Observatory Articles and Reports
The velocity of Light - National Astronomy Week 2014.
National Astronomy Week (1st – 8th
March) was when all good astronomers dusted off their telescopes and got
outside. This year Jupiter was the featured planet, it was so close and
therefore so bright that no one could miss it. A challenge was set up to
see if local Astronomy Societies could get close to the true value of
the speed of light and we were going to try and join in.
In the event the clouds got the better of us plus the
research to find out more about the history of Romer’s search proved
more difficult than anticipated.
It was Ole Romer, the Danish astronomer, who made a
set of observations between 1671 & 1677 and based on best estimates of
distance at the time to calculate a reasonable figure for the speed of
light. The technique he used was based on eclipses of the satellites of
Jupiter. Romer like scientists before and after him "stood on the
shoulders of giants" to advance his work
Copernicus in 1543 suggested that the Earth and all
the planets orbited the Sun.
Kepler in 1609 and 10 wrote his 3 laws the last of
which stated that T 2 = R 3 this is easy to
interpret if T is in years and R in astronomical units. This allowed
astronomers to define the distances in terms of the AU for all the
planets of the Solar System. Galileo first saw the moons of Jupiter in
In 1678 Newton unravelled gravity G to give a
quantitative interpretation of Kepler’s Laws. GCSE Book
There was one problem faced by the early astronomers
– they were able to obtain comparative figures of distance from the Sun
of the various planets using Keppler’s Laws but an absolute distance
eluded them. However the transits of Venus 1761 and 1769 allowed rough
figures to be obtained. Better figures were obtained in 1874 and 1882
and they were analysed afterwards By Encke. Midnight Sky p191 see
also Jeremiah Horrocks by Paul Marston. Clearly these
events had not yet taken place in the 17th cent so
alternative must have been used.
David Gill. It is well known that Gill in 1877
measured the parallax of Mars on Ascension Island. Dic. Scien
Bio.p417. Perhaps this too built on earlier work?
Jean Cassini, although he rejected the idea that
light had a finite velocity nevertheless was the first to arrive at a
figure for the distance of Mars in 1672. He took advantage of a good
(early September) opposition by sending Jean Richer to Cayenne, on the
north east coast of South America. Cassini stayed in Paris at the Paris
Observatory. This gave a baseline of nearly 10,000 km for a
triangulation of Mars. The results derived for the AU were 138 million
km about 11.6 million km less than the value accepted today. Dic
Scien Bio p221.
Romer's method diagram
Ole Romer used Cassini’s results to measure the
speed of light. He was aware that the length of time between eclipses of
Io was not constant. He calculated the time in 1675 when Jupiter would
be closest to Earth (early June) i.e at opposition and observed that at
that time the interval between eclipses was also smallest. He continued
for a number of years taking measurements. In Sept 1679 Romer announced
that on the 9th November the eclipse would actually take
place some 10 minutes later than other astronomers had predicted. He
was, of course, correct and stated that the cause was the extra distance
the light had to travel as the distance between the two planets was now
larger than before. He estimated the speed at 225,000 km/sec pretty
close to today’s figure of rather less than 300,000 km/sec. Dict
Romer recorded the difference it time it took light
to reach him comparing the time taken when the Earth was closest to
Jupiter with the time taken when the Earth was furthest from Jupiter i.e
6 months later. He found it to be 22 minutes, later more accurate
observations gave 16 minutes 38 seconds. The distance 186 million miles
the time in seconds 1000 hence the speed of light is 186,000 miles per
second. General Astronomy H. Spencer Jones Page 240.
Tragically only one series of Romer’s observations is
still in existence, all others were consumed by the flames of a great
fire in 1728 in Copenhagen. A concise history of astronomy Peter Doig
"The satellites move from east to west across the
face of the planet, and from west to east behind it. After conjunction
with the Sun and before opposition, the shadow of Jupiter falls to the
west, eclipse precedes occultation, and shadow-transit precedes transit.
After opposition, the order of the phenomena is reversed, occultation
preceding eclipse and transit preceding shadow-transit." BAA Handbook
Due to fact that Jupiter was past opposition during
National Astronomy Week 2014 it only was possible to use the time of
emergence of Io the innermost of the moons of Jupiter.
An analysis of the times that Io remains eclipsed
showed a steady increase from the beginning of January when Jupiter was
in opposition until early June when it is in conjunction with the Sun.
National Astronomy Week website.
actual Society running this event for NAW is Orwell AS www.oasi.org.uk
To keep an eye on Jupiter use the planetarium
programme "Stellarium" which not only tells the observer which
moon is Io but also the distance of Jupiter from Earth. Over a period of
time as the distance increases so does the length of time in eclipse,
when two or more results have been obtained the speed of light can be
calculated. Clearly the greater the number of results the closer we get
to a true figure of the speed of light.
The plan is to submit timings to Orwell and they will do the
calculation! NB Stellarium can be downloaded from www.stellarium.org it
is free and works on most Computer Platforms.
Further reading;- The story of the heavens by
Robert Ball in 1890 on P222 and also in Outlines of astronomy by
John Herschel in 1869 on P364. Astronomy by Flammarion published in
French 1880 translated from the French edition 1955-60 translated and
revised and updated 1964 P303 et seq
Also noted en route;-
James Bradley, well aware of Romer’s work,
attempted to measure stellar parallax although he was unsuccessful – due
to a lack of sensitivity of his equipment however he did discover
aberration or nutation using a telescope pointing to the zenith. He also
calculated that it took light 8 min 12 seconds to reach Earth from the
Sun, only 8 seconds out. Cam Hist Ast P215 Bradley improved on
Romer’s work some 60 years later with a figure of 308,000 km/sec. Dic
Scien Bio P210 Romer estimated that light took about 11 minutes to
travel from the Sun to the Earth!
Names of the Galilean moons;- In the old (18th/19th
Century) astronomy books the satellites are just given numbers I, II,
III, IV. However it seems that the names we use today were unofficial
Io, Europa, Ganymede and Callisto were the choice of Simon Marius, a
German who discovered them at about the same time as Galileo. See
Hanlon’s book detailed below. Today the IAU give the official names
of all things astronomy. They were set up in 1919. Patrick Moore in
his handbook, the Practical Astronomer first published 1957 observed
that they came into general use about that time. For nice account of the
origin of the names see The Data Book of Astronomy by Patrick Moore
Reason for the colour of Jupiters Belts.
In 1953 Stanley Miller and Harold Urey passed
electric sparks through a mixture of hydrogen, methane, ammonia and
water vapour to produce a brown mixture of amino acids. These are the
compounds that are the building block of proteins.
In the 1970’s the experiment was repeated using
methane or acetylene together with ammonia cooled to the temperature of
liquid nitrogen a reddish brown polymeric material was produced. The
colour match between this mixture and the bands on Jupiter is very
close. It was thought that this process might indeed be responsible for
the colours in the atmosphere of Jupiter. Pioneer – First to Jupiter,
Saturn and beyond published by NASA 1980.
When Galileo launched in 1989 is was programmed to
end its time by crashing into the planet in 2003. Its probe was designed
to relay information about the atmosphere of Jupiter as it flew deep
into the planet via Galileo and then to Earth. It found little evidence
of organic molecules apart from methane, propane and butane and no
evidence of amino acids. The reason can be found in the way the
atmosphere churns around, plunging deep toward the core of the planet to
temperatures too hot for any complex organics to survive. The worlds
of Galileo – the inside story of NASA’s mission to Jupiter. By Michael
A picture of Romer with his Transit Instrument A5
size a history of astronomy by Charles-Albert Reichen
star appeared in the galaxy known as M82 which is in Ursa Major. It was
spotted by a group of students working at the University of London's
Mill Hill Observatory. This type 1a supernova is pretty close, a mere 12
million light years distant.
Stewart Ledbury of the Observatory imaging team was quickly on the
case. The bright dot just above the red centre is the super nova. Well
Image Credit - Stewart Ledbury
Explosions of this type are caused by when the white dwarf takes gas
from a binary companion to such an extent that the white dwarf explodes.
Typically this type increases in brightness over a period of about two
weeks before decaying over a few months.
The images that follow are by David Strange (copyright) of the
Norman Lockyer Observatory - Devon.
David has kindly added the following;-
are several images, also caught another one last night. (1st Feb) The
spectrum shows a typical broad Si II absorption line of a Type 1a
supernova. This is blueshifted to 6097 from its rest energy of 6355A
which indicates a sn shell expanding at 12,000 km/s. On last night's
spectrum the Si II line was showing less blueshift and narrowing, now
indicating a drop in velocity. The image also shows H alpha emission
from the galactic core, as this is a very active galaxy. The colour
image taken with 1 hour total exposure time with a OSC SXVR-H9C colour
camera, shows the sn as a decidedly orange/red colour. This is due to
the intergalactic dust in M82 which has absorbed much of the blue light
in the spectrum,
showing an unusually reddish spectrum for such an object.
Mike Sale visited Mercury Bay in New Zealand where Captain Cook
observed the transit of Mercury on the 9th of November 1769.
These images will be used again when Mercury crosses the Sun in
"On the 9th the Indians brought a prodigious quantity of mackerel,
which they sold at a low rate, and the cargos purchased were so great
that the ship's company cured as many as would serve for a month's
provision. This being a clear day, Mr. (Charles) Green, the astronomer,
landed with some of the gentlemen to observe the transit of Mercury.
The observation of the ingress was made by Mr Green alone, and Captain
Cook took the sun's altitude to ascertain the time...... The weather
being favourable, the transit of Mercury was viewed without a cloud
intervening. In consequence of this observation being made here,
this bay was called Mercury Bay."
Green was born in 1735, worked for a while at the RGO starting
in 1761 he died at sea with Captain Cook on the 29th January 1771.
to Monty who as a 10 yr old is thought to be the youngest holder of a
GCSE astronomy pass (B) ever.
Monty as he appeared in the London Metro
The Stargazing LIVE interview for Radio Cornwall.
The ITV Westcountry News
interview at the Observatory.
January 2013 Prize Presented;- As a follow up to the main event
Mike Astro made a model rover to be given to the standout driver on the
evening. Thomas Austin of St Columb Minor primary school was selected
and on the 20th it was presented in the presence of his family and
Steve Serevena (SS Computer Services) who ran our end of the Mission. We
were joined by Mike and his wife Anna from Shetland via Google+ - that
was great. Also of course the local Press were there - thanks to them.
Thomas with model Rover made in Shetland.
Mission Control was controlling a Mars Rover that actually was in
Village Hall in the Shetlands, some of our visitors were able to drive
Link to the Youtube
If the link does not
open copy directly into your brower's tool bar.
Sir Patrick Moore has died ;-
the end of an era - an irreplaceable character. A lot has now been
written about the great man's contribution to astronomy. Everyone knows
about Sky at Night but his books were of the gold standard variety if he
said it must be true! He wrote about the night sky, about specific
planets and text books like his Data Book of Astronomy. He also had time
for those new to the hobby. I still have a postcard giving me advice on
liquid objective lenses written when I was in the 6th form. I have one
regret that I was unable to find time to visit him to say "good bye"
like everyone else thought it would never happen. I am sad that those
who never knew him will never be able to "stand in his shadow" and ask
his opinion on one topic or another.
Patrick Alfred Caldwell-Moore
Pinner, Nineteen Twenty Four,*
survived as wartime bomber.
Fiancée killed, flame carried,
plainly it was not to be,
result, he never married,
‘Second best, no good to me’.
Became opponent of war,
made Moon Maps; ‘Sky at Night’,
which on BBC we saw,
before ‘Sputnik’ satellite.
‘Monster Raving Looney’,
pianist while Einstein fiddled.
celestial ‘scopes twiddle.
Patrick on his visit to the Observatory several years ago.
Image credit Paul Hughes
Devington Hall, Truro
David is an old friend of mine from our lab days. He
is a regular contributor to community
team recently won the Golden Microphone Award. from Source FM for their
One & All Show. He is their poet. Thanks David
Martin, part of the Observatory team, recalls that while working
at Heathrow in 1986 he spotted Patrick leading a tour party to see
Halley's Comet even then he had time to autograph one of Martin's
books. He had time for every one - pretty rare that is.
Meteor Showers in calendar
The Quadrantids 3rd - 4th Jan
This shower is named after an obsolete
constellation Quadrans Muralis that used to be located at the junction of
Ursa Major, Hercules and Bootes. It was Lalande, who became Director of
the Paris Observatory, who created it in 1795 to commemorate an instrument
he used to measure the position of more than 47,000 stars in the company
of Nicole-Reine Lepaute one of the early female astronomers and his nephew
Michael Le Francais. As a
constellation it only lasted for some fifty years before it was left out
of later star charts. It does not appear to be popular in the UK. This
is rather strange because in 1763 he was not only living in London but
was used as an interlocutor between Harrison, the British clockmaker,
and Berthoud his French counterpart in the Longitude affair. However of
course the British and the French were always having Local Difficulties
at that time.
John Milton in Paradise Lost has the following;- Th' Imperial
Ensign, which full high advanc't Shone like a meteor streaming to
the wind With Gems and Golden Lustre rich imblaz'd Seraphic arms and
Trophies; Shone like a meteor streaming to the wind.
This shower has not been recorded for a long time in history - one of
the early records was by Quetelet in 1839. All meteor showers originate
from comets, however, it was not until 2003 that Peter Jenniskens compared
the orbit of 2003 EH1 with the Quadrantids and found them similar - the
problem was solved. 2003 EH1 is now classed as an "asteroid" but
is believed to be the remains of a comet which broke up some 500 years
Halley's 1725 Mural Quadrant
How the number of meteors varies before and after midnight.
Observing this shower has
always been difficult with only about one year in four giving clear skies.
This year the peak is centred around 01.00hrs on the Sunday 4th the radiant that this time
will be due north and not very high. Unfortunately the rather large Moon will interfere,
so get high before
19.00hrs with a
clear view north, the peak period is not expected to last more than an
hour or so. The period of maximum rate is 80+ per hour.
A bonus can be a very bright bolide or exploding meteor. Apparently
the best way to watch this shower is from the comfort of a "Hot
There could well be a second surge before dawn as the Earth drives into
the dust particles.
www.meteorwatch.org for more info. updated for 2015. (The ZHR is
given at 100, this is a theoretical number that can be seen should the
radiant be at the zenith the the observer has 360 degree vision!)
The Lyrids ;- 22nd/23rd April. This is good news
as we have had a long time to wait since the last shower. The
radiant of this shower is a shade SW of Vega which rises about 9.00pm in
the NE. Vega is one of the brightest stars in the sky and is pretty
visible. As usual the best time to watch is after midnight. As
with all showers there is a parent comet, in this case it is Comet
Thatcher, discovered by Galle in 1861 and the shower has been
recorded since 687 BC. These days we can expect only a few per hour
but some can be pretty bright and leave behind a smoky trail. Lets hope
for clear skies. The bright star is Lyra, the meteors appear to come from
an area close to it. Image credit Spaceweather.com
Eta Aquarids peak
on the early hours of May 6th. This shower is
linked with the most famous comet of them all Halley's of course. It
has been noted as far back as 401BC. It was the grandson of William
Herschel - Alexander who calculated that the radiant of the meteors
corresponded to the intersection of the orbit of the comet with the
Earth's orbit in 1876. A problem each year with observing this shower is
that it is a dawn event, the radiant only rising above the horizon an
hour of so before dawn which is 5.30am BST. For those living south of
the UK up to 30 may be seen each hour. we will not be so lucky. The
waning Moon will be only 4 days before New and so will not interfere
very much. Also of course the meteors shoot in all directions hence can
be seen well before dawn. Like all daylight showers it can be followed
"on radio" by visiting Andy Smith's site
Although the peak is now past the rearguard may be seen
on any clear night for a few more days.
image from Universe Today
the radiant is close
to the Pole Star and will peak in the early hours of May 24th. (Best
pronounced Camel opardal ids)
The parent comet
is called 209P/LInear was found on Feb 3, 2004. It was closest to the
Sun on May 6th and will be closest to the Earth May 29 when it will be
at mag 11. it was first thought to be a minor planet (asteroid). However
on March 30 it was seen to have a developing tail! Recent calculations
give it a period of just over 5 years.
The Shower; -
the comet seems to have
laid down a long narrow stream of dust which we cross almost at right
angles between 0600 - 0800 UT on the
24th May. The meteor
speed is around 40,000 mph and the particles are big by meteor standards
i.e more than 1mm and should produce fireballs. Clearly for us the peak
occurs in daylight, so visual watch should be kept before dawn and then
a radio watch at peak time. The prospects were very promising, however
in the end the maximum was only a few per hour but some were very
spectacular and the timing of the peak was very good.
from Andy Smith comes the new links to the Norman Lockyer Observatory,
and other radio meteor stations
Stellarium image that follows makes it clear that all you have to do to
find the radiant is look at the Pole Star. Again for the UK the best
time is after midnight and before dawn.
Perseid Meteor shower
also known as the August Shower. It is the most reliable and watchable of all. The peak 12th-13th Aug. corresponds with a new Moon and
is very favourable this time. The parent comet is known as Swift-Tuttle
after the astronomers who jointly discovered it. As usual with showers
like this the best numbers are seen after midnight. The two earlier
evenings will also be good.
To hear the meteors
listen to Andy Smith's radio meteor page on http://www.tvcomm.co.uk/radio
He is also running meteorwatch on Twitter so up to the minute reports can
good report from Shetland where Mike saw 40 in a fairly short time. The
link to his report - which incorporates our (Stewart's) images can be
This very reliable shower has a broad peak which covers the
10 -12th August and this year corresponds with a New Moon, some arrive
earlier in the month and some are later than this. Like many showers
this one is best seen after midnight, it also has a fair number of
Fireballs or Bolides. There should be no problem, given clear skies, of
seeing about one meteor every 2 minutes. The parent comet is known as
Swift-Tuttle after the astronomers who discovered it.
worked well for us and our Facebook Page was humming.
The Taurid Meteor Shower;-The second
stream is due now 12th/13th Nov so watch out for fireballs - those
shooting up from the ground are fireworks! (date 2012)
Saturday Nov 3rd was the peak of the Southern Taurid meteor
shower. Already making headlines around the world for producing
fireballs, the Taurids will be best visible in the early morning hours,
but the Moon will interfere. The radiant for this shower is, of course,
the constellation of Taurus and red giant Aldeberan, but did you know
the Taurids are divided into two streams?
It is surmised that the original parent comet shattered as it passed
our Sun around 20,000 to 30,000 years ago. The larger "chunk" continued
orbiting and is known as periodic comet Encke. The remaining debris
field turned into smaller asteroids, meteors and larger fragments that
often pass through our atmosphere creating the astounding "fireballs"
known as bolides. Although the fall rate for this particular shower is
rather low at 7 per hour, these slow travelling meteors (27 km or 17
miles per second) are usually very bright and appear to almost "trundle"
across the sky. With the chances high all week of seeing a bolide, this
makes a bit of quiet contemplation under the stars worthy of a morning
walk. Be sure to look at how close Saturn is to the Moon!
Many thanks to Tammy Plotner of Universetoday.com (29th Oct) for this
The shower has been traced back to the comet Encke named after
Johann Encke who realised that comets seen in previous years were in
fact he same comet with a very short period (3.5 years). He is also
remembered as the director of the Berlin Observatory at the time of the
discovery of the planet Neptune in 1846.
There is a high expectation of small pebbles coming in with the shower
all week. These will give rise to fireballs aka bolides which
sometimes themselves give rise to sonic booms.
The Leonids ;-
The Leonids are happen mid November, a waxing Moon in 2010
will interfere until nearly dawn. About 20+ per hour have been seen. See www.spaceweather.com
for the 18th.
The ZHR is expected to be around 20 this year, nothing special but
good enough to get the kit organised for the bigger showers still to come.
Praesepe is close to the radiant.
eonid meteor shower is produced when the Earth runs through the dust
produced by the comet Tempel-Tuttle when it passes close to the Sun.
Image credit "universetoday" Niagara Falls
Some of the dust
particles are too small to burn up and float to Earth as micrometeorites
some will be held in our "Catch a
Falling Star" project.
Tammy Plotner of Universe
Today had an excellent feature see www.universetoday.com
see categories - meteor showers then the feature for Nov 16th
2009. Also she has an update on UT for the 17th 2010.
If it should be
cloudy the check out Andy Smith radio meteor page www.tv.com.uk
and follow the links to his live meteor page. Norman Lockyer Observatory (S.Devon)
also have a live radio link off his page. For real time images go to Slooh www.slooh.com
for their real time all sky cameras. Australia could be good in our
afternoon. The peak of this shower is around 15.00UT.
John Couch Adams - the 19th cent. Cornish
astronomer, better known for his Neptune work also studied the Leonid meteor
shower in depth.
The woodcut is from my copy of "The Midnight Sky"
1891 by the famous Cornish Astronomer Edwin Dunkin.
John Couch Adams -
the 19th cent. Cornish astronomer, better known for his work on Neptune
also studied the Leonid meteor shower in depth.
The Geminids a shower of mystery;-
Mid Dec.. updated 2014
A great night was had by all with lots of meteors seen flashing at high
speed across a very dark sky (NELM 6.
In mid December the Earth is hit by the largest meteor shower of the
year. However it has not always been like this. The peak, this year, is
expected to be around 80 - 100 per hour. this shower does contain some
good fireballs should the Moon reduce the number of faint meteors seen.
On a clear morning in Cornwall, allsorts of constellations
generally overlooked are clearly visible Corvus is but one example. Geminds
flying about too! Is the sky clearer in the morning than the evening?
In mid (12/14th) December the Earth is hit by the largest
meteor shower of the year. This year we have a New Moon so no problem
there. From a dark sky site lots will be
seen, go with some mates - some you see - some they see! Look to the east
to Gemini no less.
This shower was first noticed by R P Greg in the UK and in the US by Marsh
and Twining in 1862. At that time the number of meteors was about 40 per
hour. As the years went by the number per hour rose steadily to about 55
in 1947 and about 70 through the 50’s by the 90’s it was close
to 80 and this year is estimated to be about 100 or even 120! This is
pretty rare, if not unique, for a major meteor shower. The actual peak is
forecast to be 06.00 GMT on 13 - 14th, pre sunrise which circa 7.30GMT
Meteor showers are caused when the Earth’s atmosphere runs into the
dust trail left behind by a comet. In this case no comet fits the
However Apollo asteroid 3200 Phaethon does. This asteroid was
discovered Oct 11 1983 by John Davis and Simon Green using the Infra
Red Astronomical Satellite IRAS. It is believed that Phaethon used
to be a comet but got captured into an asteroid orbit. It does have a very
eccentric orbit passing very close to the Sun but then traveling right out
to beyond Mars. Orbital period 1.4 years, diameter about 5 kilometers. It
is the close approach to the Sun (0.14 AU) that has caused the comet to be
battered by the heat of the Sun. The dust particles are denser than most
comet dust 2g/cu cm Perseid dust is 0.3 g/cu cm. This
indicates a rocky origin, the Perseid dust is more fluffy.
The increase in meteors per hour as the years go by is caused by the
dust cloud being forced towards the Earth by the gravitational pull of
"When the sky is clear, a bright slow moving Geminid
Fireball crossing the sky is truly one of nature's most awesome sights"
who says so one of the most famous comet and meteor experts
sky is covered with clouds and this is where the radio folk come in;-
The best set of radio meteor detection stations are featured on the
Norman Lockyer site. www.normanlockyer.com Click on Our Society, the
Radio Astronomy Group, - the various stations are listed on the LH
column. Often the peak is preceded and followed by a much broader sub
peak of faint meteors which are best picked by radio detectors.
The Ursids 24th Dec. The
last shower of the year and very few people see it, could it be cloud
and rain or the very low position of the radiant or may be its just
Christmas.To be sure nothing like as dramatic as the Geminds. This shower first
came to the attention when observed by Czech astronomer Antonin Becval
when he noted a big increase in meteor activity on Dec 22nd 1945.
Looking back further it seems to be the same stream that Denning saw
between 1890 and 1910. It was followed again in 1947 and in the years
following. However the rate always seems to be between 11 and 20 per hour.
Where to look? The radiant is close to the two bright
stars in Ursa Minor known as the Guardians. As is known meteor
showers result from the Earth running into the dust left behind by
passing comets. In this case the comet is Comet Tuttle. This is the most
recent meteor shower to be recorded, although the 24th is given as
the peak date Ursids can be seen throughout the second half of
December. NB the radiant is the place in the sky where the meteors appear
to radiate from. It is often said that the best position to adopt to
view these meteors is lie on your back and look north, it is just
possible that in view of the date this could be a fairly
well observed shower - more than the ZHR of circa 15 would indicate. Shakespeare
says of meteors "I shall fall like a bright exhalation in the
evening, and no man see me more" The waning Moon will interfere
most of the night which is a shame. last revised 2012
Paul's new Moon taken
28th March 2009 a Moon this size can been seen in full daylight, however
any smaller and it becomes very hard to locate.
For all of Paul's
images in full resolution see www.zenfolio.com/paulh101
Mercury is always hard
to find However Paul &
I managed to find a good location on April 28th 2009. It was spotted before
setting close to the Pleiades.
Graced our skies between January and March 09, although never as bright as
we would have liked it raised public awareness. Its green colour was due
to the presence of ionised Cyanogen CN and diatomic carbon C2, these ions
can only exist in a plasma form in the near vacuum of space. It had two
tails one facing forward - the dust anti-tail which is rare in addition to
the normal ion tail which showed unusual twists. Paul Hughes our own imager
took the first photograph of the comet in the UK.
M42 a long time favourite
with astronomers Paul used a DSLR and stacked a number of images.
For all of
Paul's images in full resolution see www.zenfolio.com/paulh101
Partial Solar Eclipse
1st Aug 08 - showing media interest!
Radio Cornwall with
Louise Midgley in the Activity Room.
Images by Robb Stidson of our imaging team
LUNAR ECLIPSE 3rd MARCH 2007 - CORNWALL
This eclipse proved one of the best for many years.
Images by Paul Hughes of the Observatory.
members had a very good evening..
The images have been removed but check www.spaceweather.com
and the archive file.
SOLAR ECLIPSE TURKEY
2006 MARCH 29TH
This was the best solar eclipse for a number of years and
one we were not going to miss!
Brian Sheen and Allan Ridgeley therefore approached Cosmos
Holidays and offered their services as Package Tour Astronomers. A few
days in smart hotels looking at suitable locations in Turkey and all was
ready. The day dawned bright and clear, 350 expectant astronomers gathered
at a five star hotel that was closed for a few days. The images that
follow capture just a taste of the excitement.
copyright Andrew Holt for details contact the
Cornish Astronomer Secures The Prime Meridian of The World for
Britain In 1884
An article by Brian Sheen
A hundred and twenty years ago a triumphant John Couch Adams returned
to Britain after difficult month in America. It had been clear for some
while that the worlds shipping was in difficulty as the charts in use were
based on a variety of Prime Meridians. The Americans called a Conference
in Washington to resolve the situation. Britain's principal delegate was
Couch Adams as Director of the Cambridge Observatory........More
The Transits of Venus
A talk given to club members by Brian Sheen.
The principal characteristic of the solar system is that it is
co-planar, all the planets and the Sun lie within a few degrees of one
another. This means that the Inferior planets, Mercury and Venus can pass
across the face of the Sun this phenomena is known as a transit. Mercury
transited in May 2003. Venus has not crossed the Sun since 1882, and will
not do so again until 2012. The intervals between transits are
successively 8, 121.5, 8, 105.5, 8, 121.5 et seq. As can be seen they
occur in pairs and these pairs alternate between June and December events.
The study of transits has covered nearly 400 years and during this time a
number of very significant changes have taken place......More
This has been deleted, it is now dated and we
need the space! More
Mars Past, Present & Future.
The word Planet comes from the Greek meaning "Wandering
Star". Of all the planets in the sky Mars is the one to which this
term applies the most. Because it has such a strange motion it has been
studied for thousands of years, although until the arrival of the
telescope with little effect. At its best only Venus can be brighter, as a
red object Mars stands alone, the Romans naming it after the god of war,
the rate at which it travels east, it brightness variations even at
opposition attracted much attention from the astronomers of old......More
Just a Minute- What's all this about Time?
astronomers we get involved in three basic types of time. These are......More
Light Pollution in Cornwall
There are several areas of light pollution that could be
investigated but my main objective will be to discover if and how much the
night sky around the St Austell area has been affected by street and
industry lighting. I have
chosen the night sky because as an amateur astronomer the subject is close
to heart and the thought of losing the stars to light pollution would be
unacceptable. St Austell is
set in a rural area, which should mean there are areas where the stars are
visible and where the sight in more populated areas are not.
My biggest concern is with the increasing population and the
building of estates, the areas where observing is possible will become
less available as time goes on......More
Telescope Buyers Guide
Amateur Astronomy is one of the most fascinating
hobbies in the world, but to get really into it, you probably will want to
get a telescope. But to read the adverts in the magazines, you've got one
very confusing choice out there. As well as the type of scope be it a
Reflector, Refractor or a Catadioptic - don't worry at this point, we'll
explain the differences later- there are many different sizes and even
some which we wouldn't even poke a stick at. Finally there's the decision
as to how much to spend. This article has been compiled by the
membership's own experiences. They all had to buy that 'first telescope',
and hopefully, you can benefit from their hindsight. We'll help answer
many of the questions you may have about purchasing a telescope as well as
clearing up some of the mysteries about astronomical telescopes in
Global Warming- The State of Play
That there have been changes in the world's climate within living
memory is indisputable. It is just the weight placed by the various
authorities on the different elements that cause these changes that is
questioned by some......More
As a follow up to the 1999 eclipse experiment, a small group went to
Zambia to measure visible light and infrared flux changes during the
eclipse using photosensitive diodes. The experiment was carried out
successfully but the anomalous result recorded during the 1999 eclipse was
not repeated. A report was published in 'Astronomy and
Geophysics' June 2003.
Both the direct and indirect energies were measured throughout the
eclipse, using detector arrays made at Roseland and Rutherford. The
changes in energy levels followed what was expected from the geometry of
the Sun Moon system and did not repeat the sudden drops recorded during
the 99 eclipse in Cornwall.
However random fluctuations were noted and these are assumed to be due
to the effect of atmospheric scattering. These are probably the same
fluctuations that give rise to the Shadow Bands seen prior to totality. We
hope to repeat the experiments routinely in Cornwall to give a measure of
atmospheric variation. It is believed that this is the first time that
these observations have been carried out in this way.
|Brian Sheen with Val White (centre) who will be
helping with the experiments over the coming summer
During 2003, a balloon was to be launched from the
Coast of Cornwall to the edge of space, 40km high. As the balloon was going
into the area where micrometeorites are found our observatory built a
package for the balloon to collect these onto a self adhesive substrate.
After the balloon has landed in the Atlantic, the collecting plates will
be cleaned of the micrometeorites and they will then be examined under a
scanning electron microscope.
||From left to right- Alan Ridgley (The Roseland Observatories
Technical Advisor), Colin Prescot (Qinetiq Pilot and CEO), Andy
Elson ( Qinetiq Pilot and Project Director) and our very own Brian
Sheen (Roseland Observatory Director)
In the event the balloon was damaged on the deck of the launch ship
and never got beyond being half inflated. As the TV interviewer said
"Brian we have a problem!"