Download VISIT TO NORMAN LOCKYER OBSERVATORY IN SIDMOUTH

BRIDGEND ASTRONOMICAL SOCIETY
VISIT TO NORMAN LOCKYER OBSERVATORY IN SIDMOUTH AUGUST 8th 2015
Jon Laver is organising a Society visit to the famous Norman Lockyer
Observatory in Sidmouth, Devon where we will be given a talk and a
tour of the observatory and telescopes. The South West Astronomy Fair
is being held at the NLO on that date and there will be lots of special
events going on. Speakers include Allan Chapman and Richard Fleet.
More information at: http://www.southwestastrofair.com/
JUN 12 AGM
SEPT 11 Solar Eclipses by Margaret Collins of Swansea Astronomical Society
OCT 9 TBA by Dr Bob Owens of National Museum of Wales
NOV 13 The Hale Telescope by Dr Rhodri Evans of Cardiff University
DEC 11 Transient Astronomy with Gravitational Waves by Dr Stephen Fairhurst of Cardiff
University
2016
JAN 8 A 3D Tour of our Solar System and Beyond by Dr Emma Wride of the University of
South Wales
FEB 12 Extra Dimensions and the Brane World Scenario by Dr Ivonne Zavala of Swansea
University
MAR 11 Studying the Atmospheres of Extra-Solar Planets by Professor Matt Griffin of
Cardiff University
APRIL 8 Microquasars, Jets and Neutron Stars By Dr Fraser Lewis of the University of South
Wales
MAY 13 The Gaia Satellite by Dr Sarah Roberts of the University of South Wales
JUNE 10 AGM
The Night Sky June 2015
Compiled by Ian Morison
Image of the Month
Hubble Image of the Galaxy NGC6240
Image:AURA/STScI,A.Evans(U.Virginia/NRAO/Stony Brook U.) ESA, NASA
NGC 6240 lies at a distance of 400 million light years in the constellation Ophiuchus. It is a
nearby example of a galaxy-galaxy collision. The tidal effects of the two galaxies produce tails of
stars, gas and dust amid bursts of star formation. The two supermassive black holes at the
hearts of the merging galaxies will coalesce into one and finally only a single galaxy will
remain. The image spans ~300,000 light years across.
Highlights of the Month
June - still a good month to observe Saturn.
Saturn in the evening Sky
Saturn reached opposition on the 10th of May, so is now due south and highest in the
sky soon after darkness falls.
To find it in the sky, follow the arc of the Plough's handle downwards to first find the
orange star Arcturus and continue down to find the white, first magnitude star, Spica, in
Virgo. Saturn, a little brighter than Spica, lies in Libra down to its lower left and will
appear slightly yellow in colour.
Held steady, binoculars should enable you to see Saturn's brightest moon, Titan, at
magnitude 8.2. A small telescope will show the rings with magnifications of x25 or
more and one of 6-8 inches aperture with a magnification of ~x200 coupled with a night
of good "seeing" (when the atmosphere is calm) will show Saturn and its beautiful ring
system in its full glory.
As Saturn rotates quickly with a day of just 10 and a half hours, its equator bulges
slightly and so it appears a little "squashed". Like Jupiter, it does show belts but their
colours are muted in comparison.
The thing that makes Saturn stand out is, of course, its ring system.
The two
outermost rings, A and B, are separated by a gap called Cassini's Division which should
be visible in a telescope of 4 or more inches aperture if seeing conditions are
good. Lying within the B ring, but far less bright and difficult to spot is the C or Crepe
Ring.
Due to the orientation of Saturn's rotation axis of 27 degrees with respect to the plane of
the solar system, the orientation of the rings as seen by us changes as it orbits the Sun
and twice each orbit they lie edge on to us and so can hardly be seen.
This last
happened in 2009 and they are now opening out, currently at an angle of 24 degrees to
the line of sight. The rings will continue to open out until May 2017 and then narrow
until March 2025 when they will appear edge-on again.
See more of Damian Peach's images: Damian Peaches Website"
Saturn imaged in April 2012 by Damian Peach
June - Find the globular cluster in Hercules and spot the
"Double-double" in Lyra
Use binoculars to find the globular cluster M13 in Hercules and the "Double-double" in Lyra
Image: Stellarium/IM
There are two very nice objects to spot with binoculars in the western sky well after dark
this month. Two thirds of the way up the right hand side of the 4 stars that make up
the "keystone" in the constellation Hercules is M13, the best globular cluster visible in
the northern sky. The 15 minute exposure image on right was taken by the author
using a 127 mm APO refractor and SBIG 8.3 megapixel CCD camera.
Just to the left of the bright star Vega in Lyra is the multiple star system Epsilon Lyrae
often called the double-double.
With binoculars a binary star is seen but, when
observed with a telescope, each of these two stars is revealed to be a double star hence the name!
M13 imaged by Ian Morison in May 2014
Late June: A very good time to spot Noctilucent Clouds!
June: the chance to spot Noctilucent Clouds
Image: Wikipedia Commons
Noctilucent clouds, also known as polar mesospheric clouds, are most commonly seen in
the deep twilight towards the north from our latitude. They are the highest clouds in
the atmosphere at heights of around 80 km or 50 miles. Normally too faint to be seen,
they are visible when illuminated by sunlight from below the northern horizon whilst the
lower parts of the atmosphere are in shadow. They are not fully understood and are
increasing in frequency, brightness and extent; some think that this might be due to
climate change! So on a clear dark night as light is draining from the north western sky
long after sunset take a look towards the north and you might just spot them!
Night of June 15 to 16th when fully dark: The Lyrid Meteor
Shower
The Lyrid Meteor Shower
Image: Stellarium/IM
The June Lyrid meteor shower reaches its peak on the night of the the 15th/16th with a
rate at the zenith of ~8 meteors per hour. This is not many, but the fact that its around
new Moon gives us a good chance to spot one. The radiant is very close to the star
Vega. Many more meteors were seen from the shower in the late 1960's but the peak
hourly rate has dropped off markedly since then. If clear, it’s well worth aiming to see if
the shower still exists.
June 12-13th after sunset: Venus close to the Beehive
Cluster, M44, in Cancer.
Venus close to the Beehive Cluster
Image: Stellarium/IM
After sunset on the nights of the 12th to 13th June, Venus passes close to the Beehive
Cluster, M44, in Cancer. M44 is also called 'Praesepe'.
June 28th after sunset: Saturn close to a waxing gibbous
Moon.
Saturn close to a waxing Moon.
Image: Stellarium/IM
After sunset on the 28th, Saturn will be seen close to an 88% lit waxing gibbous
Moon. As the night progresses, they come closer and are just over one degree apart as
they set at around 02:30 BST the following morning.
June 30th after sunset: A close conjunction of Venus and
Jupiter.
A conjunction of Venus and Jupiter
Image: Stellarium/IM
As Jupiter moves slowly towards Regulus in Leo throughout the month of June, Venus is
moving more quickly across the heavens from Cancer into Leo and, on the 30th of the
month, catches up with Jupiter when they come just 21 arc minutes from each
other. Interestingly, both planets will then have the same angular diameter of 32 arc
seconds, but whilst Jupiter sports an almost fully illuminated disk, that of Venus will be a
thin crescent just 34% illuminated. Low above the horizon, they will dominate the sky
in the west-northwest from around 22:30 BST until they set around an hour later.
June 25th and 26th: The Alpine Valley
Alpine Valley region
An
interesting
valley
on
the
Moon:
The
Alpine
Valley
These are two good nights to observe an interesting feature on the Moon if you have a
small telescope. Close to the limb (on the 6th) is the Appenine mountain chain that
marks the edge of Mare Imbrium. Towards the upper end you should see the cleft
across them called the Alpine valley. It is about 7 miles wide and 79 miles long. As
shown in the image a thin rill runs along its length which is quite a challenge to
observe. Over the next two nights the dark crater Plato and the young crater Copernicus
will come into view. This is a very interesting region of the Moon!
The Alpine valley and the crater Plato
A Messier Object imaged with the Faulkes Telescope:
Messier 27 - The Dumbell Nebula
The
Image:Nik
Faulkes Telescope North.
Dumbell
Nebula
Szymanik
The
Dumbell
Nebula,
imaged
by
Nik
Szymanek.
This image was taken using the Faulkes Telescope North by Nik Szymanek - one of the
UK's leading astro-photograpers.
M27 is a planetary nebula, the result of a "nova"
explosion at the end of the life of a star like our Sun. The core at the centre of the star
collapses under gravity until it is about the size of the Earth when "electron degeneracy
pressure", resulting from the fact that electrons do not like being squashed too close
together, prevents further collapse. This is called a "white dwarf". As the dying ember
of a nuclear fusion reactor, they are exceedingly hot, but will gradually cool over
time. The outer parts of the star are expelled at high speed into space resulting in the
(in this case) spherical nebula surrounding the white dwarf. The field of the view of the
CCD array on the Faulkes Telescope is a little too small to encompass the whole
nebula. Once, with a 16 inch telescope under perfect conditions, I visually observed
M27 and its central part appeared a vivid iridescent green - the only time I have ever
seen colour in a deep sky object!
Learn more about the Faulkes Telescopes and how schools can use them: Faulkes
Telescope"
Observe the International Space Station
The International Space Station and Jules Verne passing behind the Lovell Telescope on April 1st
2008.
Image by Andrew Greenwood
Use the link below to find when the space station will be visible in the next few days. In
general, the space station can be seen either in the hour or so before dawn or the hour
or so after sunset - this is because it is dark and yet the Sun is not too far below the
horizon so that it can light up the space station. As the orbit only just gets up the the
latitude of the UK it will usually be seen to the south, and is only visible for a minute or
so at each sighting. Note that as it is in low-earth orbit the sighting details vary quite
considerably across the UK. The NASA website linked to below gives details for several
cities in the UK. (Across the world too for foreign visitors to this web page.)
Note: I observed the ISS three times recently and was amazed as to how bright it has
become.
Find details of sighting possibilities from your location from: Location Index
See where the space station is now: Current Position
The Moon
The Moon at 3rd Quarter. Image, by Ian Morison, taken with a 150mm MaksutovNewtonian and Canon G7.
Just below the crator Plato seen near the top of the image is the mountain "Mons Piton". It casts
a long shadow across the maria from which one can calculate its height - about 6800ft or 2250m.
`
new moon
first quarter
full moon
last quarter
June 16th
June 24th
June 2nd
June 9th
Some Lunar Images by Ian Morison, Jodrell Bank Observatory: Lunar Images
A World Record Lunar Image
The Planets
Jupiter
Jupiter is now well past its best, but still stands out in the South to South-west at
nightfall Its brightness falls slightly from magnitude -1.9 to -1.8 whilst its angular size
drops from 35 to 32.5 arc seconds. Jupiter starts the month in Cancer but moves into
Leo on the 9th of June in its eastwards progress towards the star Regulus. Our best
views of the planet are now past for this apparition but, with a small telescope one may
will be able to see the equatorial bands in the atmosphere and up to four of the Gallilean
moons as they weave their way around it. Jupiter has a conjunction with Venus on the
30th as described in the highlight above.
above.
Saturn
Saturn , having reached opposition - that is when it be approximately due south at
midnight (UT) or 1 am (BST) - on May 22nd, will be visible in the southeast at nightfall
and will not set until dawn the following morning. It is moving slowly in retrograde
motion in the eastern part of Libra, but close to the the fan of three stars that makes up
the head of Scorpius and is only 3 degrees away from the fine double star Beta
Scorpii. This is a good time to observe Saturn whose globe is ~18 arcs seconds across
and whose rings span some 41 arc seconds across. They make a beautiful sight as are
tilted 24 degrees from the line of sight - almost as open as they can be. It is sad that
Saturn is now in a low part of the ecliptic and will only reach an elevation of 22 degrees
when due south.
I was able to view it through a 16" telescope last month from a
latitude of +29 in the Sahara Desert and it was stunning - perhaps a trip to the southern
hemisphere is called for!
Mercury
Messenger image of Mercury Nasa
Mercury is at inferior conjunction (that is between us and the Sun) on the 30th May and
then climbs slowly into the pre-dawn sky. It reaches greatest elongation west on the
24th June and will then be at magnitude +0.5 and have a phase of 35%. It should then
be visible with binoculars low above the east-northeast horizon as dawn
breaks. Aldebaran, which lies in front of the Hyades cluster, will then lie ~2 degrees
down to its lower right. By the end of June, Mercury is a little brighter (magnitude -0.1)
and be ~6 degrees above the horizon around 45 minutes before sun rise. To be honest,
this is not a good month to observe the moon-like planet.
Mars
A Hubble Space Telescope image of Mars.
Jim Bell et al. AURA / STScI / Nasa
Mars passes behind the Sun (superior conjunction) on June 14th, so is not visible this
month .
Venus
Venus showing some cloud structure
Venus, shining brightly at magnitude -4.4 (increasing to -4.6 during the month)
dominates the western sky after sunset all month.
It starts the month in eastern
Gemini and crosses into Cancer on the 2nd/3rd where it will reach greatest elongation
from the Sun on June 6th and will then lie 45.5 degrees away from the Sun. At the
start of June it will be visible about half an hour after sunset and be ~29 degrees above
the western horizon. Its angular size increases from 22 to 32 arc seconds during the
month. Following greatest elongation, it becomes an increasingly narrow crescent with
its phase decreasing from 53 to 35%. By the end of June, its elevation above the
horizon at sunset will have dropped to 19 degrees and it will set at around 11:35
BST. Venus has close encounters with the open Cluster M44 in Cancer and, having
passed into Leo on the 25th/26th of the month, has a close encounter with Jupiter on
the 30th. Both events are included in the month's highlights.
See highlights above.
The Stars
The late evening June Sky
The June Sky in the south - late evening.
This map shows the constellations seen towards the south at about 11pm BST in mid
June. High overhead towards the north (not shown on the chart) lies Ursa Major. As one
moves southwards one first crosses the constellation Hercules with its magnificent
globular cluster, M13, and then across the large but not prominent constellation
Ophiucus until, low above the southern horizon lie Sagittarius and Scorpio. To the right
of Hercules lie the arc of stars making up Corona Borealis and then Bootes with its bright
star Arcturus. Rising in the east is the beautiful region of the Milky Way containing both
Cygnus and Lyra. Below is Aquilla. The three bright stars Deneb (in Cygnus), Vega (in
Lyra) and Altair (in Aquila) make up the "Summer Triangle".
The constellation Hercules
Hercules
Between the constellation Bootes and the bright star Vega in Lyra lies the constellation
Hercules.The Red Giant star Alpha Herculis or Ras Algethi, its Arabic name, is one of the
largest stars known, with a diameter of around 500 times that of our Sun. In common
with most giant stars it varies its size, changing in brightness as it does so from 3rd to
4th magnitude. Lying along one side of the "keystone" lies one of the wonders of the
skies, the great globular cluster, M13. Just visible to the unaided eye on a dark clear
night, it is easily seen through binoculars as a small ball of cotton wool about 1/3 the
diameter of the full Moon. The brightness increases towards the centre where the
concentration of stars is greatest. It is a most beautiful sight in a small telescope. It
contains around 300,000 stars in a region of space 100 light years across, and is the
brightest globular cluster that can be seen in the northern hemisphere.
The Globular Cluster M13 in Hercules. Image by Yuugi Kitahara
The constellation Virgo
Virgo
Virgo, in the south-east after sunset this month, is not one of the most prominent
constellations, containing only one bright star, Spica, but is one of the largest and is very
rewarding for those with "rich field" telescopes capable of seeing the many galaxies that
lie within its boundaries. Spica is, in fact, an exceedingly close double star with the two B
type stars orbiting each other every 4 days. Their total luminosity is 2000 times that of
our Sun. In the upper right hand quadrant of Virgo lies the centre of the Virgo Cluster of
galaxies. There are 13 galaxies in the Messier catalogue in this region, all of which can
be seen with a small telescope. The brightest is the giant elliptical galaxy, M87, with a
jet extending from its centre where there is almost certainly a massive black hole into
which dust and gas are falling. This releases great amounts of energy which powers
particles to reach speeds close to the speed of light forming the jet we see. M87 is also
called VIRGO A as it is a very strong radio source.
The Giant Elliptical Galaxy M87 HST image showing the jet
Below Porrima and to the right of Spica lies M104, an 8th magnitude spiral galaxy about
30 million light years away from us. Its spiral arms are edge on to us so in a small
telescope it appears as an elliptical galaxy. It is also known as the Sombrero Galaxy as it
looks like a wide brimmed hat in long exposure photographs.
M104 - The Sombrero Galaxy
The constellations Lyra and Cygnus
Lyra and Cygnus
This month the constellations Lyra and Cygnus are rising in the East as darkness falls
with their bright stars Vega, in Lyra, and Deneb, in Cygnus, making up the "summer
triangle" of bright stars with Altair in the constellation Aquila below. (see sky chart
above)
Lyra
Lyra is dominated by its brightest star Vega, the fifth brightest star in the sky. It is a
blue-white star having a magnitude of 0.03, and lies 26 light years away. It weighs three
times more than the Sun and is about 50 times brighter. It is thus burning up its nuclear
fuel at a greater rate than the Sun and so will shine for a correspondingly shorter time.
Vega is much younger than the Sun, perhaps only a few hundred million years old, and
is surrounded by a cold, dark disc of dust in which an embryonic solar system is being
formed!
There is a lovely double star called Epsilon Lyrae up and to the left of Vega. A pair of
binoculars will show them up easily - you might even see them both with your unaided
eye. In fact a telescope, provided the atmosphere is calm, shows that each of the two
stars that you can see is a double star as well so it is called the double double!
Between Beta and Gamma Lyra lies a beautiful object called the Ring Nebula. It is the
57th object in the Messier Catalogue and so is also called M57. Such objects are called
planetary nebulae as in a telescope they show a disc, rather like a planet. But in fact
they are the remnants of stars, similar to our Sun, that have come to the end of their life
and have blown off a shell of dust and gas around them. The Ring Nebula looks like a
greenish smoke ring in a small telescope, but is not as impressive as it is shown in
photographs in which you can also see the faint central "white dwarf" star which is the
core of the original star which has collapsed down to about the size of the Earth. Still
very hot this shines with a blue-white colour, but is cooling down and will eventually
become dark and invisible - a "black dwarf"! Do click on the image below to see the large
version – it’s wonderful!
M56 is an 8th magnitude Globular Cluster visible in binoculars roughly half way between
Alberio (the head of the Swan) and Gamma Lyrae. It is 33,000 light years away and has
a diameter of about 60 light years. It was first seen by Charles Messier in 1779 and
became the 56th entry into his catalogue.
M56 - Globular Cluster
Cygnus
Cygnus, the Swan, is sometimes called the "Northern Cross" as it has a distinctive cross
shape, but we normally think of it as a flying Swan. Deneb, the Arabic word for "tail", is
a 1.3 magnitude star which marks the tail of the swan. It is nearly 2000 light years away
and appears so bright only because it gives out around 80,000 times as much light as
our Sun. In fact if Deneb where as close as the brightest star in the northern sky, Sirius,
it would appear as brilliant as the half moon and the sky would never be really dark
when it was above the horizon!
The star, Albireo, which marks the head of the Swan is much fainter, but a beautiful
sight in a small telescope. This shows that Albireo is made of two stars, amber and bluegreen, which provide a wonderful colour contrast. With magnitudes 3.1 and 5.1 they are
regarded as the most beautiful double star that can be seen in the sky.
Alberio: Diagram showing the colours and relative brightnesses
Cygnus lies along the line of the Milky Way, the disk of our own Galaxy, and provides a
wealth of stars and clusters to observe. Just to the left of the line joining Deneb and
Sadr, the star at the centre of the outstretched wings, you may, under very clear dark
skys, see a region which is darker than the surroundings. This is called the Cygnus Rift
and is caused by the obscuration of light from distant stars by a lane of dust in our local
spiral arm. the dust comes from elements such as carbon which have been built up in
stars and ejected into space in explosions that give rise to objects such as the planetary
nebula M57 described above.
Deneb, the Arabic word for "tail", is a 1.3 magnitude star which marks the tail of the
swan. It is nearly 2000 light years away and appears so bright only because it gives out
around 80,000 times as much light as our Sun. In fact if Deneb where as close as the
brightest star in the northern sky, Sirius, it would appear as brilliant as the half moon
and the sky would never be really dark when it was above the horizon!
There is a beautiful region of nebulosity up and to the left of Deneb which is visible with
binoculars in a very dark and clear sky. Photographs show an outline that looks like
North America - hence its name the North America Nebula. Just to its right is a less
bright region that looks like a Pelican, with a long beak and dark eye, so not surprisingly
this is called the Pelican Nebula. The photograph below shows them well.
The North American Nebula