A little ramble through Pegasus the Flying Horse

 The winged horse of Greek mythology, born from the blood of Medusa after she was slain by Perseus, who can be found nearby in the sky.

The most famous feature is the great square outlined by 4 stars. Strangely and for some unknown reason the top left-hand star of the square which used to be known as delta Pegasi has now been transferred to Andromeda where it has become alpha Andromedae.

To the Arab astronomers the square of Pegasus was known as Al Dalw or the Water Bucket

The great square which covers a large area and contains surprisingly few naked eye stars, look at the square you will do well to see a dozen stars.

Alpha or Markab which means Saddle is the bottom right-hand star of the square  its magnitude is 2.5 but is believed to be variable, it is an A class star with a temperature of 9,500’C and is 133 light years away.

Beta or Scheat which means Shoulder is the top right-hand star of the square it varies in brightness between magnitude 2.4-2.7. It is a red M class giant star with a temperature of 3,500’C. The star is 196 light years away.

Gamma or Algenib which means Wing or Side is the bottom left hand star of the square with a magnitude of 2.8, lying 390 light years away. It is a B class star with a temperature of 20,000’ C

Epsilon or Enif which means Nose is 690 light years away and we see it as at magnitude 2.4, it’s an orange K class supergiant star with a temperature of 3,500’C.

Eta or Matar which means Lucky Star of Rain has a magnitude of 2.9 lying 167 light years away. It is a G class giant star with a temperature of 4,700’C.

For a large constellation Pegasus contains few nebulae or clusters, the only object that will interest us is M15 an outstandingly bright globular cluster at magnitude 6.2 which can easily be seen through binoculars. M15 at 12 billion years old it is one of the oldest known. M15 is about 33,600 light years away and is about 175 light years in diameter and contains around 100,000 stars.

                                                     www.theramblingastronomer.co.uk

A little ramble through 19th century astronomy - Mu Dorado

Nature November 2^nd 1876

Mu Doradus

This star, which was called a fifth magnitude by Lacaille at the end of 1751, and a sixth by Brisbane was observed by Moesta from February 1860 to January 1861 of 8.9m or 9m only.

Perhaps one of our southern readers will put upon record the actual magnitude of this star, the period of which as Moesta remarked would appear to be one of considerable length.

                                                      www.theramblingastronomer.co.uk

A little ramble through 19th century astronomy - gamma Centaurus in 1857

 Nature June 15^th 1876

The double star gamma Centauri

Will one of our southern readers put upon record the actual angle of position and distance of this object, to decide upon the direction and amount of motion which at present are by no means obvious?

Capt. Jacobs’ measures in December 1857 showed that the star was widening as compared to his estimates in March of the preceding year, but he found a retrograde change of angle to the amount of 7 degrees, whereas the angle of 1856 compared with Sir John Herschel’s measures of 1835-36, rather point to direct motion.

Capt. Jacobs says in 1857, “Has opened sensibly since 1853, being now an easy object, whereas then under the most favourable circumstances it could only just be discerned as not round”

                                                     www.theramblingastronomer.co.uk

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 - comet photographed from Ceylon in 1901

The comet of 1901 was photographed by Captain P B Molesworth at the Tricomali observatory in Ceylon (now Sri Lanka)  on May 13^th 1901 using a Cooke & Sons camera lens of 8.42 inch focal length. 

The comet had three tails, two slightly diverging, separated by a dark streak; the third is peculiar, as it does not diverge from the nucleus but from a point just behind it. The comet is moving  daily two degrees E N E and has caused quire a sensation among the locals. 

Molesworth was using Klein’s Star Atlas to plot the course of the comet. 

MY NOTE 

This is comet Viscara, which was discovered in Uruguay on April 12^th 1901 as a naked eye comet and at its brightest it reached magnitude 1.0. This comet was a southern hemisphere object. It faded from naked eye view on May 20^th but was visible in telescopes through until October 1901.

                                                       www.theramblingastronomer.co.uk

A little ramble through Pavonis the Peacock

 Introduced by Johann Bayer in 1603 it is one of a series of celestial birds in this region of the sky including Apus, Grus, Phoenix and Tucana. The constellation cannot be seen from Britain as it is located close to the south pole star.

In mythology the peacock was sacred to Juno, goddess of the heavens. According to legend Juno sent a creature with 100 eyes called Argus to watch over a white heifer; Juno guessed that this heifer was the form into which her husband Jupiter had turned one of illicit lovers the nymph Io.

At Jupiter’s request Mercury decapitated the watchful Argus and released the heifer. Juno place the 100 eyes of Argus on the peacock’s tail.

The Chinese also saw the constellation as a peacock and called it Joo Tseo

Alpha also known as peacock magnitude 1.9 and is a B class star  with a surface temperature of 17,000’C lying at a distance 179 light years.

The second brightest star is Beta with a magnitude of 3.4  and is an A class star with a temperature of 8,000’C and is 135 light years away.

NGC 6752 a globular cluster. It is the third brightest in the sky, with a magnitude of 5.4 after Omega Centauri and 47 Tucanae, NGC 6752 was first identified by one James Dunlop of Parramatta, Australia on 30 June 1826, who described it as an irregular bright nebula which could be resolved into a cluster of many stars, highly compressed at the centre. This corresponds with a core region densely populated with stars around 1.3 light-years in diameter,

                                                    www.theramblingastronomer.co.uk

A little ramble through 19th century astronomy - new camera equipment in France in 1876

 Nature October 12^th 1876

Dr Janssen is devising construction of an automatic photographic revolver, which will take a photograph of the Sun every hour each day of the year from sunrise to sunset. The photographs which will be taken under cloudy conditions, will be useless so far as sunspots are concerned, but they might be utilised for meteorological purposes.

The others will be kept and tabulated. The advantage of this plan it will dispense with any observer and will obtain a mechanical regularity.  A communication will be made very shortly to the Academy of Sciences on the invention which was suggested by the discussion on the Transit of Venus.

It will be set to work in the physical observatory of Dr Janssen.

                                                     www.theramblingastronomer.co.uk