The Astronomy Show

 

Join me, Martin Lunn tonight and every Monday evening from 7.00 pm-9.00 pm on the Astronomy Show, 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 A-Z of Constellations and the Messier Marathon.

The Astronomy Show every Monday evening only on Drystone Radio 102 and 103.5 FM the show can be heard live on line at www.drystoneradio.com and the show can be heard later on the Drystone Radio Podcast.

A Cooke mounting for India

 

In 1868 F Doderet in Madras in India purchased a simple equatorial mounting for a 5 foot telescope. I don’t know if the telescope was a Cooke or not. The mounting came equipped with leather straps to hold the telescope, on a short tripod.

Another small Cooke

 

W T Dewesbury of Skelton I assume near York purchased in 1857 a 3.5 inch telescope with a plain mounting. There was a finder, steadying rods, four eyepieces, sun mirror, pancratic eyepiece. All of the above was in a box. The cost was £30, In 2022 that would equate to £3,600.

A Cooke Camera took Shackleton's Endurance Photographs

 

The Endurance 22 Expedition will be using the latest technology looking for the wreck of the ship Endurance which was crushed by ice in 1915. This was the ship used by Ernest Shackleton and his crew on their mission to try to walk across Antarctica. Just as the Endurance 22 team are using the latest technology Shackleton used the latest technology to document his mission.

The official photographer was the Australian, Frank Hurley, and he chose a Graflex camera and as he wanted the best lenses available he used those made by Thomas Cooke & Sons of York to document the expedition.

As the Endurance 22 mission evolves over the next few weeks I am sure there will be lots of press coverage and when those images taken taken by Frank Hurley are shown, don’t forget he was using a Cooke lens.

It is worth noting that in 1912 Captain Scott had taken a Thomas Cooke & Sons theodolite with his to be able to accurately plot the point that he reached the south pole.

Another Cooke for London

 

Sir Thomas Cunningham of Eaton Place Belgrave Square London purchased in 1858 from Thomas Cooke & Sons a universal 3.5 equatorial telescope.

Jupiter observed from India with a Cooke

 

The Rev J Spear observed Jupiter, Saturn and Mars in 1870 from Chukrata N W Provence's, Bengal, India using a Thomas Cooke & Sons 4.5 inch telescope.

Flamsteed Catalogue Anomalies

 

I use my Fuji XT2 camera to take short 5 second exposures of star fields well away from the galactic plane. I am looking for high latitude novae. I just can’t be bothered to go below magnitude 9.0, there are too many stars to check.

John Flamsteed 1646-1719 produced a catalogue of naked eye stars in the various constellations that were visible to him. I keep coming across anomalies with stars that have Flamsteed numbers (Fl). I sometimes come across stars that are much brighter than the stars around them yet they don’t have a Fl number, they are clearly visible to the naked eye, but were not recorded by Flamsteed. On the other hand there are some Fl stars that are below naked eye visibility yet still have a Fl number!

Either the stars have changed over the past 300 years or were misidentified by him, or his charts were changed by someone after his death. I run all the usual checks through various catalogues to see if there is any data on them. There usually isn’t. This is one example:-

In-between Fl 32 Uma and Fl 35 UMa is an unmarked star which is brighter than both of these stars.

 The star is actually now known as ET Uma, it is an alpha2 Canum Venaticorum type variable. These are magnetic variables whose amplitude is very tiny, usually no more than 0.1 of a magnitude. This is a white A class star. It is listed with a magnitude of 4.9.

This is much brighter than FL32 at magnitude 5.7, also an A class star and Fl 35 at magnitude 6.3 which is of course below naked eye visibility and in theory would not have been seen by Flamsteed yet has a FL number. Fl 35 is an orange K class star.

Does anyone else come across these discrepancies when they check their photographs.