IF you look high overhead on November evenings at around 9 pm it is easy to find one of the most recognisable star patterns in the sky; the famous ‘W’ of Cassiopeia, a star pattern which rivals Orion and the Plough.
Cassiopeia lies on the opposite side of the North Star to the Plough, so when Cassiopeia is seen high up in the sky, the Plough will correspondingly be seen at its lowest point. Cassiopeia and the Plough are known as ‘circumpolar’ groups of stars, because seen from Britain they never set – they are visible in the sky throughout the year.
The letter ‘W’ of Cassiopeia is formed from five stars. Beginning at the western end, or the right hand end, we see the star beta, whose proper name is Caph, which means ‘palm’. Next comes alpha or Shedar which means ‘breast’; gamma, which has no name, marks the middle star; then comes delta whose name is Ruchbah, which means ‘knee’ and finally epsilon, which again has no name and is quite noticeably the faintest of the five stars.
Probably the most interesting of the stars of the ‘W’ of Cassiopeia is gamma, the middle star, which is one of the brightest stars to have no proper name. Gamma is a star that sometimes changes in brightness. Stars that do this are called variable stars. The study of variable stars began with the astronomers John Goodricke and Edward Pigott who lived and worked in York between 1781 and 1786. I christened them the ‘Fathers of Variable Star Astronomy’ because of the work they did.
Gamma Cassiopeia is normally about the same brightness as the other stars of Cassiopeia, apart from the fainter epsilon, but between 1932 and 1942 it became noticeably brighter than the other stars and was even brighter than the North Star. This changed the appearance of Cassiopeia considerably. It is therefore well worth keeping an eye on gamma as it is very capable of springing a surprise on us.
The Milky Way passes through Cassiopeia and anyone with a pair of binoculars can see some fantastic views of star fields in our galaxy.
In mythology, Cassiopeia is the boastful queen who upsets Neptune, the god of the sea, who then sends a monster, the Kraken to attack her land. The queen is told that the only way to save it is to have her daughter, the princess Andromeda, chained to a rock so the monster can eat her.
With Andromeda chained to a rock everything seems lost, but just at the last moment our hero Perseus, riding the winged horse Pegasus arrives on the scene. Perseus has just killed the Medusa, a creature with hair made of snakes, and so horrible that if you looked at it you would turn to stone. Luckily Perseus still has the head of Medusa with him, so he points it at the monster which then turns to stone. Perseus lands to rescue Andromeda and they marry and live happily ever after. All these characters can be seen in the autumn sky.
In November the star charts reintroduce the familiar brilliant constellation of Orion the Hunter which is visible once again, although it does not come into full view much before midnight. Also becoming more conspicuous in the east are the Pleiades or Seven Sisters and the bright red star Aldebaran in the constellation of Taurus the Bull. The star that will occupy the overhead point during winter, Capella in the constellation of Auriga the Charioteer, is also becoming more noticeable in the east. On the other hand the Summer Triangle of stars has now lost its dominance and while Vega and Deneb can still be easily seen in the west, the third member, Altair, is now more difficult to find because it is very low in the west.
The Square of Pegasus still dominates the southern sky, with Andromeda and Perseus also easy to find. This is the last month of the year when it is possible to find Fomalhaut, the most southerly of the bright stars seen from Britain, which can be found by using the two right hand stars of the square of Pegasus.
The Planets in November
The two gas giants Jupiter and Saturn that have graced our skies for the past few months are now getting very low in the south west and by early evening both will have set. To compensate, the red planet Mars will still be in the sky in the south. During October it was at its brightest and although it will fade in brightness a little during November, it will be very easy to see.
It is, however, to the morning skies that our attention should turn this month. Venus will still be seen as the very bright white dot in the sky about two hours before sunrise. However Mercury, the closest planet to the Sun, will be the main ‘star’. If you look to the south east about an hour before 1
the Sun rises you will be able to see a pinkish looking ‘star’ low in the sky. This is Mercury, by far he most difficult of the naked eye planets to see.
Meteor Showers
Following last month’s Orionid meteor shower, this month we have the unusual shower know as the Leonids, so named because the meteors appear to come from the constellation of Leo the Lion. It varies considerably because the main swarm of meteors are bunched together instead of being spread out all along the orbit. Most years around 20 meteors per hour can be seen, but the Leonids produce dramatic displays about every 33 years, the most recent being in 2003 when about 3,000 meteors per hour were observed. In 1966 an incredible 180,000 meteors were seen in an hour! The Leonids are associated with comet Temple-Tuttle. This year on the night of November 17th/18th we will probably see about 20 Leonids per hour.
Phases of the Moon for October
Full Moon 30; Last Quarter 8; New Moon 15; First Quarter 22.
On the morning of the 13th around 6 am you will be able to see the crescent moon between Venus and Mercury.
If you look to the south west on the 19th at around 5pm you will see a very nice sight in the sky as the crescent moon will be visible below both Jupiter and Saturn.
The full moon in November is known as the Frost Moon. November is the month when traditionally the first very cold nights of the year occur and frosts will be seen, heralding the coming of the winter months.
Due to the current Coronavirus situation there will be no meetings of the Earby Astronomical Society until further notice.
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