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



Ole Romer




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 1610.

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 Scientific Bio

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 Page 76

"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 2014.

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. www.astronomyweek.org.uk the 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 2011.


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 Hanlon 2001

A picture of Romer with his Transit Instrument A5 size a history of astronomy by Charles-Albert Reichen



M82;- A new 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 done Stewart!


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;-

Hi Brian,

Here 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 2016.
















"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.

GCSE Results;- Congratulations 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

Monty’s interviews

     The Stargazing LIVE interview for Radio Cornwall. https://soundcloud.com/simon-rix-1

  The ITV Westcountry News interview at the Observatory. http://www.itv.com/news/westcountry/update/2013-02-01/cornish-boy-reaches-for-the-stars/?&fb_action_ids=10152461740235408&fb_action_types=og.recommends&fb_aggregation_id=288381481237582&fb_source=aggregation

Stargazing LIVE;-  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.



During Stargazing LIVE Mission Control was controlling a Mars Rover that actually was in Mossbank Village Hall in the Shetlands, some of our visitors were able to drive it too.

Link to the Youtube video https://www.youtube.com/watch?feature=player_embedded&v=RhsBJrDkkj8

 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

 broadcasting astronomer.
 Pinner, Nineteen Twenty Four,*
 survived as wartime bomber.


 Fiancée killed, flame carried,
 plainly it was not to be,

 result, he never married,
 ‘Second best, n
o good to me’.

Became opponent of war,
made Moon Maps; ‘Sky at Night’,

which on BBC we saw,
before ‘Sputnik’ satellite.

A ‘Monster Raving Looney’,
pianist while Einstein fiddled.
Musician extraord’nary,
celestial ‘scopes twiddle.                                                    Patrick on his visit to the Observatory several  years ago.
                                                                                                              Image credit Paul Hughes     

© David Youlden, (DaaveRaave)
11/12/2012 11:29
Devington Hall, Truro

David is an old friend of mine from our lab days. He is a regular contributor to community radio. His 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 order.

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 ago.


 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 Tub"! There could well be a second surge before dawn as the Earth drives into the dust particles. Check out 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 http://www.tvcomm.co.uk/radio  Although the peak is now past the rearguard may be seen on any clear night for a few more days.


image from Universe Today


.  Camelopardalids;-  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.

Radio meteors;- from Andy Smith comes the new links to the Norman Lockyer Observatory, and other radio meteor stations

http://www.merriott-astro.co.uk/spam.htm and also http://www.merriott-astro.co.uk/spam2D.htm  i

 The 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.


Image credit Universe Today

Perseid Meteor shower is 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 be obtained. 

2013;- Had a 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 found here;- http://www.macastrofix.info/?q=node/40http:// 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.  Twitter 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 information.               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. See http://www.arm.ac.uk/leonid/  Praesepe is close to the radiant.

  The Leonid 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 1833

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

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 bill. 

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 Jupiter.

 "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 David Levy.

Radio meteors;- Often the 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. 





Comet Lulin   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 Paul                                       Louise Midgley in the Activity Room.

  Images by Robb Stidson of our imaging team



  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.


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 observatory.

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?

As 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 general.....More.

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


Research Projects

1999 Eclipse

  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.

Results Update 

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!" 

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