Saturday, 4 July 2020

Astrognome A-Z of Constellations # 69 Pyxis

Pyxis the Compass
The smallest and least impressive of the four parts into which the constellation Argo Navis the ship was divided into in the 1750s by Lacaille. The other sections Carina, Puppis and Vela.
There are no objects of particular interest to users of binoculars despite the fact that the constellation lies in the Milky Way.
The brightest star and only one above mag 4.0 is alpha at mag 3.7 which is a B1 giant with a surface temperature of 22,000’C and is 880 light years away.
T Pyx is a recurrent Nova that has erupted more times than any other Nova. T Corona Borealis is referred to as the Blaze Star because it became much brighter. T Pyx erupted in 1890, 1902, 1920, 1944, 1960 and 2011. It lies between beta and lambda. At its brightest it has reached the 6th magnitude.

Friday, 3 July 2020

Astrognome A-Z of Constellations # 68 Puppis

Puppis the Stern
This is the largest of the four sections into which the ancient constellation of Argo Navis, the ship of the Argonauts, the constellation was dismembered in the 1750s by the French astronomer Nicolas Lacaille. The other sections are Carina the Keel, Pyxis the compass and Vela the sails.
Puppis lies in the Milky Way and contains rich star fields for sweeping binoculars.
Zeta the brightest star whose name is Naos which means ‘ship’ has a magnitude of 2.2 with a surface temperature of a whopping 38,000’C its an 04 class star and is 1,080 light years away.
Pi the second brightest star, its name Ahadi which means ‘having much promise’ has a magnitude of 2.7 and is a K3 supergiant with a temperature of 3,700’C and is 810 light years away.
Rho magnitude 2.8 F5 supergiant with a temperature of 6,700’C lying at a distance of 65 light years.
Tau magnitude 2.9 ,an orange K1 giant with a temperature of 3,800’C and is 182 light years away.
Xi magnitude 3.4 is a G6 supergiant with a temperature of 4,600’C and is 1,200 light years away.
There are three Messier objects M46,M47 and M93 that require binoculars to see them.
In November 1942 a bright nova appeared in Puppis reaching a magnitude of -0.2

The Thunder Moon

The Thunder Moon

The Full Moon on July 5th is known as the Thunder Moon as this is the month of the year when we are most likely to get thunder storms.

Thursday, 2 July 2020

William Gascoigne 1612-1644

William Gascoigne

In the year 1612 William Gascoigne was born at Thorpe on the Hill, Middleton near Leeds, born just three years after the first use of an astronomical telescope Gascoigne would go on to make major contributions to the construction of accessories to use with telescopes, he would also forge links with some of the most important astronomers of the time, yet have a tragically short life.

He came from a family of local gentry, the Gascoigne coat of arms being the severed head of a golden conger eel. Very little is known of his early years, it is not even certain where he had his formal education. Whereas other people spent their leisure time hawking and hunting William Gascoigne was fascinated by the natural world and the world of instruments and machines.

We do know that by 1638 he was already a very experienced and seasoned astronomer. One point that seems bizarre with regards to his future life is that he received no training in mathematics. During Gascoigne’s lifetime the science of optics and the construction of telescopes were still in its infancy and was still a very secret subject which meant it was difficult for him to obtain books on the subject. However obtain books he did and he then became self-taught in the field of mathematics and optics, in fact what he was doing would be imitated by the world renowned Yorkshire telescope maker Thomas Cooke nearly two hundred years in the future.

By sheer dint of effort and research Gascoigne managed to have constructed a telescope and he even produced the lenses to go with it. The likelihood is that he almost certainly made several telescopes but we just don’t know how many. We know that he definitely had a telescope in 1640 because he was observing the Sun; Gascoigne was using the projection method to observe the Sun safely.

Gascoigne had made friends with two other astronomers William Crabtree 1610-1644 who lived in Manchester, and through Crabtree with Jeremiah Horrocks 1618-1641 who was born near Liverpool but later lived at Much Hoole near Preston, these three astronomers were the first people to start to get a grasp of just how big the solar system was. In 1639 Jeremiah Horrocks predicted that there would be a Transit of Venus, a transit occurs when a planet closer to the Sun than the Earth can be see passing in front of the Sun, this applies to only two planets, Mercury and Venus. While transits of Mercury are quite common those of Venus are extremely rare. Astronomers would use transits of Venus to try to work out how far away the Sun was. The Transit of Venus in 1639 was observed by just two people Horrocks and Crabtree. These three would become a formidable group of North Country astronomers but sadly only for a short period in time. They would all die young and at the time of the English Civil War.

However back to Gascoigne who had one of those lucky breaks in life. A spider had gotten into his telescope and spun a web. We can only assume at first that Gascoigne was pretty annoyed with this pesky spider messing around in his telescope but then he saw that the spider had done him a good turn, the web was very straight and very clear and he instantly realised that this could be used to perform a sight to make sure that you knew exactly where you were looking. He made the first cross hair wire albeit with spider webs.

This spider web technology would in fact be used right up until the Second World War in optical equipment. Gascoigne would quickly appreciate those spiders webs would become an indispensable aid to astronomers. Here was a natural resource that was not only very strong and very straight and being a Yorkshireman quickly realised that they also don’t cost anything.

Gascoigne also suggested that if it was very dark so the web could not be seen a lantern could be placed to allow its light to sufficiently illuminate the web. This illuminating technology would remain the same for the next two centuries.

We have no idea how many telescope sights that Gascoigne would make however in 1640 when William Crabtree visited him he was impressed with the numbers of them produced. Jeremiah Horrocks when hearing of these inventions was full of praise and admiration for Gascoigne.

But Gascoigne did not stop there he now had the means to accurately find an object in the sky, but could he measure how far apart or how was and object in the sky. Taking his spider web technology he mounted two spider webs which were mounted in the field of view and moved towards or away from each other by means of a screw. A scale would show how far apart the webs were. This was the filar micrometer a direct development of the telescope sight. He would become the first astronomer to use a micrometer to measure the angles and positions in the sky. Using his micrometer, Gascoigne made numerous measurements of solar and lunar diameters, plus positions of the stars including the Pleiades or Seven sisters.

Today of course we have equipment that can measure an angle to a precession that Gascoigne could never have imagined. If however we want to trace the time line of today’s measuring equipment right back to the first micrometer, we end up with William Gascoigne at Middleton near Leeds.

The trio would all died in the early 1640s, Jeremiah Horrock in January 1641 from an unknown reason, he never got to try the new micrometer, William Crabtree died in 1644 during the Civil War
but it is unknown if he was killed fighting. We do know that William Gascoigne died at the Battle of Marston Moor on July 2nd fighting on the royalist side for the King.

Much of his work then appeared to be lost or forgotten the micrometer does not seem to appear again until the 1660s about twenty years after the death of Gascoigne. However by chance some of his papers which survived the Civil War and the Great Fire of London came into the possession of Christopher and Richard Townley of Townley Hall in Burnley Lancashire.

They presented the papers to John Flamsteed the first astronomer royal that quickly realised just how important the work done by Horrock, Crabtree and Gascoigne was. Without the work of someone from the red rose county we would not have found out about the wonderful contribution to astronomy of this white rose person.

Astrognome A-Z of Constellations # 67 Piscis Austrinus

Piscis Austrinus The Southern Fish
This constellation has been known since ancient times and is often represented as a fish drinking the flow of water from the urn of the neighbouring Aquarius the water bearer. The fish has been identified with the Babylonian fish god Oannes and is said to be the parent of the zodiacal fish Pisces.
Alpha or Fomalhaut which means the fishes mouth is the most southerly of the 1st magnitude stars from that can be seen from Britain, it is seen autumn can can be found by using the two right hand stars of the square of Pegasus. Fomalhaut is of magnitude 1.2 and is an A3 star with a temperature of 8,000’C and lies at a distance of 25 light years.
Beta magnitude 4.3 is an A1 star 143 light years away with a temperature of 9,300’C..

Wednesday, 1 July 2020

Astrognome A-Z of Constellations # 66 Pisces

Pisces the Fishes
An ancient constellation representing a pair of fishes tied by their tails, the knot being marked by the star alpha. One legend identifies the constellations with Venus and her son Cupid, who turned themselves into fishes and swam away from the attack of the monster Typhon.
The constellations most celebrated feature is that it contains the vernal equinox – the point at which the Sun moves across the celestial equator into the northern hemisphere each year. The point originally lay in Aries, but has now moved into Pisces because of precession, eventually it will move onto in Aquarius. It is still called the First Point of Aries
Alpha or Alrisha which means rope or knot with a magnitude of 3.8 is actually made of two stars of magnitude 4.3 and 5.2, a small telescope will show both stars. Alpha is 311 light years away and is an A class star.
Eta the brightest star in Pisces is known as Al Kargh or outpouring of water with a magnitude of 3.6 , it lies 350 light years away and is a G7 giant star with a temperature of 4,700’ C
Gamma magnitude 3.7 is a G8 class stars with a temperature of 4,600’C and is 138 light years away
FL19 or TX Psc a deep red irregular variable. One of the reddest stars that can be seen by the naked eye. TX varies between magnitude 4.9 – 5.5 in a period of between 224-450 days. Its 900 light years distant.

Tuesday, 30 June 2020

Astrognome A-Z of Constellations # 65 Pictor

Pictor the Painters Easel
A faint constellation overshadowed by the brilliant star Canopus in Carina to one side and the Large Magellanic Cloud in Dorado on the other. The constellation was invented by Lacaille in the 1750s while in the southern hemisphere . It contains the 9th mag star Kapteyn’s star only 12.7 light years away named after the Dutch astronomer who discovered it in 1897. .
Alpha magnitude 3.3 class A8 temperature 7,000 ‘ C, 97 light years way.
Beta magnitude 3.9 A6 class star 8,000 ‘ C ,65 light years away. Beta is a young star only 20-26 million years old but it appears to be surrounded with planetary forming material.