% 2.2"
100% 2.2"
100% 2.3"
Rise
05:33
04:39
03:41
Transit
10:29
09:36
08:38
Set
15:25
14:33
13:35
Neptune currently lies on the eastern edge of Aquarius close to the boarder with
Capricornus. The outermost planet rises around 3/4 of an hour before Jupiter.
Neptune will be difficult to spot in the dawn sky.
Pallas
Date
01
15
30
RA
Dec
21h 59m -12° 42'
22h 01m -12° 35'
22h 02m -12° 29'
Mag
+7.9
+7.9
+7.9
Phase Dia
100% 2.2"
100% 2.2"
100% 2.3"
Rise
05:33
04:39
03:41
Transit
10:29
09:36
08:38
Set
15:25
14:33
13:35
The Minor Planet 2Pallas (the second to be discovered) reaches opposition in the
constellation of Serpens Caput
on April 30th. Pallas will be
magnitude +8.7 at the time of
opposition so should be visible
in binoculars or small telescopes.
You will find Pallas just below
alpha and beta Coronae Borealis
on the 30th. Pallas starts the
month within the triangle of stars
that form the head of the serpent
and moves in the direction of
Corona Borealis.
18
7
Now that we have moved to British Summer Time, spring is well and truly here.
The bright winter constellations set early in the evening and are replaced in the
southern sky by the not so obvious spring constellations.
The southern part of the sky is dominated by the constellation of Leo, one of the
few constellations that resembles the object it is supposed to represent, in the case
of Leo, a Lion. One of the many myths connected to Leo is that it represents the
Nemean Lion which was killed by Hercules as the first of his ‘12 Labours’.
Regulus; alpha (α) Leonis, is the constellation’s brightest star, it marks one of the
front paws of the great lion. Regulus also marks the bottom of asterism known as
‘the Sickle’ that represents the head and mane of the lion. The sickle is formed by
the stars alpha (α), eta (η), gamma (γ), zeta (ζ), mu (μ) and epsilon (ε). Gamma
Leonis is an excellent double star for small telescopes, the primary is a magnitude
+2.2 K-class yellow-orange giant, it’s companion is a magnitude +2.5 yellow Gclass star. The pair is separated by 4.4 arcseconds. The rear of Leo’s body is
formed by the stars theta (θ), delta (δ) and beta (β). Below the Lions body there are
a number of galaxies including M65, M66, and NGC 3628, known as the ‘Leo
Triplet’ and M95, M96 and M105.
The Sky looking North around midnight mid April 2010
The Sky this Month
To the west of Leo you will find the faint constellation of Cancer. If it were not
for the fact that Cancer is one of the Zodiacal constellations, it would probably be
8
17
The Sky this Month
The Sky looking West around midnight mid April 2010
ignored. It does however have one other redeeming feature, it is
home to one of the loveliest open clusters in the sky, Praesepe,
now more commonly known as the Beehive Cluster or M44. This
lovely group of stars is just visible to the naked-eye even from
Bristol, and a stunning sight in binoculars
To the southeast of Leo lies the large faint constellation of Virgo. It’s brightest star
Spica lies in the south of the constellation, it is a B-class blue giant. Spica is a beta
Cephei type variable with a range
between +0.92 and +1.04, with a
period of just over 4 days. Other
than Spica, the most distinctive
part of Virgo is the bowl shape at
the western end. Within this bowl
and extending into neighbouring
Coma Berenices is a huge cluster
of galaxies including a number of
Messier objects M49, M58, M59,
M60, M61, M84, M86, M87,
M89, M90 and M104. Many of
these galaxies are visible in amateur telescopes. The chart shows
the central part of the Coma/Virgo
cluster.
Snaking across the south and south-western horizon you will find Hydra (the water
snake); the largest constellation in
the sky. Hydra is relatively a faint
constellation, perched on its back
you will find this months featured
constellations Corvus, Crater and
Sextans.
Lying to the east of Leo and Coma
Berenices lies the Kite shape of
Boötes with the bright orange giant
Arcturus at its base. Further to the
east lies Hercules,
home to two lovely
globular clusters
M13 and M92.
M13 is by far the
16
9
best globular cluster visible in the northern half of the sky.
Lying between Boötes and Hercules is the semi-circular constellation of Corona
Borealis which is home to the prototype of a strange class of variable stars, R
Coronae Borealis. Most types
of variable star brighten from
their normal state, R CrB type
variables fade dramatically.
The star is currently at a deep
minimum, below magnitude
+15, the faintest it’s been for
many years. Keep an eye on R
Coronae and check when it
returns to it’s normal level of
magnitude +6. The chart on
the right shows the position of
R CrB.
The Summer constellations are now becoming visible low in the eastern sky, by
the early hours of the morning the constellation of Lyra will be at a reasonable
height, allowing observation of one of
the sky's show pieces objects M57; the
Ring Nebula. This lovely planetary
nebula can be seen as a small hazy
patch in small instruments, medium to
large telescopes will show the classic
‘Smoke
Ring’
shape of M57.
The Ring Nebula
is quite an easy
object to locate, it
lies between beta
(β) and gamma (γ) Lyrae, at about one
third of the way from beta to gamma.
One of the other highlights of Lyra is
epsilon (ε) Lyrae; the ‘double double’.
What appears to be a single star to the naked-eye, splits into two pairs, Epsilon1
and Epsilon2 when viewed with a telescope. Epsilon1 is the northernmost pair
with components of magnitude +4.7 and +6.2 separated by 2.6 arcseconds. The
two stars are physically linked, orbiting each other approximately every 1200
years. Epsilon2 consists of +5.1 and +5.5 magnitude stars separated by 2.3
10
The Sky looking South around midnight mid April 2010
The Sky this Month
15
The Sky looking Overhead around midnight mid April 2010
The Sky this Month
arcseconds. This pair are also physically linked, orbiting each other every 585
years.
Low in the north-eastern sky you will find one of the signposts of the summer sky,
the cruciform shape of Cygnus. Deneb; alpha Cygni; is one of the stars that forms
the asterism of the ‘Summer Triangle’ the other two are Vega; alpha Lyrae and
Altair; alpha Aquilae. Albireo; beta (β) Cygni, the star that marks the swan’s beak
at the southern end of the ‘cross’ is one of the loveliest double stars in the northern
sky. The two components have contrasting colours of golden yellow and blue/
green. The brighter of the two is a magnitude +3.3 yellow giant, it’s companion is
a blue dwarf shining at magnitude +5.3.
Over in the western sky, Gemini, will remain visible until the early hours of the
morning. Castor (α Geminorum) is another nice double star for small instruments.
The components are both A-class stars, magnitudes +1.93 and +2.97 separated by
6 arcseconds. At the feet of the twins lies the open cluster M35.
Lying to the northwest of Gemini you will find Auriga. There are three lovely
open clusters in Auriga, M36, M37 and M38 all visible in binoculars and small
telescopes.
In the northern sky, Polaris lies about midway between the horizon and the zenith.
14
11
The Sky This Month
Polaris lies under half a degree from the north celestial
pole, and from the Earth the whole of the northern sky
seems to rotate about this point. Below Polaris you will
find the crooked house shape of Cepheus and the W
shaped Cassiopeia. The central star in the ‘W’, gamma
(γ) Cassiopeiae is the prototype of a class of eruptive
type variables. Gamma is a naked eye variable which
varies irregularly in brightness between +2.20 and
+3.40.
Overhead you will find the familiar pattern of seven
stars known as the ‘Plough’. This asterism which is part
of the constellation of Ursa Major is a useful guide to
help you locate a number of other constellations. If you
follow the curve of the handle to the south it will point
the way to Arcturus; the brightest star Boötes and also
the brightest star in the northern hemisphere of the sky.
Continuing the arc further to the south will bring you to
the bright star Spica; the brightest star in Virgo. The
two end stars in the bowl of the plough, Dubhe (α Ursa
Majoris) and Merak (β Ursa Majoris) are known as the
pointers as they point to one of the most famous stars in
the sky, Polaris, the pole star. Following a line from the
other two stars in the bowl to the south will bring you to
Regulus in the constellation of Leo.
There are a number of deep-sky objects in Ursa Major
including 7 that made it into Messier’s catalogue, M40,
M81, M82, M97, M101, M108 and M109.
01 Apr 01:00
16 Apr 00:00
30 Apr 23:00
Chart Produced by
Chris Peat
http://www.heavens-above.coom
12
13