I will be taking a break from Saturday 20th September until Saturday 4th October. I will be visiting the gamma quadrant, I will however be back in the alpha quadrant for my next blog on Monday 6th October.
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Friday, 19 September 2025
A little ramble through 19th century astronomy - The Moon covered in salt an 1873 view
Nature January 23rd 1873
The Moon’s Surface
May not the white, telescopic appearance of the moon’s
surface, resembling snow in many parts, be explained by the fact that the
extinct volcanoes of our satellite are covered with crystals of salt?
Any person who is accustomed to view the moon through a
telescope must, I think, have been struck by the dazzling snow white appearance
of the mountains. May not an explanation of this be deduced from the experience
gained by the last eruption of Vesuvius?
One of the most curious phenomena observed is the power of
burning lava to retain an enormous quantity of water, and salt, which it does
not allow to escape till it begins to cool.
The formation of salt is shown generally over the whole
stretch of lava emitted in 1872. Soon after the surface cools it is covered
with a light crust of salt.
Is it not, therefore, probable that the numerous lava beds
of the extinct volcanoes in our satellite may be coated with salt, bleached to
the whiteness of snow?
C H W Merlin
British Consulate, Athens, November 23rd 1872
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Thursday, 18 September 2025
A little ramble through Delphinus the Dolphin
Delphinus the Dolphin is a small constellation that can be seen in the summer months close to the star Altair one of the summer triangle stars.
There are many stories attached to the constellation, one of the most popular is from Greece where
it is said that a dolphin rescued the musician Arion who was travelling from
Tarentum to Corinth and while playing music charmed some dolphins. When the
crew of the ship he was travelling on robbed him and threw him overboard the
dolphins rescued him and carried Arion on their backs the shore and safety. And
for that good deed a dolphin was placed in the sky forever.
It is one of the smaller of the classical constellations and
as always there are lots of stories concerning it. There is some suggestion
that Hipparchus wanted to place the stars in the constellation Delphinus into
the constellation of Equuleus or Foal. However, this dd not happen and it
stayed as a separate star group, it was always regarded as the most remarkable
of the marine creatures.
The stars alpha, beta, gamma and zeta Delphinus are often
described as representing Job’s Coffin. No one seem to know why or when this
term was first used.
The Roman poet Ovid said it was clarum sidus or the famous
star of the girls and it was personified as Amphitrite the goddess of the sea, because
the dolphin induced Amphitrite to become the wife of Neptune.
The Hindu astronomers knew it as shi-shu-mara or a porpoise
which was also ascribed to Draco.
The Arab astronomer Al Biruni gave it the title Al Ka fidor
the Riding Camel, while other Arabian astronomers referred to it as Dulfirm a
marine animal friendly to man.
Delphinus forms a shape like a small version of the Plough. The two brightest stars are beta and alpha in that order; beta is an F class star and has a magnitude of 3.6 its 97 light years away and has a surface temperature of about 6,500 degrees making it warmer than our Sun. Alpha on the other hand is a B class star with a magnitude of 3.8 and with a surface temperature of around 11,500 degrees and is 241 light years away.
Neither star appears to have a classical name but in 1814 in
the Palermo star catalogue the names
Sualocin were given to alpha while beta became Rotanev. It caused a real
mystery it was a puzzle that Admiral Smythe was unable to solve. This is
strange because he knew the staff at the Palermo Observatory very well. It
would be TW Webb who solved the puzzle, he realised that be reversing the letters and reading Nicolaus Venator, the
Latinised form of Niccolo Cacciatore, this was the name of the assistant and
successor of Piazzi at Palermo.
Epsilon which at magnitude 4.0 has surprisingly got an
Arabic name, it was known as Al Dhanab al Dulfim or the Dolphin’s Tail. Its 330
light years away and is a B class giant star with a very hot temperature of
13,000 degree. While in China the star was known as Pae Chaou or the Rotten
Melon.
Gamma which has no name is a F class star 115 light years
away, with a magnitude of 4.3 and a temperature of around 6,000 degrees similar
to the Sun which has a surface temperature of 5,800 degrees
Delta also has no name is a magnitude 4.3 star an A class
star hotter than the Sun and is 223 light yeas distant.
Wednesday, 17 September 2025
Cooke Telescope Tales - Comet Gale 1912 discovered with a Cooke telescope
Derby Daily Telegraph Tuesday 15th October 1912
Gale’s Comet has been well seen with the 6in. equatorial at Mr. F. J. Hanbury's Observatory, Brockhurst, East Grinstead, during the past week. The Superintendent, however, says in a letter to the Times that it is somewhat north of its predicted place in the ephemeris and the difference is on the increase amounting to nearly one degree last night. It is rising rapidly in declination and appears be brightening, also; when first seen it was estimated about fifth magnitude but now nearer the fourth. It, was really a fine object last night, being found in twilight. On a dark sky it had an extensive coma, with a large bright nucleus and a tail at least half degree length. It was very plain in the finder, and was about south of Alpha Serpentis. sighting along the telescope it was seen with the naked eye, as a little misty spot just below the bright star. It is evidently proving to be a more interesting object than was at first anticipated, and seems likely to remain in view for some little time.
My note
The comet was discovered by Walter Gale at Sydney NSW on
September 8th 1912. He may have made the discovery with his 6.5 inch
Thomas Cooke telescope
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Tuesday, 16 September 2025
A little ramble through 19th century astronomy - Theft of OG from Alleghany Observatory in 1872
On the night of July 7th/8th 1872, the object glass of the Alleghany Observatory was stolen, as also a few eyepieces belong to the Transit Instrument.
It is thought that the object of the thief is to try to extort
a large reward for its return, but Mr Langley, the director of the Observatory,
has resolved not to offer a reward, nor guarantee immunity from punishment to
the culprit. This he deems a duty to others who may have the charge of similar
instruments.
www.theramblingastronomer.co.uk
Monday, 15 September 2025
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 - The 9.5 inch Cooke telescope at Chevreuse Observatory in 1908
Maurice Farman and the Chevreuse Observatory
As far as I am aware this is the not the same Maurice Farman who was an early pioneer in the days of flight, but I am always ready to be proved wrong.
In 1908 while observing at the Chevreuse Obseravtory near Paris, an observatory I have never heard of before observed 1,100 double stars while using a 9.5 inch Cooke telescope.
His observations were apparently quite brief and usually
consisted of just one line of information, many additional notes were drawn from historical observations of
the stars he observed in 1908.
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