Cooke Telescope tales - Mosquito net helps Australian astronomers

 James Nangle at Marrickville in New South Wales using a 6.25 inch telescope which I have recently discovered was a Thomas Cooke rather than a Thomas Cooke and Sons telescope which means it was made before 1857, observed Mars in 1909. 

He described the darkish areas to have a greenish tinge, with the Mars Cimmerium and Syrtis Major looking like the tops of trees in an Australian valley when seen from the top of a mountain. The northern snows were also well seen. There appeared none of the canals that had been drawn by Schiaparelli or Lowell.

 On almost all occasions when a great increase in definition was required a screen of mosquito net was placed immediately in front of the object glass. Such a screen is evidently a good idea, since it slightly reduces the glare without interfering with the separating power, that vital point in all detailed planetary observations.

                                                         www.theramblingastronoer.co.uk

A little ramble through the night sky - The June micro Strawberry Moon

Most people will have heard of the supermoon but far fewer people will know of the micromoon. 

The Moon takes around one month to orbit the Earth. Its normal distance from us is 239,000 miles.  A micro moon occurs when the Moon is more than 250,000 miles away. A supermoon is when the Moon is less than 230,000 miles away.  This is why a supermoon appears larger than normal, while a micromoon appears smaller. The discrepancy happens because the Moon does not orbit the Earth in a circle but in an ellipse or egg shape.

On June 29th we will have the last of the Micromoons for 2026. This will be the the micro Strawberry Moon.

                                                   www.theramblingastronomer.co.uk

A little ramble through 19th century astronomy - R Lepus in 1876

 Nature February 17^th 1876

The Variable Star R Leporis

This highly coloured star, the variability of which was detected by Schmidt in 1855, is calculated to be at maximum on the 28^th of the present month. The mean period appears to be about 438 days, 230 days being occupied in passing from minimum to maximum, and 208 days from maximum to minimum.

Probably the irregularities of variation which have been suspected are to be mainly attributed to the difficulty attending comparison of a star of such intensely red colour. With regard to the colour, however there is something more thana suspicion that it has sensibly diminished in intensity sine attention was first directed to it (Hind 1845 October)

We are almost wholly indebted to Schmidt, who makes such excellent use of the favourable astronomical conditions under which he is placed at Athens, for our knowledge of the law of variation in R Leporis.

                                                    www.theramblingastronomer.co.uk

Cooke Telescope Tales - alpha Centauri observeed in 1906

Alpha Centauri one of the leading double stars in the southern hemisphere was observed by G D Hirst using his 4.25 inch Cooke telescope and James Nangle using his 6.25 inch Cooke telescope in Australia in June and July 1906.

                                                       www.theramblingastronomer.co.uk

 

 

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.

                                                     www.theramblingastronomer.co.uk

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.

                                                    www.theramblingastronomer.co.uk