A little ramble through Libra the Scales

 A small faint constellation of the zodiac, the ancient Greeks knew it as the ‘claws of the scorpion’ an extension of the neighbouring constellation of the Scorpion, rather than the scales we see it as today.

However, the Romans made it a separate constellation at the time of Julius Caesar. Since then the scales of Libra have come to be regarded the symbol of justice held aloft by the goddess of justice Astraea.

The Arab astronomers knew these stars as Al Zubana or the Claws. Syrain astronomers regarded it as Masa’tha the scales the Persians also saw  a set of scales but called it Terazu.

In India it was Tula the balance while in China it was known to early astronomers as Show Sing the Star of Longevity bit later it became Tien Ching the Celestial Balance.

Alpha or Zubenelgenubi which means the ‘Southern Claw’ is actually the second brightest star with a magnitude of mag 2.7 lying at a distance of 77 light years. Zubenelgenubi is a F3 class star. A pair of binoculars will reveal that alpha is actually a double star.

Beta or Zubeneschamali or ‘Northern Claw, is actually the brightest star at magnitude  2,6 lying at a distance of 185 light years. Zubeneschmali is a B8 class star.

Gamma or Zubenelakrab or ‘Scorpion’s Claw’ magnitude 3.9 and a G8 giant star lying at a distance of 163 light years. 

Ther are no clusters or galaxies brighter than magnitude 9 in Libra

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Cooke Telescope Tales -Transit of Mercury May 7th 1878 & 1924

Mercury is the closest planet to the Sun in our solar system and there will be times that it will pass in front of the Sun and can be seen as a small dot slowly moving across the face of the Sun. This is a Transit of Mercury, they occur on average 13 times per century, the last was in November 2019 the next will be in 2032. 

Here is a little-known astronomical fact, two transits of Mercury separated by 46 years which occurred on the same date and were both seen using Cooke of York telescopes. 

The transit of Mercury on May 7^th 1878 (it was May 6^th in the UK) was observed at 06 hours and 40 minutes as the Sun rose in Australia, with Mercury already halfway across the surface of the Sun, this observation was made by W J MacDonnell at Sydney using a 4.25 inch Cooke telescope. 

Then 46 years later in 1924 also on May 7^th A F Bennett this time using a 6 inch Cooke telescope started observing a Transit of Mercury from 16 hours and 57 minutes from his home in Suffolk. 

Although he lived in Suffolk, he was actually born in Goole East Yorkshire and was educated at Bramham College.

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Cooke Telescope tales - York Exhibition 1881

 Yorkshire Gazette Saturday 7^th May 1881 

York Exhibition 

In the space intervening between the central and Great Halls, a large equatorial mounted telescope which stands 15 feet high is exhibited by Messrs T Cooke & Sons York opticians, the instrument which is an object of curiosity with an object glass of 10 inches.

 

The sale price is £1200 (my note; today that telescope would cost over £186,000)

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A little ramble through 19th century astronomy - Messier 11

 Nature August 5^th 1875

The Great Cluster messier 11

As the first special publication of the Observatory of Hamburg, we have Prof. Helmert’s memoir detailing the results of his micrometrical observations of the components of this well-known cluster in the constellation of Aquila or in Clypeum or Scutum Sobieski, as many of the continental astronomers continue to call that part of the heavens which it is situate.

The memoir has a particular interest from the circumstance of Dr Lamont having similarly employed the Munich refractor in the years 1836-39.The investigation of any changes that may take place in the constituents of these groups of stars, as regards position or brightness, becomes a very attractive one, and as we know from the excellent work of Heer Pihl on the Perseus Cluster, it is not one always requiring the use of large instruments, such as have been employed in the hands of Lamont and Helmert, upon Messiewr 11.

D’Arrest terms this cluster ”magnifica innumerabilium stellarum coaservatio”; the amateur will remember Admiral Smyth’s comparison of the configuration of the components  to “ a flight of wild ducks”

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Cooke Telescope Tales - telescope for Brussels in 1880

 Yorkshire Gazette Saturday 15^th May 1880 

A York Telescope for Brussels Observatory 

Messrs T Cooke & Sons, opticians of this city, had the honour some time ago of receiving an order from the Belgium Government for an equatorial mounting for a telescope with an object glass of 15 inches diameter, which is to be placed in the Royal Observatory Brussels. 

The work has just been completed, and the instrument presents a fine specimen of mechanical art and skill. The tube about 21 feet in length, and the stand 13 feet high. The instrument is fitted with all the latest appliances, including clockwork of very delicate construction by which the telescope caused to follow the movement of the star on which it is fixed. The firm expect to pack and forward the instrument towards the end of the month. 

 

York Herald Saturday 15^th May 1880 

The telescope for the Belgium Government may be inspected by those whose who are interested

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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 - A third comet of 1813?

 Nature July 29^th 1875

A third Comet in 1813?

Bode after mentioning in his miscellaneous Notices (Berl. Jahrb 1818) that canon Stark of Augsburg had observed the first comet of 1813 on the 19^th February, states that Stark had also discovered on the same evening with a 3.5 feet Dollond telescope, a very small and exceedingly faint comet without tail above the variable star Mira in Cetus. Cloudy skies are said to have prevented further observation.

Bode remarks with respect to this comet that it is strange that no other astronomer had perceived it. However suspicion this circumstance may have appeared , we know that several of the comets of short period have been revolving in such orbits for one or two centuries, visiting these parts of space without doubt under favourable circumstances for observation on more than one occasion, yet entirely esc aping detection , so that the mere fact of a single observer only having seen a comet, is hardly a sufficient argument against its existence.

The late Prof D’Arrest even thought it worthwhile to submit the reputed observations of the D’Angois-comet of 1784 to further circulation, notwithstanding Encke’s well know investigation in the “Correspondance Astronomique” of the Baron de Zach and we may have something to say on this subject in a future column.

Not having seen any reference to “Starks Comet” in English astronomical works, we have given the particulars recorded of it here.

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