Cooke Telescope Tales - occultation of Saturn observed from South Africa in 1920

 Occultation of a Star by Saturn on March 14^th 1920 made at Rondebosch, South Africa using a 6 inch Thomas Cooke telescope by W Reid, C. L O’B Dutton and W G McIntyre. 

 From the report that was received from South Africa it was assumed that many observers in the north would have seen this occultation but that does not seem the be the case. Due to this exact timings were not prepared. The report says that the star was not following its predicted path although I wonder if what they were really seeing was that Saturn was not quite in its predicted place. 

The time when the star was in contact with the rings was given as 8.46 South African Standard Time however this was a compromise. It was the time when the observers present were all certain that the star was behind the rings. Mr Reid thought it touched the rings 3 minutes earlier and at the time given was on the edge of Ring B 

At first their was very little loss of light, but as soon as it touched Ring B the light gradually faded for about a half a magnitude. It remained this way for a few seconds, when it fell a little further, and almost immediately the flicker took place – that is, the star suddenly almost went out, but not quite, it rose again fairly suddenly. After this its light fluctuated very considerably, but never reached more than a magnitude less than its original brightness. 

The star disappeared behind the planet at 8.54 and re appeared at 10.36. The seeing on the night was very good.

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The Astronomy Show on Drystone Radio

 Join me, Martin Lunn MBE every Monday evening from 7.00 pm-9.00 pm on the award-winning Astronomy Show on Drystone Radio, probably the only regular astronomy show on any radio station in the country. 

I will take my weekly look at the night sky and look at all the latest news in astronomy. There will be the astronomical anniversaries this week plus the latest news from the astronomical societies in the north of England.

The Astronomy Show every Monday evening only on Drystone Radio live online at www.drystoneradio.com DAB radio in Bradford and East Lancashire, or 102 and 103.5 FM and can also be heard later on the Drystone Radio Podcast.

A little ramble through 19th century astronomy - aurora in 1874

Academy, Saturday 28^th February 1874

 Professor Domenico Cipolletti has drawn attention, in the Nazione, to the coincidence of the times of appearance and disappearance of the aurora borealis, seen at Florence on the evening of February 4, and those of the grand auroral display witnessed at the same spot February 4, 1872. The aurora was also seen at Milan and other parts of northern Italy on the 4th, on which evening strong magnetic disturbance was noted at the Vienna and Munich observatories. Professor Cipolletti exhorts observers to watch with special care for any manifestations of sudden light in Jupiter's belts, which have been proved by the observations of Lassell, Proctor, and others, to exhibit the brightest colours at those periods, in which the aurora borealis was most strongly marked.

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Cooke Telescope Tales - telescopes for carlisle in 1857 and 1858

 In February 1857 William Day of Carlisle who was headmaster at the Christchurch Boys School in Carlisle purchased a 4.25 inch portable equatorial telescope. As this was early 1857 it could still be a Thomas Cooke of York telescope rather than a Thomas Cooke & Sons of York, because it was around this time that the company changed its name.

 He also  in early 1858 purchased a smaller 3.5 inch telescope also from Cookes.

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Cooke telescope Tales - telescope for Manchester in 1860s

 Eddowes Bowman 1810-1869 was born in Nantwich in Cheshire and although he considered going into an engineering profession but his career took him into the field of classical literature. 

He became chair of Greek and Latin Classics and Greek and Roman History in Manchester New College. It was also at this time that he developed an interest in natural science. This included astronomy. 

In the early 1860s he purchased a 7.25 Cooke refractor in a specially constructed observatory. I do not know if the observatory was built by Cookes. Due to his many other interests it appears as if the telescope was little used. He died at Victoria Park Manchester. 

Born November 1810 died July 10^th 1869

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Cooke Telescope Tales - T W Backhouse and two comets

On the 27^th September 1892 about 15hrs 30 mins GMT comet Brooks (c1892) had a tail 10 degrees long, pointing at an angle of 280 degrees. 

At the later part of September Swift’s comet (a1892) was still a conspicuous object seen with a 4.5 inch Thomas Cooke refractor. Observations on several nights showed that it not only has  a faint tail- at position angle 260 degrees on the 24^th September at 8hrs and 30 mins, when I observed it to be certainly 11 degrees long, and suspected it to 21 degrees- but that also there was an elongation nearly in the opposite direction.

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A little ramble thbrough the winter sky - Gemini the Twins

 An ancient constellation, Gemini a winter group represents a pair of twins holding hands. They are Castor and Pollux members of the crew of the ship Argo with Jason in search of the golden fleece. The fleece had come from a magic Ram which had been able to fly, after it died its fleece was placed in a sacred grove, guarded by a dragon which Jason killed, and he took the fleece back to his own country.

Castor and Pollux were of mixed parentage although both sons of Leda, Castor’s father was king Tyndareus of Sparta while the father of Pollux was the god Zeus. When Castor died, because he was mortal, Pollux begged his father Zeus to give Castor immortality, and he did, by uniting them together in the heavens.

Alpha or Castor at magnitude 1.9 is the second brightest star in Gemini lying 51 light years from Earth, Castor is an A class star with a temperature of around 10,000’c much hotter the Sun at 5,800’C. Although it appears to the naked eye as a single star there are in fact 6 stars that make up the Castor system

Beta or Pollux with a magnitude of 1.1 is the brightest star, Pollux is 34 light years away and is a K class orange giant star.

There is a minor mystery here because Ptolemy in the 2^nd century stated that Castor was brighter than Pollux whereas now it is the other way around, the Arab astronomers agreed with Ptolemy. So, if the old astronomers were correct we must suppose that either Castor has faded or else Pollux has brightened up. It seems more likely that the change would have occurred in Pollux.

Gamma or Alhena which means the ‘Shining One’ lies 109 light years away and is of magnitude 1.9, it is an A class star.

Eta or Propus which means ‘Forward Foot’ is a M class red giant star, Propus is a variable star and its brightness changes between 3.1-3.9 over a period of around 230 days. The star lies at a distance of about 320 light years.

Epsilon or Mebsuta which means ‘Outstretched Arm’ shines with a brightness of 3.1 and lies at a distance of 840 light years. It is a G class class supergiant star.

Delta or Wasat which means ‘Middle’ is a F class star lying at a distance of 60 light years away, It shines at a magnitude of 3.5. 

Zeta or Mekbuda which means the ‘Outstretched Left Leg, it’s a Cepheid variable varying brightness between magnitude 3.7 and 4.1 every 10.2 days,  Mekbuda is 1,200 light years away and varies between a F7 supergiant to a G class supergiant class star.

Mu or Tejat which means ‘Back Foot’ is 230 light years away and is a M class red giant star that varies very slowly between magnitude 2.7-3.0 in a period of around 70 days.

Messier M 35 is an open cluster around 3,800 light years away containing about 400 stars. M35 can be seen in the sky near eta as a magnitude 5.1 mottled splash of light. Charles Messier saw M35 in 1746.

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