Archive for May, 2010

Our spring almanac 28.05.2010 – 03.06.2010

Posted in astronomical time on May 28, 2010 by espacelab

Night skies in Auriga



Messier 38 is an open cluster in the Auriga constellation.
It was discovered by Giovanni Batista Hodierna before 1654 and independently found by Le Gentil in 1749. The cluster’s brightest stars form a pattern resembling the Greek letter Pi.


Capella
Capella (α Aurigae / α Aur / Alpha Aurigae / Alpha Aur) is the brightest star in the constellation Auriga, the sixth brightest star in the night sky and the third brightest star in the northern celestial hemisphere, after Arcturus and Vega. Although it appears to be a single star to the naked eye, it is actually a star system of four stars in two binary pairs. The first pair consists of two bright, large type-G giant stars, both with a radius around 10 times the Sun’s, in close orbit around each other. These two stars are thought to be cooling and expanding on their way to becoming red giants. The second pair, around 10,000 astronomical units from the first, consists of two faint, small and relatively cool red dwarfs. The Capella system is relatively close, at only 42.2 light-years (12.9 pc) from Earth.

Little female goat
The name Capella means small female goat from Latin Capra. In Roman mythology, the star represented the goat Amalthea that suckled Jupiter.

It was this goat whose horn, after accidentally being broken off by Jupiter, was transformed into the Cornucopia, or “horn of plenty”, which would be filled with whatever its owner desired.


Su Song Star Map
In traditional Chinese astronomy, Capella was part of the asterism 五車; Wŭ chē; English: Five Chariots, which consisted of Capella together with β, ι, and θ Aurigae, as well as β Tauri.





Since it was the second star in this asterism, it has the name 五車二; Wŭ chē èr; English: Second of the Five Chariots. This five-star Chinese constellation contains Auriga plus Beta Tauri.

In Australian Aboriginal mythology for the Booroung people of Victoria, Capella was Purra, the kangaroo, pursued and killed by the nearby Gemini twins, Yurree (Castor) and Wanjel (Pollux).

Su Song and his water clock
In ancient China water powered astronomical clocks were the marvel of the age. In the year 1086, the boy emperor of China ordered the construction of an astronomical clock that should surpass all others. He chose a man called Su Song to design and build a magnificent tower and water driven mechanism to make an astronomical timekeeper. As illustrated above, Su Song completed a large celestial atlas of several star maps, several terrestrial maps, as well as a treatise on pharmacology. The latter discussed related subjects on mineralogy, zoology, botany, and metallurgy. So Su Song (simplified Chinese: 苏颂; traditional Chinese: 蘇頌; pinyin: Sū Sòng; style name: Zirong 子容) (1020–1101 AD) was a renowned Chinese statesman, astronomer, cartographer, horologist, pharmacologist, mineralogist, zoologist, botanist, mechanical and architectural engineer, poet, antiquarian, and ambassador of the Song Dynasty (960–1279).

Su Song engineered the construction of this a water-driven astronomical clock tower in medieval Kaifeng, using a design which employed the use of an early escapement mechanism. The escapement mechanism of Su’s clock tower had previously been invented by Buddhist monk Yi Xing and government official Liang Lingzan in 725 AD to operate a water-powered armillary sphere, although Su’s armillary sphere was the first to be provided with a mechanical clock drive. Su’s clock tower also featured the oldest known endless power-transmitting chain drive, called the tian ti (天梯), or “celestial ladder”, as depicted in his horological treatise. The clock tower had 133 different clock jacks to indicate and sound the hours.

On the top of the tower he installed an instrument called an armillary sphere that represented the paths of the Sun, the Moon and some important stars, as they crossed the sky. On the floor below, he designed a demonstrational celestial globe to show all the important heavenly objects. These instruments were moved round by a pair of vertical transmission shafts that were regulated by the pouring of water into small buckets on a giant wheel. The weight of the water in the buckets turned the wheel the distance of a spoke every 24 seconds. This wheel was powered to drive a number of connected wheels, stacked up in the lower half of the tower to show the hours, the quarter of the hours and the 24 second intervals of the main mechanism.

The Armillary Sphere

Basically, an armillary sphere is a a model of the celestial sphere used in astronomy and navigation. The celestial sphere is an imaginary sphere, concentric with the Earth and rotating upon the same axis. All objects in the sky can be thought of as projected upon the celestial sphere.

Armillary spheres were developed by the Greeks and were used as teaching tools already in the 3rd century B.C. Throughout Chinese history, astronomers have created celestial globes (simplified Chinese: 浑象) to assist the observation of the stars. The main purpose for using the armillary sphere in Chinese astronomy was in working out calculations for the lunisolar (moon+sun) calendar.

May 30 Trinity Sunday
On the first Sunday after Pentecost Christians meditate on the nature of God as “Three in one”. The Christian doctrine of the Trinity teaches the unity of Father, Son, and Holy Spirit as three persons in one Godhead. This can be difficult to understand, but in theology, monotheism, that is the belief that only one God exists, may still include concepts of a the many and the one of the divine. Additionally, most Christian churches teach Jesus to be two natures both divine and human. This concept of “monotheism” links the Abrahamic (coming from Abraham) religions of Judaism, Christianity and Islam.

A vision of St Augustine
Augustine of Hippo (November 13, 354 – August 28, 430), Bishop of Hippo Regius, was a Latin speaking philosopher and theologian living in the Roman Africa Province. When the Roman Empire in the West was starting to disintegrate, Augustine developed the concept of the Church as a spiritual City of God distinct from Earthly Cities. His thought profoundly influenced ideas during the middle ages and in to the modern world, because Augustine’s City of God was closely identified with the church, the community which worshipped God.

Pictures of St Augustine’s life increase steadily in number from the middle ages, becoming very frequent in the eighteenth century. The main events of his life are depicted: his early life ; his conversion; his baptism; the vision of the child on the seashore. This last legend was abundantly illustrated.

A child, often portrayed as an angel, appeared to the saint who was meditating on the mystery of the Trinity whilst the child is shown trying to empty the sea with a shell, when Augustine tells the child that this was impossible, the child replies that Augustine was also engaged on the equally impossible task of explaining the Trinity.

June 1 is International Children’s Day
It is half-term for many schools in Basingstoke this week, so there is ample opportunity for you to enjoy this day. The World Conference for the Well-being of Children in Geneva, Switzerland proclaimed June 1 to be International Children’s Day in 1925. It is not clear as to why June 1 was chosen as the International Children’s Day: one theory has it that the Chinese consul-general in San Francisco (USA) gathered a number of Chinese orphans to celebrate the Dragon Boat Festival in 1925, which happened to be on June 1 that year, and also coincided with the conference in Geneva.

This year the festival takes place on 16 June 2010.

June 3 Corpus Christi
This is the day that Roman Catholics celebrate the “real presence of Christ in the Eucharist”. The festival falls on the Thursday after Trinity Sunday. The appearance of Corpus Christi as a feast in the Christian calendar was primarily due to the petitions of the thirteenth-century Augustinian nun Juliana of Liège. From her early youth Juliana had a veneration for the Blessed Sacrament, and always longed for a special feast in its honour. This desire is said to have been increased by a vision of the Church under the appearance of the full moon having one dark spot, which signified the absence of such a solemnity.

In 1208 she had her first vision of Christ in which she was instructed to plead for the institution of the feast of Corpus Christi. The vision was repeated for the next 20 years but she kept it a secret. When she eventually told her confessor, he told the bishop.

The Walled Garden Down Grange 03.05.2010

Our spring almanac 21.05.2010 – 27.05.2010

Posted in astronomical time on May 21, 2010 by espacelab

Shuttle mission continues at the ISS

The Atlantis Space Shuttle Astronauts are still working on the International Space Station.

Ten years ago, whilst the first astroclock project was under way during the year 2000, the ISS became permanently habitable with the installation of the station’s service module. This provides the main living quarters for resident crews, environmental systems and attitude & orbit control. The module also provides docking locations for Soyuz spacecraft, Progress spacecraft and the Automated Transfer Vehicle.

A famous deep sky object in Orion
Looking deep into Winklebury School’s constellation of Orion the Hubble telescope shows us one of the most beautiful astronomical views in our galaxy.

The Horsehead Nebula (also known as Barnard 33 in bright nebula IC 434) is a dark nebula in the constellation Orion, part of the much larger Orion Molecular Cloud Complex. It is approximately 1500 light years from Earth. It is one of the most identifiable nebulae because of the shape of its swirling cloud of dark dust and gases, which is similar to that of a horse’s head.

The shape was first noticed in 1888 by Williamina Fleming at the Harvard College Observatory. The red glow originates from hydrogen gas behind the nebula, ionized by the nearby bright star Sigma Orionis. The darkness of the Horsehead is caused mostly by thick dust, although the lower part of the Horsehead’s neck casts a shadow to the left. Streams of gas leaving the nebula are funneled by a strong magnetic field. Bright spots in the Horsehead Nebula’s base are young stars just in the process of forming.


The bright stars of Orion

Betelgeuse is a massive M-type red supergiant star nearing the end of its life. When it explodes it will even be visible during the day. It is the second brightest star in Orion, and is a semiregular variable star. It serves as the “right shoulder” of the hunter it represents and is the twelfth brightest star in the night sky.

Rigel, which is also known as Beta Orionis, is a B-type blue supergiant that is the sixth brightest star in the night sky. Similar to Betelguese, Rigel is fusing heavy elements in its core and will pass its supergiant stage soon, either collapsing in the case of a supernova or shedding its outer layers and turning into a white dwarf. It serves as the left foot of Orion, the hunter.

Bellatrix was designated Gamma Orionis by Johann Bayer, but is known colloquially as the “Amazon Star;” it is the twenty-second brightest star in the night sky. Bellatrix is considered a B-type blue giant, though it is too small to explode in a supernova. Bellatrix’s luminosity is derived from its high temperature rather than its radius. Bellatrix serves as Orion’s left shoulder.

Mintaka garnered the name Delta Orionis from Bayer, even though it is the faintest of the three stars in Orion’s Belt. It is a multiple star system, composed of a large B-type blue giant and a more massive O-type white star. The Mintaka system is an eclipsing binary variable star, where the eclipse of one star over the other creates a dip in brightness. Mintaka is the westernmost of the three stars in Orion’s Belt.

Alnilam was named Epsilon Orionis, a consequence of Bayer’s wish to name the three stars in Orion’s Belt (from north to south) in alphabetical order. Alnilam is a B-type blue supergiant, despite being nearly twice as far from the Sun as Mintaka and Alnitak, the other two belt stars, its luminosity makes it nearly equal in magnitude.

Alnitak was designated Zeta Orionis by Bayer, and is the easternmost star in Orion’s Belt. It is a triple star some 800 light years distant, with the primary star being a hot blue supergiant and the brightest class O star in the night sky.

Saiph was designated Kappa Orionis by Bayer, and serves as Orion’s right foot. It is of a similar distance and size to Rigel, but appears much fainter, as its hot surface temperature causes it to emit most of its light in the ultraviolet region of the spectrum.

Orion’s navigational stars
Betelgeuse, Rigel and Bellatrix are among the navigational stars.

Navigation by stars and birds
Polynesian navigation was a system of navigation used by Polynesians who have lived on the opposite side of the Earth from where we live for thousands of years. They found out how to make long voyages across thousands of miles of open ocean in the Pacific, traveling to small inhabited islands using only their own senses and knowledge passed down through the generations by oral tradition from navigator to apprentice, often in the form of song.

In order to locate directions at various times of day and year, navigators in Eastern Polynesia memorized important facts: the motion of specific stars, and where they would rise and set on the horizon of the ocean; weather; times of travel; wildlife species which come together at certain times and places; directions of swells on the ocean, and how the crew would feel their motion; colors of the sea and sky, especially how clouds would cluster at the locations of some islands; and angles for approaching harbors.

Scientists think that long-distance Polynesian voyaging followed the seasonal paths of birds. There are some references in their oral traditions to the flight of birds and some say that there were range marks onshore pointing to distant islands in line with these flyways.

The peoples of the Pacific, including Micronesians and Polynesians, developed navigating by the stars into a fine art. Polynesians imagined the heavens as the interior of a dome where a star proceeded along a path which passed over certain islands. They had names for over a hundred and fifty stars. A navigator would have known where and when a given star rose and set, as well as which islands it passed directly over. They would have then been able to sail toward the star they knew to be over their destination, and as it moved westward with time they would then set their course by the succeeding star which would have then moved over the target island.

Bird migration and navigation
It is not just human beings that navigate using astronomical observation and a sense of time. Birds, the descendants of dinosaurs, have been doing this for millions of years. The earliest recorded observations of bird migration were 3000 years ago, as noted by Hesiod, Homer, Herodotus, Aristotle and others. The Bible also notes migrations, as in the Book of Job (39:26), where the inquiry is made: “Doth the hawk fly by Thy wisdom and stretch her wings toward the south?” The author of Jeremiah (8:7) wrote: “The stork in the heavens knoweth her appointed time; and the turtledove, and the crane, and the swallow, observe the time of their coming.”

Aristotle noted that cranes traveled from the steppes of Scythia to marshes at the headwaters of the Nile.

Pliny the Elder, in his Historia Naturalis, repeats Aristotle’s observations. Aristotle however suggested that swallows and other birds hibernated. This belief persisted as late as 1878, when Elliott Coues listed the titles of no less than 182 papers dealing with the hibernation of swallows. It was not until early in the nineteenth century that migration as an explanation for the winter disappearance of birds from northern climes was accepted.

The primary physiological cue for migration are the changes in the day length. These changes, which are all to do with the seasons and the path of the sun in the sky, are also related to hormonal changes in the birds.

Navigation is based on a variety of senses. Many birds have been shown to use a sun compass. Using the sun for direction involves the need for making compensation based on the time. Navigation has also been shown to be based on a combination of other abilities including the ability to detect magnetic fields (magnetoception), use visual landmarks as well as their sense of smell (olfactory cues).

May 23 Pentecost

Pentecost takes place on the seventh Sunday after Easter, commemorating the descent of the Holy Spirit upon the disciples and the birth of the Christian Church.

The first Pentecost
Pentecost comes from a Jewish harvest festival called Shavuot (see previous post).
The apostles were celebrating this festival when the Holy Spirit descended on them. It sounded like a very strong wind, and it looked like tongues of fire. The apostles then found themselves speaking in foreign languages, inspired by the Holy Spirit. People passing by at first thought that they must be drunk, but the apostle Peter told the crowd that the apostles were full of the Holy Spirit.

May 23 is also celebrated as the birthday of Guru Amar Das (Nanakshahi calendar). Guru Amar Das (1479-1574) was the third of the Sikh Gurus.

Atlantis Shuttle landing 26 May
The Atlantis shuttle landed at the Kennedy Space Center after what looks to have been its final mission. The vehicle touched down on runway 33 at the Florida spaceport at 0848 local time (1248 GMT).

Atlantis, with its six-person crew, has just delivered a Russian mini-module and spare equipment to the International Space Station (ISS). The orbiters are due to be retired this year, and just two more outings are planned – for Discovery and Endeavour.

May 27 Wesak, Vesākha or Buddha day
The most important of the Buddhist festivals. It celebrates the Buddha’s birthday, and, for some Buddhists, also marks his enlightenment and death.

Queen Maya riding horse carriage retreating to Lumbini to give birth to Prince Siddhartha Gautama.

Prince Siddhartha Gautama become an ascetic hermit.
Vesākha (Pali; Sanskrit: Vaiśākha वैशाख) is an annual holiday observed traditionally by Buddhists in the Indian subcontinent and South East Asian countries of Singapore, Vietnam, Thailand, Cambodia, Malaysia, Myanmar, and Indonesia. Sometimes informally called “Buddha’s Birthday,” it actually encompasses the birth, enlightenment (nirvāɳa), and passing away (Parinirvāna) of Gautama Buddha.

A Vesak pandol or torana in Colombo, Sri Lanka.
The exact date of Vesākha varies according to the various lunar calendars used in different traditions. In Theravada countries following the Buddhist calendar, it falls on the full moon Uposatha day (typically the 5th or 6th lunar month). Vesākha Day in China is on the eighth of the fourth month in the Chinese lunar calendar. The date varies from year to year in the Western Gregorian calendar but falls in April or May. In 2010 the first full moon day is 27 May.

Buddhism
Buddhism is a religion and philosophy encompassing a variety of traditions, beliefs and practices, largely based on teachings attributed to Siddhartha Gautama, commonly known as the Buddha (Pāli/Sanskrit “the awakened one”). The Buddha lived and taught in the northeastern Indian subcontinent sometime between the 6th and 4th centuries BCE. Estimates of the number of Buddhist followers in the world today range from 230 million to 500 million, with most around 350 million, making Buddhists the 4th largest religious group in the world. Not all traditions of Buddhism share the same philosophical outlook, but all accept the Buddha as their teacher. Buddhists generally classify themselves as belonging to one of the main schools of buddhism, either the Theravada school or the Mahayana school.


Winklebury 27.05.2010

Our spring almanac 14.05.2010 – 20.05.2010

Posted in Uncategorized on May 14, 2010 by espacelab



One Swallow does not make a summer

One swallow does not make a summer, nor does one day; and so too one day, or a short time, does not make a man blessed and happy. So said the Greek philosopher and scientist Aristotle.

The Barn Swallow migrates from Africa to spend the spring and summer here in southern England. Migration of Barn Swallows between Britain and South Africa was first established on 23 December 1912 when a bird that had been ringed by James Masefield at a nest in Staffordshire, was found in Natal nearly 6000 miles from here. For people living in South Africa the month of May is not a month for looking forward to summer, winter is coming, which is probably good for the national football teams training for the World Cup. In southern Africa, which is in the southern hemisphere of our planet, the seasons are the opposite of the ones we have here. During May, June and July, the northern hemisphere is exposed to more direct sunlight because the hemisphere faces the sun. The same is true of the southern hemisphere in November, December and January.

It is the tilt of the Earth that causes the Sun to be higher in the sky during the summer months which increases the solar flux. However, due to seasonal lag, June, July and August are the hottest months in the northern hemisphere and December, January and February are the hottest months in the southern hemisphere.

Morgaston Woods
Swallows usually appear in April, but this year have only become more noticeable as we move into the middle of May. This year most of the signs of spring have been late, all catching up during this month of May. The appearance of bluebells and daisies for instance.

Canis Major



Canis Major has a deep sky object in Messier 41 (also known as M41 or NGC 2287). It is an open cluster discovered by Giovanni Batista Hodierna before 1654 and was perhaps known to Aristotle about 325 BC.

M41 lies about four degrees almost exactly south of Sirius. It contains about 100 stars including several red giants, the brightest being a spectral type K3 giant near the cluster’s center. A Red Giant is a luminous giant star of low or intermediate mass (roughly 0.5–10 solar masses) in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius immense and the surface temperature low, somewhere from 5,000 K and lower. The appearance of the red giant is from yellow orange to red, including the spectral types K and M, but also class S stars and most carbon stars.

At some point in the Sun’s future evolution it will become a Red Giant.

Sirius
Sirius is the brightest star in the night sky of earth. With a visual apparent magnitude of −1.46, it is almost twice as bright as Canopus, the next brightest star. The name “Sirius” is derived from the Ancient Greek Seirios (“scorcher”).

What is visible to the naked eye as a single star is actually a binary star system, consisting of a white main sequence star of spectral type A1V, termed Sirius A, and a faint white dwarf companion of spectral type DA2, termed Sirius B.


Sirius is also known colloquially as the “Dog Star”, reflecting its prominence in its constellation, Canis Major (English: Big Dog). The heliacal rising of Sirius marked the flooding of the Nile in Ancient Egypt and the “Dog Days” of summer for the Ancient Greeks, while to the Polynesians it marked winter and was an important star for navigation around the Pacific Ocean.

Navigation by the stars

Sirius, being the brightest star, is one of the so called navigational stars used in celestial navigation. Celestial navigation, also known as astronavigation, is a position fixing technique that has steadily evolved over several thousand years to help sailors cross featureless oceans without having to rely on estimated calculations, or dead reckoning, to enable them to know their position on the ocean. Celestial navigation uses “sights,” or angular measurements taken between a visible celestial body (the sun, the moon, a planet or a star) and the visible horizon.

The angle measured between the sun and the visible horizon is most commonly used. Skilled navigators can additionally use the moon, a planet or one of 57 navigational stars whose coordinates are tabulated in the Nautical Almanac and Air Almanacs. Seafarers have used these stars through the ages, so the list of 57 stars that navigators use comes to us through the practice of their skills over thousands of years.

Nautical Almanac

A nautical almanac is a publication describing the positions of a selection of celestial bodies for the purpose of enabling navigators to use celestial navigation to determine the position of their ship while at sea. The Almanac specifies for each whole hour of the year the position on the Earth’s surface (in declination and Greenwich hour angle) at which the sun, moon, planets and first point of Aries is directly overhead. The positions of 57 selected stars are specified relative to the first point of Aries.

Prior to the introduction of electronic means of navigation the only way to fix an aircraft’s position at night was by taking star sights using a sextant in the same manner as that used by marine navigators on board ships.

To do this requires a 360-degree view of the horizon and the astrodome was devised to allow an uninterrupted view of the sky from horizon to horizon. Hence the astrodome is a hemispherical transparent dome fitted in the cabin roof of an aircraft for the purpose of allowing the use of a sextant during astro-navigation.

Shavuot
The Jewish festival of Shavuot is also known as the festival or feast of ‘Weeks’. There is no set date for the two-day festival, but it takes place seven weeks (fifty days) after the first day of the spring festival of Passover which falls this year on May 19. This also marks the start of the wheat harvest and the end of the barley harvest.


High places
Shavuot marks the time that the Jews received the Torah on Mount Sinai. It is considered a highly important historical event. The tablets of stone inscribed with the 10 Commandments were, according to traditional teachings of Judaism in the Talmud, made of blue sapphire stone as a symbolic reminder of the sky, the heavens, and ultimately of God’s throne.

The Christian festival of Pentecost also comes from Shavuot. St Catherine’s Monastery at the foot of Mt. Sinai is one of the oldest surviving Christian communities.

Prayers are said on Shavuot (especially at dawn) to thank God for the five books of Moses (collectively known as the Torah) and for his law. Some people also spend the first night of Shavuot studying the Torah. Synagogues are decorated with flowers and plants on this joyous occasion to remember the flowers of Mount Sinai. Dairy products are also eaten during Shavuot. There are many interpretations about why this custom is observed. It is believed that once the rules about the preparation of meat were revealed in the Torah, the people of Sinai were reluctant to eat meat until they fully understood the rules.


Ascension
In the last post we included Ascension Day that marks the last earthly appearance of Christ after his resurrection celebrated 40 days after Easter. The Catholic Church in England and Wales celebrates it on the following Sunday 16 May instead.


Final ascent
On May 14, 2010 the Space Shuttle Atlantis lifted off into space for its final voyage during which it will visit the International Space Station.

19.05.2010
Two spacewalking astronauts began a tricky battery swap on the space station’s solar arrays Wednesday, a job that is expected to take two full spacewalks to complete.

Atlantis mission specialists Michael Good and Stephen Bowen got ahead of schedule, successfully installing more than half of the new batteries. In addition, they were able to fix a snagged cable that was plaguing a sensor camera on shuttle Atlantis and tighten the connection between a stuck antenna and its stand.


South View 20.05.2010

Our spring almanac 07.05.2010 – 13.05.2010

Posted in astronomical time on May 7, 2010 by espacelab

Astroclock sequence of Schools and Constellations
This is the 19th seven day post of our spring almanac and so begins the second sequence of the Basingstoke based Astroclock Junior and Primary School astronomical posts.


The Man Who Drives the Great Cart
The constellation of Bootes is very prominent now, with its bright star Arcturus becoming very noticeable. No wonder it has been associated with myth and folklore, as well as being associated with this time of the year. The Romans called Bootes the Herdsman of the Septemtriones, the seven oxen, which are represented by the seven stars of the Great Cart, known to us as the Plough. The ancient Sumerians called the constellation Riv-but-sane, the Man Who Drives the Great Cart, clearly identifying a similar image-pattern to the Romans. Bootes is also associated with the ploughing of the fields in spring.

Arcturus is the third brightest star in the night sky, after Sirius and Canopus. It is, however, fainter than the combined light of the two main components of Alpha Centauri, which are too close together for the eye to resolve as separate sources of light, making Arcturus appear to be the fourth brightest. It is the second brightest star visible from northern latitudes and the brightest star in the northern celestial hemisphere. The star is in the Local Interstellar Cloud. An easy way to find Arcturus is to follow the arc of the handle of the Plough. By continuing in this path, one can find Spica (α Virginis) as well—hence the maxim, “Arc to Arcturus, then speed on to Spica.”


Arcturus is so bright partly because it is relatively close to the Solar System, being a mere 34 light years in distance, or just over 200 trillion miles, and also because of its size. The diameter of Arcturus is about 25 times that of our Sun, being about 22 million miles across.

Arcturus means in ancient Greek ‘bear watcher’, as we have noted before in our Astrofact files, because of its relative position to the constellation of the Great Bear. So stories connecting the constellation Bootes with Ursa Major seem quite natural, and like Ursa Major Bootes is one of the oldest of the constellations people have identified over thousands of years.

Chinese astronomy
In Chinese astronomy, Arcturus is called Da Jiao (大角, Great Horn, Pinyin: Dàjiǎo), because it is the brightest star in the Chinese constellation called Jiao Xiu. Chinese constellations come from the way the ancient Chinese grouped the stars. They are very different from the modern IAU recognized constellations. This is due to the independent development of ancient Chinese astronomy.

Ancient Chinese skywatchers divided their night sky into 31 regions, namely the Three Enclosures (三垣 sān yuán) and Twenty-eight Mansions (二十八宿 èrshíbā xiù). The Three Enclosures occupy the area close to the North Celestial Pole. The stars in the Three Enclosures can be seen all year around.
The Twenty-eight Mansions occupy the zodiacal band. They can be considered as the equivalent to the 12 zodiacal constellations in the Western Astronomy. In contrast to Western astronomy, the Twenty-eight Mansions reflect the movement of the Moon in a lunar month rather than the Sun in a solar year.

Names of the Months
In this 7 day period we are in the month of May. The name for the month of May comes from the name of the Roman goddess of growth and increase, Maia. All the 12 months of the modern calendar year still have their Roman names, and the establishment of twelve months certainly echoes the lunar cycle over a solar year. So our modern calendar has lots of ancient lore about it, however modern everyday life appears to be.

One attempt to change the names of the months in Europe happened in France just after the French Revolution of 1789. The revolutionary idea was to institute a new calendar, beginning from the ‘first year of liberty’. This was the ‘Calendar of Reason’, introduced in 1792 or Year One. It had uniform months of 30 days each with the extra 5 or 6 days reserved for holidays called Virtue, Genius, Labour, Opinion and Recompense. The new months were named and organized as follows:

Vendemaire (vintage) September 22 – October 21

Brumaire (mist) October 22 – November 20

Frimaire (frost) November 21 – December 20

Nivose (snow) December 21 – January 19

Pluvoise (rain) January 20 – February 18

Ventose (wind) February 19 – March 20

Germinal (seedtime) March 21 – April 19

Floreal (blossom) April 20 – May 19
We will add images to the months below as we go through the rest of the year.
Prairial (meadow) May 20 – June 18
Messidor (harvest) June 19 – July 18
Thermidor (heat) July 19 – August 17
Fructidor (fruits) August18 – September 16

Changing the names of the months may have been revolutionary, but the author of these changes, Philippe-Francois Nazaire Fabre d’Eglantine, seems to have chosen a more traditional, poetic and natural set of images, seasonal images of weather, growth and agricultural labour.


Ascension Day
May 13 is Ascension Day. Ascension Day marks the last earthly appearance of Christ after his resurrection. Christians believe Christ ascended into heaven. It is celebrated 40 days after Easter.


All Saints Church in Fairfields 13.05.2010