A little ramble through Mensa the Table Mountain

 A constellation introduced by the French astronomer  Nicolas Lacaille in the 1750s.  It is a southern hemisphere group and celebrates the Table Mountain at the Cape of Good Hope in South Africa from where he observed the night sky.

It’s one claim to fame is that part of the Large Magellanic Cloud strays from the neighbouring constellation of Dorado the Goldfish, over the border into Mensa possibly reminding Lacaille of the cloud that frequently covers the real Table Mountain.

Unfortunately, the constellation is very faint and unimportant.

The brightest star is alpha which at only magnitude 5.1 can be masked by any mist or moonlight. Alpha is a G class star, 33 light years away.

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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 - The second comet of 1702

 Nature February 3^rd 1876

A complete reduction and discussion of the observation of this comet, taken at Rome by Bianchini and Maraldi, does not afford indications of elliptical motion, as might be surmised to exist from the small inclination of the orbit to the ecliptic and the direct movement. In fact these observations appear to be by no means precise, and the differences from calculation inter se are too irregular to afford any hope of sensibly improving upon the orbit given by Burckhardt.

Considering the differences of right ascension between the comet and com parison stars were taken by means of clocks, and the differences of declination measured by a micrometer scale, the arc value of which was determined by observation of the Sun’s diameter, rather better places might have been looked for.

The comet was its least distance from the earth on the night of April 19^th.

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Cooke Telescope Tales - Dark transit of Titan in 1907

On November 5^th / 6^th 1907 Mr A B Cobham and Mr G D Hirst using a 4.5 inch Thomas Cooke & Son telescope in Australia saw a dark spot on Saturn. This was afterwards ascertained to be Titan. 

They also both commented that they caught glimpse of the edge of the ring at flashes, the impression indicating the extreme fineness and delicacy of the rings when seen edgewise.

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Cooke Telescope tales - Jupiter observed from Australia in 1877

 York Herald Thursday 22^nd March 1877 

Important Astronomical Observations by means of a York telescope 

Strange news has been recently received from an Australian observatory (Adelaide). It might be described as revolutionising our ideas respecting the largest of the planets, were it not that the careful study of much older observations had already led the more advanced students of astronomy to adopt the theory which has now been demonstrated by direct observation.  

During the last eight or none years the belief has been gaining ground that the giant planets Jupiter and Saturn are in a state of intense heat and enwrapped in atmospheres of enormous depth and density. In fact it may be said that according to the new theory we never see the actual body of either Jupiter or Saturn, but only the outermost surfaces of the cloud layers; the real surfaces lying, not a few miles, or a few hundred miles but several thousand miles below the cloud surface measured by astronomers. 

It has been shown that all the phenomena presented by the two gas giants planets correspond with this theory, whereas not one in ten can be explained by the older theory. 

Fortunately in the case of Jupiter, we have evidence we have evidence from the Adelaide Observatory where a fine (8 inch) telescope by T Cooke & Sons of York has been erected, and where a singular purity of air greatly assists astronomical observation, two practised observers (Mr Todd and Mr Ringwood) on two different occasions, both observing  on each occasion saw the nearest of Jupiter’s satellites through the outer layer of the planet’s cloud laden atmosphere, which must, therefore, of necessity, be at least 2,000 miles in depth. 

In his book ‘Flowers in the Sky’ Richard Proctor makes references to this observation by Mr Todd and Mr Ringwood.

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A little ramble through 19th century astronomy - occultation of Pleiadum in 1876

 Nature, January  20^th  1876

Atlas 27 Pleiadum

A very interesting observation was made at Strasburg on the occasion of the occultation of this star – a Struve’s difficillima – on the 7^th of the present month. As we recently stated, this star does not appear to have been seen double since the last Dorpat observation in 1830. On the 7^th inst., however Herr Hartwig observing at Strasburg with an excellent Fraunhofer of 42 lines aperture power 159, remarked that the star did not disappear instantaneously ; after the principal mass of light had vanished there remained a luminous point for about six tenths of a second, a circumstance which favours the duplicity of the object notwithstanding the failure of recent efforts to divide it.

It brings to our attention Burg’s observation of the occultation of Antares 1819 April 13, when at emersion the star appeared to suddenly increase from one of the sixth or seventh magnitude to one of the first, a phenomenon no doubt attributable to the existence of the small companion on the parallel, preceding the principal star (*Natrure, vol xii,p308).

The next occultation of the Atlas – Pleiadum on February 3 , will not be visible in this country, but may be well observed in the United States. The American ephemeris gives the time of immersion for Washington; at the observatory of Hamilton College, Clinton, NY so actively conducted by Prof. Peters, the immersion takes place at 11h 13m, and emersion at 12h 4m.

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Cooke Telescope tales - partial eclipse of sun in 1900

 A Partial solar eclipse of Sun May 28^th 1900  was observed using the G J Newbegin  9 inch Cooke telescope with a power of 75  by Mrs Newbegin and Rev T E R Phillips using the projection method. The image produced was 4.2 inches in diameter.

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