A little ramble through the night sky - the Micro Blue Moon on May 31st.

It’s May Moon Madness this month, as there are two full moons,  meaning the second one is a Blue Moon, and in addition, both are Micro Moons. The last time this happened was in October 2020 and the next will be in July 2053.

There will be two full moons this month, one on the first and the other on the thirty-first. This second one is referred to nowadays as a ‘Blue Moon’. The Moon takes around twenty-nine and a half days to orbit the Earth once and apart from February all months have either thirty or thirty-one days, meaning it is possible to have two full moons in a calendar month.

This use of the term ‘blue moon’ only has a history dating back to the 1940s when a letter, sent to the American astronomy magazine ‘Sky and Telescope’ (which incidentally is still published) asked the question ‘what is a blue moon?’. The answer was that it is the second full moon in a calendar month. The publishers of the magazine, realising that they had given the wrong answer, retracted their original statement. However, it was too late; the genie was out of the bottle, and for the last eighty years everyone has accepted this definition.

I have my own theory about the term ‘blue moon’. Each month I give the name of the next full moon, and as I often say, these names go back to the times of the monastic period in Britain around 1,000 years ago. The monks, who were amongst the cleverest people around during the Middle Ages due to their vast monastic libraries, knew full well that in some years there were thirteen full moons, rather the normal twelve.

Monks liked order in their lives. They kept diaries and special dates were always marked in red ink. The phrase ‘a red letter day’ is a monastic saying going back over 1,000 years. I just wonder if, when this 13th full moon occurred, it was marked in diaries in blue ink as a source of irritation because it messed up a very orderly system. I once checked the reference library in York minster without success, but maybe someone in the future will check the Vatican library and discover a monk’s diary with a full moon marked in blue ink!

You have probably heard of the Super Moon, but did you know we also have the Micro Moon?

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.

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A little ramble through 19th century astronomy - a notable shoemaker died in 1896

 Sheffield Daily Telegraph Tuesday 4^th February 1896

 

On Sunday morning- there was carried to the grave at Darlington Cemetery Mr. W. H. Harris, who was a working shoemaker, living in a poor neighbourhood, at Hank Top, Darlington. Mr. Harris, who was 54 years old the time his death, was born at Barnard Castle.

 

Though working hard at his trade, he had attained local celebrity as an astronomer, and maker of telescopes with 9 inch and 12inch mirrors, which he, ground, figured, and silvered. This work required nice mathematical calculations, which he carefully worked out. He had intimate knowledge of optics, botany, astronomy, electricity, etc., and was a good French scholar. Mr. Harris was self-taught.

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A little ramble through 19th century astronomy - comet observed in 1819

 Leeds Intelligencer Monday 12^th July 1819

The following communication from Mr. Christie of the Royal Military Academy, Woolwich, contains probably all that can be yet known of this celestial phenomenon:— “I first observed the comet," observes Mr. Christie, “last night (Saturday) a minutes before 11 o'clock, and judge that it came to the meridian about 12. Its elevation above the horizon appeared about 10°, and the sun being at the time nearly below, its distance from the sun cannot much exceed 25°.

 

The night was remarkably light, and the moon uncovered by clouds—circumstances extremely unfavourable to the brilliancy of its appearance; and considering this, I should judge that, under more favourable circumstances, its splendour would be equal to that of any comet upon record—the head viewed with Capella (to the east of it) in brilliancy. The length of the tail, which, when the comet was on the meridian, pointed somewhat to the west of the zenith, extended about 15degrees;  and unlike the comet of 1811, it appeared to proceed immediately from the nucleus.

 

 I viewed it for some time through an excellent small reflector, by Watson, and observed, that the nucleus was much denser than that of the former comet, and that there was no separation between it and the coma, but that the body became gradually rarer, and in the upper part expanded into the tail; which appearance may arise from a very dense atmosphere surrounding the nucleus, and reaching to the rarer fluid forming the tail, if there be any distinction between the two fluids, as appears to have been the case with the comet 1811. 

I may observe, that this as in all other comets, the appearance to the naked eye is much more striking and brilliant than through telescope. The Comet passed the meridian below the Pole, at the Royal Observatory, Greenwich, on Saturday, July 3, about midnight, when its place was determined as follows 

 Apparent right ascension  6h. 51m. 56S

North polar distance, corrected for re fraction 43 d 18 m  47.s

 Mean time of observation .12h 6m 56s

 

 The Comet was again observed on Monday night (July 5), but not till it had passed the meridian, when the following observations was made :

Apparent right ascension . 7h. 0m 9s

 North Polar Distance 43 d 34m 48s

Mean time of observation  12h 36m 04s

 

This was comet 1819 also known as Trailes comet that was discovered on July 1^st 1819 by the German astronomer Johann Georg Trailes. The comet was an easy naked eye object reaching between magnitude 1 to 2.

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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.

 

Cooke Telescope Tales - solar eclipse in Ceylon 1871

 Englishman's Overland Mail Wednesday 27^th December 1871 

 

The Eclipse as Observed in Ceylon 

The solar eclipse on December 12^th 1871 was most favourably observed at all the stations occupied by the scientific party under Mr Lockyer’s direction as well as by Mr Janssen. Important scientific results may be expected  to be shortly made known as indicated in the the message from Mr Lockyer. 

Here in Colombo the weather during the eventful morning was all that could be desired, but being beyond the line of totality and shadow no special scientific value can be attached to the highly interesting observations made here by several gentlemen. 

Our column this time will be unusually full of information respecting the eclipse and the special expeditions sent from home to observe it. About 3.5 inches of rain fell in Colombo between 8 00 pm on the 11^th and 5.00 am on the 12^th. We add the results of local observations:- the Sun rose obscured by clouds, which cleared off by about 6.30 .The whole surface of the Sun presented the usual strippled broken appearance, with here and there large spots. In the neighbourhood of these spots the strippling was more apparent than over the parts free of spots, but they came out in bold relief on the part of the Sun  close to the Moon’s limb. Probably this increase of distinctness was caused by contrast of the black spot &c of the dark limb of the moon. This could not be seen through the 3-inch telescope. Some little time before the greatest obscuration a halo was visible around the sun, which gave place to short bright rays. This latter appearance was probably an ocular deception, as no trace of it was visible through the 4.5-inch telescope under a low power. 

At the greatest obscuration no trace of corona was observable through the same instrument, with a solar eyepiece with a power of about 30. This was carefully looked for. The unobscured portion of the sun, about 15-16ths of its disc, was well defined, without appendages of any kind. Towards the time of centrality the diminution of daylight was very conspicuous—going from the open air into the house it was very striking. Standing in the centre of the room, and looking through the open window, the sun-shine outside was of a neutral tint. The crows commenced to assemble on the tree-tops, cawing after their usual fashion, when preparing for their night's rest. The planet Venus, high in the sky, was distinctly visible to the naked eye, and Jupiter, low down in the western horizon, was plainly discernible with the aid of an opera-glass. The thermometer at the commencement of the eclipse indicated 91.5 °F  in the sun.  At 7-15 it showed a rise of 2.5 degrees and at the greatest phase it had  fallen to 84.5°.  In the shade it stood at 76 degrees; at 6-45 and at the greatest obscuration at 75°  At 9-10, with the full blaze of the then unobscured sun, the thermometer indicated 113 °; in the shade 81°. 

 Mr. Van Dort, of the Surveyor- General's Department, with the aid of a 3-inch telescope, power 50, made some careful drawings of the different phases of the eclipse. The attempt to take the time of first contact and the ending of the eclipse proved abortive. An ordinary watch was the only time- keeper at hand. 

Instruments used in the above observations : Equatorial Telescope by Cooke and Sons, of York, 4.5  inches clear aperture, 66 inches focal length. Telescope by same makers, 3 inches clear aperture, 42 inches focal length, mounted on tripod stand." 

The above indicates the result of observations taken by Mr. Stainfurth Green at his residence in Colpetty. Mr. Stoddart, of the Surveyor- General's Office, took observations at the local observatory, showing the actual time to be 

First contact 06 h 47m 30 s am 

Greatest darkness 07h.50 m15s

Last contact 09h.00 m 20s 

Mr. W. L.H Skeen took some very successful photographic views, which show not only the progress of the eclipse, but the direction and form of the huge rays, projected from the sun or its corona, so much talked of.—Ceylon Observer.

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A little ramble through 19th century astronomy - Fl 4 Aquarius

 Nature August 12^th 1875

The Binary star 4 Aquarius

If good measures if this stars are practicable during the present season, an idea of the form of the orbit may perhaps be obtained. Dawes’s series of epochs will be material service in this respect; without them, doubt might have been occasioned by the two discordant epochs of Madler, which may have been owing to distorted images at low altitude.

The object is certainly one of considerable difficulty, and really trustworthy measures are perhaps only to be expected from practised observers in command of instruments of excellent definition. In Barclay’s second catalogue it is described as just elongated in the direction 144 degrees, with power of 450 on the 10 inch refractor at Leyton at th epoch 1865.74; this angle shows direct progress, very much in accordance with Dawes’s measures. Possibly the companion may now be found nearly due south of the primary.

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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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