A little ramble through 19th century astronomy - rho Eridanus in the 1850s

Nature October 28^th 1875

Rho Eridanus

In the year 1850 the Late Captain Jacob calculated two orbits for this binary system, the second of which represents very fairly his subsequent measures to the end of 1857, a rather severe test for elements founded upon the data available in 1850.

We look in vain for measures later than Capt. Jacob’s though it may be hoped this and other interesting objects of the southern heavens have not been entirely neglected of late years. The public observatories are perhaps too closely occupied with other work to allow much being expected from them in a class of observation peculiarly  suited to the amateur astronomer, but there must be a grand field of operations for private observers, in southern double and variable star astronomy.

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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 - partial eclipse of the Moon in 1892

 The Partial Lunar Eclipse of May 11-12, 1892. By G. J. NEWBEGIN, F.R.A.S. 

The night of May 11-12 turned out so exceptionally clear and fine that (though in 16 ° of Declination) the moon soon became a steady object in the telescope. With regard to the eclipse I decided to take a series of photographs at about half-hour intervals, and to endeavour to secure a permanent record of its several stages. The exposures were made at 9.20, 9.50, 10.30, 11, 11.30 p.m., 12 o'clock midnight, and 12.30 a.m. The periods of exposure were varied, to allow for the decreasing illumination of the moon, viz. :— 20s 20s 30s 40s 30s 20s 20s respectively. 

The plates were the Ilford ordinary, developed by hydroquinone. The instrument by which they were taken is a 9-inch Cooke equatorial, aperture reduced to 2-inch for the whole series. The intervals between the exposures were occupied in developing the plates. 

Thorpe, Norwich, Nov. 11, 1892.

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A little ramble through Lynx

 A decidedly obscure constellation despite its size, it is the 28th largest of the 88 constellations. It was introduced by Polish astronomer Johannes Hevelius in 1687 to fill the gap between Ursa Major and Auriga. He named it Lynx because only the lynx eyed would be able to examine it.

Many of the stars that are in Lynx would have during the times of the Greek astronomer Arato (315-240 BCE) have been placed in Ursa Major the Great Bear.

Alpha magnitude 3.1 is an orange K class giant star lying at a distance of 203 light years, alpha has a magnitude of 3.1.

NGC 2419

Possibly the most distant globular cluster in our galaxy lying at a distance of 300,000 light years, it can be seen as a magnitude 9.1. It was discovered by William Herschel in 1788 and is often called the intergalactic wanderer because at first astronomers thought it was not part of our Milky Way galaxy, we know now that it is.

NGC 2419 would be the "best and brightest" for any observers in the Andromeda Galaxy, looking for globular clusters in our galaxy since it lies outside the obscuring density of the main disk.

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A little ramble in the night sky- Jupiter and Venus coming together June 9th and 10th

 On June 9th and June 10th there will be a spectacular meeting of planets as Jupiter and Venus will be very close together in the sky. You do not need binoculars or a telescope to see this fantastic sight, you can watch this with the naked eye.

If you look to the west, this is the area of sky where the Sun sets at around 9.30pm and then if you wait until just after 10.00pm you will see a very bright white dot low in the west this is Venus and just below it will be a slightly less bright white dot which is Jupiter.

The following night June 10th at about the same time in the evening  you will  notice that although both planets are still close together they will have slightly changed position relevant to each other. As the month of June goes on Jupiter will get lower in the sky.

If you are very lucky you might just catch a glimpse of Mercury which will be lower in the sky and fainter than Jupiter and Venus.

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Cooke Telescope Tales - New Observatory in Catania in 1890

 This observatory which was completed in 1890 is principally for astrophysics, celestial photography, meteorology and seismology. There is a 6-inch Cooke fitted with photographic apparatus; Huggins's apparatus for photographing the solar corona; Mascart's apparatus for photographing atmospherical electricity, &c.

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A little ramble through 19th century astronomy - The Nebulae in the Pleiades

 Nature October 7^th 1875

In No.5 of “Publicazioni del Reale Osservatorio di Brera in Milano”, Herr Tempel has laid down the stars from the Pleiades, from the Durchmusterung , and traced the outline of the nebula near Merope as it appeared to him with a magnifying power of twenty four on a telescope of four inches aperture. The outline is shown to be elliptical, one extremity of the longer axis, the northern one, at Merope, and the inclination of this axis to the circle of declination about 18 degrees, so that as referred to Merope, the angle of position of the longer axis is 198 degrees.

M Wolf, of the Observatory of Paris, observing with the telescope of 0.31m aperture  in March 1874, perceived two nuclei, one almost concentric with Merope, the other and brighter of the two at a distance of about seven seconds, on the same parallel, following.  From the month of November 1874 to the end of February 1875 the nebula could not be seen notwithstanding the very favourable atmospheric conditions, and at the same time M Stephan was unable to detect it with the telescope of 0.80m. M Wolf concludes that the nebula is certainly variable and that its period is pretty short.

Herr Tempel remarks that generally the nebula has been much more readily seen with small telescopes than with large ones, and doubt has been expressed as to any real variability of light; yet it is not easy to understand, except upon this supposition, why the nebula should be visible at certain times in a particular telescope and invisible at others, the circumstances of the sky appearing to be about the same in all cases.

The Nebula was first remarked by Herr Tempel at Venice on the 23rd of October 1859

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