Nature March 16th 1876
Miss Sheepshanks has presented to the Royal Astronomical
Society 200 volumes of works on astronomy, some of them very rare; Lord Lindsay
has presented a large and valuable collection of the late Mr Carrington’s MSS
on the subject of sun spots.
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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.
In 1903 Thomas Cooke & Sons of York supplied a 4.5 inch telescope to the Government Observatory in Calcutta, India. The head of the observatory was Mr Evershed, Attached to the telescope was a 5 inch Camera also supplied by Cookes.
The
telescope was mounted on a Cooke iron pillar which were housed in a shed. This
shed was mounted on wheels and rails that allowed it to be moved when the
telescope was to be used.
The University of Toronto’s David Dunlap observatory at Richmond Hill near Toronto, Canada today houses a 74 inch Grubb Parsons reflector that was installed in 1935. However there was a much older observatory in Toronto.
This was the Toronto Magnetic and Meteorological Observatory
at the University of Toronto which
housed a 6 inch Thomas Cooke & Sons telescope that was installed in
1880. The Cooke was used in particular for the study of sun spots in
conjunction with magnetic measurements made at the observatory. I believe that
the Cooke may have been used until around 1910.
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The “dog days of summer” is a phrase used to describe the hot and humid days of summer. It can be traced back thousands of years. It refers to the dates from July 3 through August 11, which is 20 days prior and 20 days after the star Sirius rises and falls in conjunction [sharing the same spot in our sky] with the sun. Sirius was known as the “Dog Star,” because it is the brightest star in the constellation Canis Major (Large Dog).
Sirius is the brightest star in the sky. The name Sirius
comes from an ancient Greek word for “scorching” or “glowing.”
Since Sirius is in conjunction with the sun on July 23, the
dog days of summer center around then. The dog days of summer fall between July
3 to August 11, and that’s when we have many of our warmest days in the
Northern Hemisphere.
Now we often have very hot days before or after July 3 to
August 11 however the legend of the dog days has survived.
Nature March 16th 1876
Comet 1840
In Astronomische Nachrichten, No. 2079, Dr Kowalczyk, of
Warsaw, publishes I his investigation of a definitive orbit for the comet
discovered at Berlin by prof Galle, the present Director pf the observatory at
Breslau, on the 25th January 1840.
This comet which was last observed at Kremsmunster on the 1st
April, had already been made the subject of extensive calculation b y
Professors Plantamour and Loomis. The former in 1843, discussing his own series
of careful observations taken at Geneva, found (Astron Nach, No. 476) that a
parabolic orbit represented the comet’s course within the probable limits of
error of observation; on including the series taken at Berlin he found the most
probable orbit to be an ellipse, but of great eccentricity to which little weight was considered to attach.
Loomis on his side, taking into account the effect of
planetary perturbation during the
interval of the comet’ visibility, also found an ellipse, but with a mote
moderate eccentricity, the period of revolution being about 2,400 years; the
sum of the squares of the errors of the
ellipse is diminished to one third the amount with the best determinable
parabola.
Loomis’s investigation will be found in the Transactions of
the American Academy vol viii; his orbits are not in the included in the
extensive collection in Dr Carl’s “Repertorium der Cometen-Astronomie”, a work
which notwithstanding, its great utility
to the student of this branch of science, is yet not complete or free
from numerical errors.
Kowalczyk starts with the parabolic elements obtained by Plantamour in 1843, comparing them with the whole course of observations. After introducing the corrections for aberrations and parallax , and the earth’s position from Leverrier’s tables, instead of those from the tables of Carlini used by previous computers and by the usual method of equations of conditions for ten normal places, he finally arrives at an elliptical orbit, very closely agreeing with observations, and showing a period of revolution of 3,789
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years.
On July 6, Earth will be at aphelion, the furthest point from the Sun it can reach on its yearly orbit. At aphelion, Earth will be 94,502,963 million miles (152, 087,778 million km) from the Sun. Earth was at perihelion, its closest point to the Sun, during January, when it was only 91,403 ,640 million miles (147,099,900 million km) away.
The seasons are caused not by how close Earth is to the Sun, but by which hemisphere is tilted towards it. In July the northern hemisphere is tilted towards the Sun, so we have summer, while in January, when Earth is closest to the Sun, the northern hemisphere is tilted away from it and we have winter.
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