Download Sample edition of skynotes

Star chart correct for 1st Oct (23h UT), 16th Oct(22h UT), 31th Oct (21h UT).
le
Moon position correct for 23h UT on day indicated by number nearby.
Planets correct for the beginning of the month
mp
7
6
5
●♃
4
31
3
30
2
29
1
28
27
26
25
Sa
24
23
22
21
20
© 2012 Scarborough & Ryedale Astronomical Society, All Rights Reserved
Not to be reproduced in any format without prior written consent from SARAS
Welcome to the October edition of skynotes. I started work on this edition the
weekend following Starfest, sat at Cadwell Park British Superbike meeting. There
was a thunderstorm overhead producing hailstones the size of marbles! and constant
thunder and lightning. I’m so glad I didn’t take my solarscope!
I have decided to send out PDF Skynotes to everyone on email. If you don’t want to
le
receive it in PDF let me know. Some of you have already done this. I still need to
know if you wish to receive it in its paper format.
This months edition is a bumper one. There are plenty of images to drool over from
Starfest as well as the usual articles. I have also made it so you can click on an
article in the contents list and it should take you straight to that page. There are also
links to the people who are coming to give us talks. Click on their name and it will
take you to a website with information about them.
Mell Jeffery, F.R.A.S.
mp
Treasurer and Editor, SARAS.
October Star Chart
Front Cover
Welcome
2
Astronomical Events - October 2012
3
Moon
3
Mercury, Venus & Mars
3
Moon Chart
4
Jupiter, Saturn, Uranus & Neptune
5
Other Events
5
Constellations
5
Sa
Sun
Starfest Report
6
Starfest Thank You’s
8
Starfest Images
9
Member Section
Bob Christy
13
Planetary Volcanism - Andy Exton
14
Aries - Mell Jeffery
21
Newsletter
24
2
le
During all of the month except the very last day, the Sun is passing through the
constellation of Virgo. This constellation is the second largest, area-wise, in the
entire sky – the largest being Hydra (the swamp snake). On October 31 st around
00h00, it passes into Libra.
The Moon
mp
The Moon is at apogee, its furthest from the earth, on the 5th at 00h44, and at
perigee its nearest to the earth at 01h03 on the 17 th. Last Quarter Moon is on the 8th
at 07h34 high in the constellation of Gemini, to the upper left of Orion and is one of
the highest Last Quarter moons of the year. October’s New Moon takes place on the
15th at 12h03 in Virgo, near its brightest star Spica. The moon passes 3° south of
the sun at this time. The First Quarter Moon occurs on the 22nd at 03h33 in eastern
Sagittarius. The Full Moon at 18h50 on the 29th is often called the Hunter’s Moon,
named after Herne the Hunter, who leads the Yell Hounds across the early winter
sky, and whose ‘yelping’ can be heard in the skeins of wild geese migrating at this
time. Alternative ideas have been put forward for the name given to this Full Moon;
one idea is that as the moon is now higher in the sky when full, it gives more light
for poachers to stalk their prey. Another is that when the moon is high in the south
at midnight, the constellation of Orion the Hunter is completely clear of the SE
horizon for the first time since last winter. Look for the Hunter’s Moon this year in
the constellation of Aries, 9° below the constellation’s brightest star Hamal.
You may observe the morning cone of the zodiacal light during the second half of the
month. Look for its ethereal glow in the morning sky from 15th to the 27th
The Planets
Although Mercury is an evening object reaching its greatest angular elongation of
24° east of the sun on the 27th, its low position near the SW horizon prevents it from
being seen. Indeed, at the time of greatest elongation it sets just 25 mins after the
sun.
Sa
Throughout October Venus continues to shine splendidly as the morning star, rising
around 4 hours before the sun. It is the brightest star-like object in the night sky
and casts a perceptible shadow on a sheet of white paper if you hold your finger up
between Venus and the paper in a dark corner of the garden away from external
lights. At the start of twilight around 04h30 on the 12 th, Venus will be seen at an
altitude of 15° in the east below the figure of Leo, with the thin waning crescent
moon 10° below the planet, near the horizon.
Mars continues to fade during October and is always low in the SW sky, almost lost
in evening twilight. On the 6th, it leaves the constellation of Libra and enters
Scorpius, and on the 18th the planet enters Ophiuchus and is a little dimmer than
most of the true bright stars in the sky. Mid month, Mars is two astronomical units
from earth (1 a.u. is the mean sun-earth distance). At the end of October Mars
climbs a little higher in the sky and sets almost two hours after the sun, and is
marginally easier to see. There is an opportunity to spot the thin waxing crescent
3
Sa
4
le
mp
moon and Mars within 5° of the SW horizon on the 18 th at 18h. At that time, Mars
lies 2° to the lower right of the crescent.
le
Jupiter (♃ symbol on the Star Chart) rises by 20h at the beginning of October and
by 18h at the end of the month, and is now shining steadily and serenely all night
long between the horns of Taurus the Bull. Before Venus rises, Jupiter is by far the
brightest object in the night sky. On the evening of the 5 th, the gibbous waning
moon may be seen rising 2° below Jupiter in the NE, when a pretty conjunction may
be witnessed around 21h. Look for the Galilean satellites in the usual well focussed
and firmly fixed binoculars.
Saturn is lost in evening twilight and on the 26 th lies in conjunction with, and far
beyond, the sun, to reappear next month as a morning object.
mp
Neptune is crossing the south meridian, ie is due south in the sky, at around 21h
during October. It is difficult to locate unless you have star maps as it is over five
times fainter than the faintest star visible to the naked eye, so is not excessively
bright in binoculars. This is not so with Uranus, which on the darkest nights is just
visible to the unaided eye. Once again though, it is necessary to know where the
planet is, in order to see it. Neptune is currently in Aquarius, and Uranus in western
Pisces.
Other Events
Sa
Some more remnants of Halley’s comet may be seen in the early hours of the 21 st,
when the earth encounters the Orionid meteor stream. Up to 25 shooting stars an
hour are expected. These meteors are fast moving and often leave persistent trains.
This year’s event should be favourable, as the moon, a broad waxing crescent, will
have set earlier in the evening. The biggest number of Orionids will be visible just
before dawn, when the constellation of Orion is high in the south. The radiant, or
point of origin of the shooting stars is some 10° above Betelgeuse, the star which
marks the right shoulder of the Giant Hunter. Earlier in the month on the morning of
the 8th, a slight increase in the number of shooting stars overnight marks the peak of
the Draconid or Giacobinid (whose parent body is the comet Giacobini-Zinner)
meteor shower, with its radiant in the constellation of Draco the Dragon. Last year
the earth passed through some concentrated filaments of particles, producing a high
rate of about 500 meteors an hour. It is not likely, although not impossible, that
there is a repeat this year. The moon is at last quarter later on in the day, and so
may interfere with the number od Draconids seen. The meteors have the reputation
of being slow moving but faint.
Constellations
Constellations visible in the south around midnight, mid-month, are as follows:
Cetus, Pisces, Aries, Triangulum and Andromeda. Cassiopeia and the Milky Way lie at
the zenith, with the Milky Way spanning the sky from east to west.
All times are GMT
1° is one finger width at arm’s length.
John Harper , F.R.A.S.
5
le
“...the Dalby forest night appears as good as "Kielder" and definitely darker than
the Kelling Heath sky in Norfolk…” - Mick Phipps.
Before I tell you about the Starfest weekend, I would like to thank all those members who
came to help. As we had quite a few people come forward to help it meant that jobs could
be allocated, rather than a few of us doing everything and then not getting the chance to
enjoy the weekend.
On the Wednesday a group of members went up to Adderstone field to set up the pitches
and rope off the site, the toilets where also delivered.
mp
This all took place before several of us arrived on site to set up camp! Jim and Sheila
Cornmell and Sue and Dave Greenwood had already pitched their tents before the rain and
ourselves arrived!
Poor Andrew got a soaking while pegging down the caravan awning! Mind you that was
nothing compared to the rain that came about 30 minutes later!
BUT when that weather front had cleared through, it left us with a beautifully clear night!
We got our 12” Revelation Dobsonian out and observed the following objects:
M22, M57, M31, M32, M110, M91, M81, M82, NGC404, Albireo, parts of the Veil Nebula,
M13 + Nearby Galaxy and M15. There was probably a few more objects, but I couldn’t
remember them all!
Sa
Thursday started out as a beautiful day. I had a meeting with Richard Darn to take some
pictures to help promote astronomy and in particular the Bat and Stars night on the 25th
August. I was lucky as I took Alicia with me and so they decided that she was far cuter than
me and so she got roped in for the photo session instead, much to her teenage disapproval.
The shots where taken at Haygate, just as you come into the forest. The pictures were then
used to accompany articles in the Yorkshire Post, Evening Press, Gazette and Herald and the
Mercury, these are the ones we are aware of, plus some online articles. I got my solarscope
out in the afternoon and had some brilliant views of sunspots, filaments and several large
prominences. It also saw the arrival of the people who were booked in to arrive that day. It
was nice to see people who I hadn’t seen for almost a year. Unfortunately the cloud came in
that evening and we were unable to do any observing, socialising was the order of the day,
or rather evening!
Friday didn’t start out very well, it was raining on and off, but that started to dry up come
the afternoon. The majority of people had by now arrived. The hogroast arrived and
everyone enjoyed it, some going back several times for seconds! It was also noted that it
was dry during the Hogroast, unlike previous years! There was still plenty of cloud about
that evening, with just the odd break here and there, but not really big enough patches to
break out the telescopes.
Saturday evening was similar! Several raffle tickets had been sold during Friday and
6
le
Saturday and that evening we held the raffle. Prizes included wine, books a few astronomical
observing items and a few other items. We were then treated to a talk by John Nichol. He
spoke about David Sinden—A life in Optics. That evening saw some large patches of clear
sky move over Adderstone Field, enough to get the telescopes out . John Harper helped us
to find some interesting objects one of them being Alamak ( Andromedæ) this is a double
star that is very similar to Albireo in Cygnus. Another interesting double that John pointed
out to us was Mesarthim ( Arietis), this looked just like 2 little cats eyes peering back at
you. I also managed to split  Lyræ, the Double Double! The Andromeda Galaxy was visible
but not as clear as on the Wednesday evening.
mp
Sunday saw some of our guests leave. This is normal, with Monday not being a bank holiday
like it was last year. Some of the site was taken down by the helpers ready for taking down
to the stores on the Monday morning. It also saw plenty of entertainment. We had the usual
rocket competition in the morning. As we had fewer children participating, it was decided to
let the adults have ago!! The children’s competition was won again by Hannah Jeffery (a
society member) and the adult competition was won by Keith Johnson. Later that afternoon
saw 2 members of Scarborough AS take on 2 members from North Devon AS at boules!
There was a late substitution when one member from North Devon AS took over from one of
the Scarborough AS members! The results were as follows: Mell Jeffery 8, Mark Buckingham
3, Andrew Jeffery / Julie Buckingham 1 and Rick Dooley 1! This also saw the arrival of
sunshine and solarscopes were in use again. Later that evening saw the Quiz. Quizmasters
this year were John Harper and Sheila Anderson, with Angela Taylor scoring. There was
plenty of booing, cheering and thinking going on amongst the 5 teams. The winning team
was, as usual, Durham (John, George and Juergen) followed by the Scarborough team
( Andy, Howard and Jim). We also had a second team consisting of Sue & Dave Greenwood
and David Trigg. After the quiz, Juergen gave a talk and the skies cleared. Everyone got
their scopes out and the skies delighted all those that remained. The only issue we had was
the amount of dew, this was possibly due to a heavy downpour we had during the quiz.
Some people retired due to the dew problem, but
some of the hardened imagers were up until 5:30
Monday morning!
Sa
Monday saw everyone left packing up and heading
home. It was a sunny day so no tents / awnings
were put away wet . And the rest of the equipment
was taken down to the stores.
Having checked my emails in the few days after
Starfest, it was nice to see plenty of people thanking
us for an enjoyable weekend and some even
sending us some of their images.
Alicia Jeffery (Society Member) at the ‘photo shoot’
for publicising the ‘Bat and Stars’ night with the
Forestry Commission. The event was the weekend
after Starfest, but the images taken in Dalby on
the Thursday of Starfest.
Image use courtesy of Richard Darn.
Mell Jeffery, F.R.A.S.
7
le
First of quite a few results from last night/
this morning.
I ended up staying out until around 0330,
but was very satisfied with the results.
If you want more details of this image or
more images from the set that I got just let
me know.
Thanks for the hospitality.
Hope to see you in 2013.
mp
Robert Williams
Just a quick note to thank you and your helpers for
another very social, friendly and (clear nights on
Thurs, Fri and Sat not withstanding!!) successful
Starfest.
I was down in Malton on Sunday evening under
clear skies till at least 2300, so though I didn’t
return on Sunday afternoon I trust some clear
spells were enjoyed with those that remained. I
was kicking myself for packing up completely on
Sunday morning
Sa
David Croston
On behalf of the members of the Border
Astronomical Society I just want to say a thank
you to all those involved for an enjoyable
Starfest last weekend.
The weather was much better than in previous
years and the helicopter display was very
impressive :-) We hope to see you all again next
year.
Regards,
David Pettitt.
Sec: Border Astronomical Society.
Dear Mell and all who tirelessly organize the Dalby Star Camp each year.
A big thank you again for a wonderful break in the forest, though I didn't get around to meeting you
this time - my apologies for that - I was very happy to be there again. After it seems several years
of waiting your efforts were finally rewarded with
a superb sky on Sunday after the Astro-mind. For what it's worth I can tell you that,
as a deep-sky observer for nearly 30 years now, the Dalby forest night appears as good as
"Kielder" and definitely darker than the Kelling Heath sky in Norfolk.
Long may the August Astro Camp continue.
Best Regards... Mick Phipps.
8
le
All of the following images have been reproduced with kind permission of the owner.
Friday Evening Sunset.
Sa
mp
Image credit: Keith Johnson
Andromeda Galaxy (M31) and
associated galaxies M32 and
M110
Image Credit: Keith Johnson
Triangulum Galaxy (M33)
Image Credit: Keith Johnson
9
le
Sa
mp
Starfest Campsite. Images Credit: Juergen Schmoll
Rocket Competition and Air Ambulance (Not for Starfest!) Images credit: Juergen Schmoll
10
The following 5 images are also credited to Juergen Schmoll
mp
le
M45 Pleiades
Sa
Summer Triangle
NGC 7000 North American
Nebula
11
Sa
mp
le
Veil Nebula
Triangulum
Galaxy M33
Solar Observing
Image Credit: Mell Jeffery
12
le
mp
Bob Christy, who is speaking at the November meeting is a recent arrival in
Scarborough. He originates from Kettering in Northamptonshire and, while at school,
developed a strong interest in satellites and space history. A major driver was being
a member of the Satellite Tracking Group at Kettering Grammar School which was
responsible for providing much in the way of detailed information on what was then
the Soviet Union's secretive space programme.
He continues that interest nearly fifty years later by publishing the "Zarya" web site
that specialises in current and historical space events. The site's emphasis is
providing information from a different angle to straightforward news stories. There
are analyses that pull in information from different directions, and added information
from actually tracking satellites in orbit using radio.
One of the most popular pages on the site is "Go for Launch!" which is a calendar of
upcoming events. It is updated daily and provides links to more-detailed news
sources, and webcasts of space events such as launches, and dockings at the ISS.
For skywatchers in Yorkshire, there are some special pages giving predictions for
highly-predictable flares from the Iridium telephone relay satellites. Many of you will
have seen one either by deliberately seeking it out, or by chance when one of them
reached magnitude -8 in the area of sky you just happened to be looking at.
For current events, there is a Twitter feed, or if anyone prefers, the same
information feeds through to Facebook.
Sa
Main site: http://www.zarya.info
The items mentioned above are all in the right hand menu:
Go for Launch! - http://www.zarya.info/Calendar.php
The Kettering Group - http://www.zarya.info/Kettering/Kettering.php
Astronomy for Yorkshire
IridiumFlare.php?site=SCA
(Iridium
flares)
-
http://www.zarya.info/AstroYorks/
Twitter and Facebook links are on the menu bar at the top of the page:
Twitter - https://twitter.com/Zarya_Info#
Facebook - http://www.facebook.com/pages/zaryainfo/150898915007077
13
le
mp
This month, I have decided to produce a 2 part planetary science article on volcanism which
will continue next month. What powers volcanism on Earth, where does it occur and is all
volcanism the same on Earth? Next month, I will look elsewhere in the Solar System to
explain evidence of past and present volcanism.
Unlike the Moon and other planets and satellites in the Solar System, the Earth shows little
in the way of impacts from asteroids and comets. Considering that the Moon and Earth
have shared the same region of space for around 4600 million years, it should be expected
that the Earth has had the same number of collisions per unit area as the Moon. Two
reasons exist for Earth’s uniqueness. Firstly, there is the existence of plate tectonics and
active volcanoes. Secondly we have an atmosphere, water and living organisms that
weather and erode the rocks and minerals at the Earths’ surface. Due to these processes,
Earth is termed a ‘Dynamic Planet’ (Webb et al, 2010).
The movement of tectonic plates and the production of magmas require heat. But what is
the source of this heat currently and throughout the history of the Earth? Well in fact, there
are 6 sources (Rymer and Drury, 2009), namely:
Heat of accretion: In planetary terms, the process of accretion is the growth of a
planet as a result of bombardment by fragments of rock and planetesimals (small
bodies several kilometres in diameter) (Allaby, 2008). The gravitational potential
energy of these rocky bodies accelerating towards Earth was converted to kinetic
energy and upon collision, this energy was converted, much of it being to heat (Rymer
and Drury, 2009).
Sa


Heat of compression: As a planetary body like the Earth grows in size during its
formation, the material towards the centre of the body becomes compressed with
material being accreted on the outside. The rocks undergoing compression as a result
become heated, with heat increasing significantly with depth due to the poor heat
conductivity of rocks (Rymer and Drury, 2009).

Core formation: The Earth has differentiated into a number of layers due to the
density of the materials forming them (Figure 1). Earth has a dense core, this being
surrounded by a less dense mantle, topped by an even lesser density crust. The dense
rocks that formed the core migrated there from shallower depths, sinking under the
influence of gravity due to higher densities compared to other Earth forming rocks.
Whilst sinking, this gravitational potential energy underwent conversion to heat (Rymer
and Drury, 2009).
14
le
Figure 1: Structure of Earth (USGS, 1999)
mp
Before moving onto the next two heat sources I will firstly explain the term isotope. An
isotope is an atom with the same number of protons but a different number of neutrons in
its nucleus compared to another atom. For example, hydrogen exists as three different
isotopes in nature; hydrogen (1 proton, no neutrons), deuterium (1 proton, 1 neutron) and
tritium (1 proton, 2 neutrons) (Daintith, 2008). Radioactive isotopes are those that are
unstable and hence undergo radioactive decay from a parent nuclide into a daughter nuclide
and releasing other nuclides or particles (Figure 2) with a half-life being defined as the time
taken for half of the original nuclides to decay (Daintith, 2005).
Short-lived radioactive isotopes: By short-lived radioactive isotopes, it is those
with half-lives less than 1 million years which compared to the age of the Earth is a
considerably short time. Early accreted materials into the Earths’ structure which will
have been formed from supernovae explosions will have decayed in the first few million
years, releasing energy that will have been trapped within the Earth (Rymer and Drury,
2009).

Long-lived radioactive isotopes: Radioactive isotopes are those with half-lives
longer than 1 million years. In the early history of the Earth, these contributed little in
the way of heating but are still important today.
Three radioactive isotopes
238
contributing to heating today are uranium-38 ( U), thorium-232 (232Th) and
potassium-40 (40K) (Rymer and Drury, 2009).
Sa

Figure 2: Radioactive decay of Uranium-238, producing an atom of Thorium-234
and a Helium-4 atom (Bodner).

Tidal Dissipation: The gravitational pull due to the motions of the Sun and Moon
result in the Earth being deformed, as well as the oceans and atmosphere (Figure 3).
15
mp
le
The deformation results in the Earth’s interior being heated due to friction (Allaby,
2008) and earlier in the history of the Earth, this effect will have been significantly
greater due to the orbit of the Moon being closer to the Earth (Rymer and Drury, 2009).
Figure 3: The effects of the Sun and Moon on the oceans. Note the Earth is also stretched
in this way although not shown in the image (HowStuffWorks)
Plate tectonic movements are very slow indeed with movements of only a few cm per year being
typical. In total there are around ten major plates that give the Earth a broken egg shell appearance.
From Figure 4, it is clear to see that the majority of volcanoes on Earth (red dots) are situated close
to the plate boundaries, with those surrounding the Pacific Ocean being termed the “Ring of Fire”.
Three different types of tectonic plate boundaries occur; divergent (constructive), convergent
(subductive) and transform (Blake et al, 2010).
Sa
Before moving on, I will firstly introduce two terms lithosphere and asthenosphere (you may have
noticed these two words on Figure 1). Tectonic plates are formed from slabs of lithosphere (‘lithos’
being the Greek word for rock). Lithosphere is the crust and the upper most part of the mantle
(around 100km) and they move together over the asthenosphere (‘astheneo’ being the Greek word
for weak), a weaker, partially molten layer that allows the lithosphere to flow over it. Lithosphere can
come in the form of continental or oceanic lithosphere. Oceanic lithosphere is basaltic in composition
and is generally 6-11km thick, forming the ocean floors.
Continental lithosphere forms the
continents; can be as thick as 90km and geologically is composed of igneous rocks rich in silica;
sedimentary rocks formed through erosive and biological processes; and metamorphic
(recrystallisation of igneous and sedimentary rocks as a result of heat / pressure reactions).
Convection in the mantle allows heat to be transported upwards to the base of the lithosphere, being
replaced by cooler, denser mantle, ultimately providing the heat source to aid tectonic movements
(Rothery, 2007).
Figure 4: Map of the Earth showing the tectonic plate configuration and the location of
major volcanoes (USGS, 1997)
16
le
mp
Figure 5: Simple diagram showing plate divergence (USGS,
2004b)
Sa
Divergent plate boundaries (Figure 5) are responsible for the
creation of new lithosphere.
The most common location for
divergent plate boundaries are in the form of mid-ocean ridges as
a result of a process known as sea-floor spreading, such as that found in the North Atlantic known as
the Mid-Atlantic Ridge (Figure 4). Another area home to a constructive plate margin is the Red Sea,
which is a young sea currently opening. Interestingly, the East African Rift Valley in Ethiopia may well
follow suit in the future (Rymer and Drury, 2009). A divergent plate boundary is believed to be
formed when convective currents in the asthenosphere having moved upwards diverge at the top of
the asthenosphere, causing a drag on the lithosphere above causing it to rupture. This rupture then
continues to move apart forming a divergent plate boundary. Molton rock fills the void and is quickly
cooled as a result of seawater, producing new oceanic lithosphere (USGS, 2004b). The continued
upwelling of molton rock produces mid ocean-ridges, which consist of underwater volcanoes and the
continued slow movement of the tectonic plates continues the formation of these ridges (Rothery,
2007).
Convergent plate boundaries can take the form of collisions between oceanic and oceanic (Figure 6),
continental and oceanic (Figure 7) or continental and continental plates (Figure 8) (USGS, 2004).
Figure 6: Simple diagram showing continental vs.
oceanic plate convergence (USGS, 2004a)
Oceanic plates are denser than continental plates so a
collision between plates of each type results in the denser
oceanic plate being forced downwards underneath the
continental plate. The downward motion of the oceanic
17
le
plate pulls the rest of the plate with it, entering the asthenosphere, forming a subduction zone. At
the point where the two plates meet, an ocean trench is formed (Figure 6). As the subducting plate
moves deeper into the asthenosphere, melting occurs due to temperature and pressure changes, as
well as the effects of water. This heated molton rock rises upwards as magma, producing volcanic
arcs on the continental crust. Magma may solidify below the surface forming magma chambers or it
may form volcanic eruptions that over time form volcanic mountain ranges (USGS, 2004). Examples
of these processes currently occurring include the West coast of South America and the North West
coast of North America (Rothery, 2007).
Figure 7: Simple diagram showing oceanic vs.
oceanic plate convergence (USGS, 2004a)
mp
Whereas a collision between oceanic and continental lithosphere results in the subduction of the
denser oceanic lithosphere; a collision between two slabs of oceanic lithosphere relies on the denser
slab being subducted (Figure 7). Oceanic crust is formed at divergent plate boundaries, and over
time the lithosphere cools and becomes denser; so the colder and older of the two plates is
subducted. The formation of an ocean trench and the melting of rocks occur as with the oceanic /
continental scenario but the eruption of magma at the surface does not occur on land. In this
scenario, the eruption occurs initially on the ocean floor but over time, the peaks of the volcanic
mountains break through the ocean surface and an island arc is produced. An example of this
scenario is the Aleutian Islands off the coast of Alaska (USGS, 2004a).
Figure 8: Simple diagram showing continental vs.
continental plate convergence (USGS, 2004)
Sa
Convergent plate boundaries can also collide with each other. As mentioned previously, continental
lithosphere is buoyant so when they collide, neither can be subducted (USGS, 2004a). As a result,
the plates become buckled and drive upwards against each other forming large mountain ranges
(Figure 8), eventually fusing the plates together. As no subduction zone exists, there is no source for
magma to rise upwards so mountain ranges created by this method are not generally associated with
volcanism. Examples of mountain ranges formed in this way are The Alps and The Himalayas
(Rothery, 2007).
Figure 9: Configuration of plates creating the San Andreas
Fault (USGS, 2004c)
In contrast, transform plate boundaries are neither responsible
for creating or destroying lithosphere.
The plates along a
transform boundary slide along each other, grinding as they
make contact with each other.
No magma generation is
18
associated with them but some of the world’s major earthquake zones lie along them. Possibly the
most famous example of such action is the San Andreas fault running through California (Figure 9)
resulting from the opposite movements of the Pacific and North American plates (USGS, 2004c).
le
However, some volcanoes appear in the centre of plates and are known as hot spots or intraplate
volcanoes, resulting from magmas erupting from below melting the lithosphere above. Whilst the
tectonic plate has the ability to move, the magma store remains fixed. Over a period of time, the
continued eruption of magma in one spot forms an island chain, as the plate above continually moves
away from the hotspot (Blake et al, 2010). A famous example of a hot spot is the creation of the
Hawaiian Islands chain (Figure 10).
Sa
mp
Figure 10: Formation of an island chain by a
fixed hot spot (USGS, 1999b)
To conclude, it is clear to see that the Earth
is an active body with numerous constructive
and destructive processes occurring, which
over many millions of years have reshaped
the continents and moved them to their
current configuration (Figure 11). It is these
tectonic
processes
along
with
other
geological processes including erosion and
deposition
that
have
resurfaced
the
continents. This is believed to be the reason
that historical meteorite and comet impacts
that have cratered other planetary bodies
have been obscured here on Earth.
Figure 11: Continental movement
throughout the past 225 million years
(USGS, 2012)
19
References:
Allaby, M. (2008) Oxford Dictionary of Earth Sciences (3rd Edition), Oxford University Press,
Oxford
le
Blake, S., Argles, T., Harris, N. (2010) Magmas and Mountains, S276 Geology(Book 2),
Open University Press, Milton Keynes
Bodner (2012) Radioactive Decay, Bodner Research Web http://chemed.chem.purdue.edu/
genchem/topicreview/bp/ch23/modes.php [Accessed 7 September 2012]
Daintith, J. (2005) Oxford Dictionary of Physics (5th Edition), Oxford University Press, Oxford
Daintith, J. (2008) Oxford Dictionary of Chemistry (6th Edition), Oxford University Press,
Oxford
mp
HowStuffWorks (2008) How Ocean Currents Work, How Stuff Works http://
science.howstuffworks.com/environmental/earth/oceanography/ocean-current4.htm
[Accessed 7 September]
Rothery, D. A. (2007) Teach Yourself Volcanoes, Earthquakes and Tsunamis (2nd Edition),
Hodder Education, London
Rymer, H., Drury, S. (2009) Earth’s Engine (4th Edition), S339 Understanding the Continents
(Book 1), Open University Press, Milton Keynes
USGS (1997) Active Volcanoes, Plate Tectonics, Hot Spots and the Ring of Fire, United
States Geological Society http://vulcan.wr.usgs.gov/Glossary/PlateTectonics/Maps/
map_plate_tectonics_world.html [Accessed 7 September 2012]
USGS (1999a) Inside the Earth, United States Geological Society http://pubs.usgs.gov/gip/
dynamic/inside.html [Accessed 6 September 2012]
USGS (1999b) “Hotspots” Mantle thermal plumes, United States Geological Society http://
pubs.usgs.gov/gip/dynamic/hotspots.html [Accessed 7 September 2012]
USGS (2004a) Convergent Plate Boundaries, United States Geological Society http://
geomaps.wr.usgs.gov/parks/pltec/converge.html [Accessed 10 September 2012]
Sa
USGS (2004b) Divergent Plate Boundaries, United States Geological Society http://
geomaps.wr.usgs.gov/parks/pltec/diverge.html [Accessed 13 September 2012]
USGS (2004c) The action is at the edges, United States Geological Society http://
geomaps.wr.usgs.gov/parks/pltec/pltec3.html [Accessed 13 September 2012]
USGS (2012) Historical Perspective, United States Geological Society http://pubs.usgs.gov/
gip/dynamic/historical.html [Accessed 13 September 2012]
Webb, P., Argles, T., Sheldon, P. (2010) Minerals, Rocks and Maps, S276 Geology(Book 1),
Open University Press, Milton Keynes
20
le
The ram has played various roles in mythology and in religion. For example, the
Egyptian God of Fertility and Creative Life was depicted as a creature with the body
of a man and the head of a ram.
mp
One mythological story is that of King Athamas of Boetia (Asia Minor). His Queen
was a Goddess, Nephele. Although it was common for mortals to marry Gods/
Goddesses, they weren’t allowed to stay on Earth indefinitely. When she had to leave
she left her son, Phrixos and her daughter, Helle in the care of the King. Soon after
he remarried. The children’s Step Mum, Ino, eventually turned against the children
and tried to get rid of them. She spread disease in the crops, which caused the
harvest to fail and then spread rumours that the Gods were angry with the 2
children. Ino corrupted the Priests, who advised the King that his children should be
sacrificed.
Nephele saw what was happening and during the night came down from Olympus
and planned a rescue. When the time came for the children’s execution and they
were led to the alter, a golden ram descended. They climbed aboard its back and
were told not to look down as it leapt into the air.
Helle could not resist the temptation to look down and as she did she fell off the ram
and into the sea. Phrixos, however, arrived safely and the ram was sacrificed to
Jupiter, although some say it was Zeus. He gave its golden fleece to King Aeëtis and
its body was placed amongst the stars.
There is another story of a ram involving Odysseus and this is were the astronomical
meaning for the myth can be seen. Odysseus was brought, by a ram, from a dark
cave into the light and this symbolises when the Sun is in Aries, the long dark winter
Months are over and the sun shines for longer spreading its warmth.
Sa
From 1730BC to 420AD, Aries was the constellation of the first day of Spring, but
due to the procession(1) of the equinoxes(2) this is now Pisces. Come 24,100AD the
Vernal equinox will again be in Aries.
Aries is situated below the constellation of Triangulum, between Taurus and Pisces.
At first glance it seems an inconspicuous area of sky, with only 4 stars above 4.0
magnitude and no Messier or Caldwell objects! But on research, there is more to be
seen.  Arietis, Hamal, is twice the size of our Sun and is reddish. Mesarthim, 
Notes:
1 - Procession - The apparent movement of the celestial poles due to the Earths ‘wobble’.
2 - Equinox
- When the Sun crosses the celestial equator.
21




R



le

  





Object
mp

Name
Type
Magnitude
Hamal
Star
2.01
Sheratan
Star (spectroscopic binary)
2.64
Mesarthim
Double Star
Both 4.8 (Sep 7.8”)
Botein
Star
4.35
Double Star
5.2, 5.5 (Sep 1.5”)
Double Star
4.8, 6.7 (Sep 36.7”)
Double Star
5.2, 8.7 (Sep 1.5”)
Star
3.61
R Ari
Variable
7.4 - 13.7
NGC 673
Galaxy
13.2
NGC 678
Galaxy
13.3
NGC 680
Galaxy
12.9
NGC 691
Galaxy
12.3
NGC 770
Galaxy
14
Galaxy
10.3
NGC 821
Galaxy
11.8
NGC 877
Galaxy
12.6
 Ari
 Ari
 Ari
 Ari
 Ari
Sa
 Ari
 Ari
41 Ari
NGC 772
Bharani
Fiddlehead Galaxy
22
Arietis, is a binary star and sometimes referred to as the ’Ram’s Eyes’. Both
components are white with a separation of 7.8 arcseconds. It was discovered by
Robert Hooke in 1664. The star with the designation 41 Arietis was not given a
Greek letter as it was originally part of a constellation called ‘Musca Borealis’ or the
Northern Fly!
le
There are quite a few NGC objects, but they are very dim. Probably the easiest one
to try to find would be NGC 772, the Fiddlehead Galaxy. This object is also listed as
‘hidden treasure no: 8’ in Stephen O'Meara's Deep Sky Companions book - Hidden
Treasures. It is a spiral galaxy with NGC 770 lying close by and possibly a
companion galaxy. I have listed a few other NGC objects, but all are very faint.
Incidentally, the gravitational pull from NGC 678 appears to be distorting its elliptical
neighbour, NGC 680!
mp
R Arietis is a Mira type variable with a period of 186.8 Days. There is also U Arietis
which is also a Mira type with a period of 371.1 Days. Another notable variable star
is T Arietis, this is a semi regular variable.
There are several faint meteor showers associated with Aries.
Sa
Mell Jeffery, F.R.A.S.
Aries, The Ram and Musca
Borealis, the Northern Fly
(the constellation is no
obsolete) as depicted in
Urania's Mirror, a set of
constellation cards
published in London c.1825
References:
O’Meara, Stephen. (2007) Deep Sky Companions - Hidden Treasures, Cambridge University Press.
Hass, Sissy. (2006) Double Stars for Small Telescopes, Sky Publishing, Cambridge, Massachusetts.
Ridpath, I. (2004) Norton’s Star Atlas (20th edition), Pi Press, New York.
Tirion, W. (2005) The Cambridge Star Atlas (3rd edition), Cambridge University Press.
Moore, P & Rees, R. (2011) Patrick Moore’s Databook of Astronomy, Cambridge University Press.
Staal, Julius. D. W. (1988) The New Patterns in the Sky, Myths and Legends of the Stars, The
MacDonald & Woodward Publishing Company.
http://en.wikipedia.org/wiki/Aries_(constellation) [Accessed 13 September 2012]
Starry Night Pro Software Version 6.4.3
23
Scarborough & Ryedale
Astronomical Society
le
Founded: 1976
Registered Charity No: 1092385
Honorary President: Mr John Harper, F.R.A.S.
Website: www.scarborough-ryedale-as.org.uk
Newsletter, 17th September 2012.
mp
Welcome to the first edition of Skynotes of our new season. I would like to start by
welcoming some new members:
Derek & Louise Brazil & Family
Gary Welford
I would also like to thank all those who were able to help with Starfest, especially those who
were able to set up the field on the Wednesday. Starfest was a great success as ever and we
had some clear skies too.
Our first Public Viewing Night will be upon us soon, Friday October 5th at Dalby. If you are
able to come along and help, please do so, the more the merrier.
Andy Exton has done a great job sorting speakers for the coming meetings, as you will see
he has about filled every available slot! If you are receiving the PDF version you will be able
to click on the speakers name and it will open up a page on the internet relevant to that
person.
Sa
We are in the process of sorting out a venue for the Christmas meal. All information should
be available next month. It will be in Skynotes, but also emailed out.
Up Coming Events:
October 5th
Public Viewing Night at Dalby.
October 19th
Open Evening. (Originally publicised as beginners night)
October 20th
Joint event with Humble Bee Farm.
November 2nd
Public Viewing Night at Dalby.
November 16th
Society Member Bob Christy, with a talk titled ‘Satellite Tracking Half a Century!’
December 7th
Public Viewing Night at Dalby.
December TBC
Christmas Meal.
24
Public Viewing Night at Dalby.
January 18th
Change of Venue: Sawdon Village Hall. Members / Social Night.
Change of venue due to darker skies.
February 1st
Public Viewing Night at Dalby.
February 15th
Paul Money with a talk on the Messier Marathon.
March 1st
Public Viewing Night at Dalby
March 15th
Dr Pete Edwards (Durham University) - Bringing the Universe
down to Earth. (A talk about some of the space related questions of
CERN and the LHC)
April 19th
Dr Janet Humphreys (Formerly of Leeds University and OU S282
(Astronomy) Tutor) - Cosmic Recycling (A talk on the formation of
elements, stars and planets etc)
May 17th
Dr Simon F. Green (Open University) - Missions to Asteroids:
Exploring our origins and Saving the World! (A talk on why we are
interested in Asteroids, previous and future missions to them)
July 19th
mp
June 21st
le
January 4th 2013
August 9th - 12th
Dr Lee Sproats (Green Witch Telescopes) - Telescopes of the
Future (A talk on some of the planned telescopes and where
telescope design may head in the future)
TBC
Starfest
The following has been sent out in an email, but just in case you didn’t get it, here it is.
Following a chat with Joseph Gordon from Newcastle Astronomical Society over the weekend at Starfest he has
sent me the following information. They have decided to hold a star party at Haltwhistle, close to Hadrian’s Wall
over the 7th and 8th December. Anyone interested or would like further details, please e-mail Joseph at
[email protected] .
Star Party 7th and 8th December 2012
Sa
Hello lads and lasses - advance notice of a star party.
Organising body to be decided.
Once we have more details they will be forwarded out.
Standard star party format - hog roast etc.
People can book up and arrive before the main event - and of course stay longer and enjoy the area of Hadrian’s
Wall.
Check out the link BELOW for details.
https://www.facebook.com/pages/Herding-Hill-Farm-Shop-Tea-Room-Caravan-Camping-andWigwams/223840004294856?ref=ts
Please let me know if you would like to attend, how many on your party and whether your camping
Caravanning / motor home or using the Wigwams.
Booking information and event details to follow.
Thanks
Joe
25
I do hope we all manage to get some decent observing sessions in this winter.
Don’t forget we have plenty of knowledgeable members within the society should
you be stuck and need a question answering, so don’t be afraid to ask.
le
We also have the society forum for posting questions, images and observing reports,
amongst other things. This is accessed through the society website. We also have a
Facebook page to keep you and anyone else up to date with what’s happening within
the society. The web address for the Facebook page is:
https://www.facebook.com/ScarboroughRyedaleAstronomicalSociety
Clear Skies
Andrew Jeffery
mp
Chairman, S&RAS.
‘That’s one small step for [a] man,
one giant leap for mankind!’
Neil Alden Armstrong
August 5th, 1930 - August 25th, 2012
Acknowledgements
Star Chart: Starry Night Pro Version 6.4.3
Moon Phase: LunarPhase Pro Version 3.35
Sa
Astronomical Events: John Harper, Sheila Anderson.
Other: Mell Jeffery, Bob Christy & Andy Exton.
Treasurer
Mrs Mell Jeffery, F.R.A.S.
11 Chestnut Grove
Norton
Malton
North Yorkshire
YO17 9BZ
01653 691128
s&[email protected]
Chairman
Secretary
Andrew Jeffery
11 Chestnut Grove
Norton
Malton
North Yorkshire
YO17 9BZ
01653 691128
[email protected]
26
[email protected]