October Skylights
You cannot fail to notice the conspicuous beacon of Jupiter dominating the evening sky over in the southeast as dusk falls. As noticeable as Jupiter is to the naked eye, through the eyepiece of a telescope it is an unforgettable sight, a bright, distinctly oblate, banded disk flanked by linear specks of light – the Galilean moons, which throw up a different configuration each night. When orientated in view, closer scrutiny may also reveal the great red spot (GRS), a huge storm-like system visible for the last 400 years, but a decent 4-inch (100mm) scope is needed to spot it. Our moon resides lower left of Jupiter on the 15th.
Saturn is also visible to the naked eye to the right of Jupiter and by mid-October resides due south at 8pm almost 20 degrees above the horizon. With an apparent magnitude of +0.5 its pearly white lustre is conspicuous in comparison to the faint stars of Capricornus, the constellation in which it resides, but feeble in comparison to Jupiter which resides at the other end of the constellation. Through the eyepiece Saturn remains a glorious spectacle, with the rings still well orientated with respect to Earth. Telescopes with an aperture of 80–100mm (3.5–4 inches) will reveal the two brightest rings: ring A (the outermost) and ring B. These are separated by the Cassini division. Saturn’s largest moon, Titan, may be seen as a speck nearby, taking just under 16 days to orbit round Saturn. Our Moon passes below Saturn on the 13th and 14th.
If you have an unobstructed SW aspect, look for Venus low to the horizon around 30-40 minutes after sunset. At magnitude -3.6 Venus should be readily visible, but this brilliance is tempered by the low altitude and lighter sky conditions present. If possible view on the 9th between 6.15 and 6.30pm to spot the young crescent moon upper right of Venus. Throughout October careful observations of Venus, approximately half an hour after sunset each day, will reveal that Venus is more or less ‘flat lining’ above the SW horizon.
Uranus resides in the southern reaches of Aries – a small crooked line of stars, visible low in the east during the evening. Technically visible to the naked eye, Uranus can be spotted with binoculars. However, a telescope of 80–100mm aperture is required to reveal the small ghostly white/green disk. Uranus reaches opposition at the beginning of November.
The outermost planet, Neptune, resides low to the SSE, located midway between the faint loop of stars in Pisces and adjoining Aquarius. Having arrived at opposition last month, Neptune (magnitude +7.7) is visible in binoculars, but in reality a telescope of 100mm aperture is required to properly identify the tiny blue/grey disk.
To read the full article, see www.eskvalleynews.co.uk
The Celestial Ocean – The ‘Winged Signpost’
We are fortunate that the night sky is home to a number of useful stellar asterisms, patterns conveniently serving as guides, aiding the amateur stargazer locate many other celestial objects and wonders. The Plough or Big Dipper (part of Ursa Major) is perhaps the most well known, but the autumn sky contains a further ‘signpost’ asterism which can be utilised for such purposes. This large stellar asterism known as the ‘Square of Pegasus’ forms the major part of Pegasus, the Winged Horse, which is now riding high in the southeast during the evening.
The constellation of Pegasus is often depicted today as the winged steed of Perseus, which sprang from the blood of the gorgon, Medusa. However in mythology Pegasus was actually ridden by another hero, Bellerophon, who was sent on a mission to kill the Chimaera, a fire-breathing monster, part lion, part snake and part goat!
The stars comprising the ‘square’ sit at the corners of a perimeter around a seemingly sparsely populated area of sky. Travelling clockwise from the top left-hand star in the square, Alpheratz, we in turn encounter Scheat, Markab and Algenib. Alpheratz is actually alpha andromeda, the main body of which extends away to the east and is the jump off point for locating the Andromeda galaxy, our sister galaxy. To accomplish this, star hop twice along the chain of stars extending away from Alpheratz, then turn 90 degrees upwards at Mirach and star hop a further two faint stars. The second of which lies close by a smudge of light, the galaxy itself! At a distance of 2.65 million light years the Andromeda galaxy is considered the most remote object visible to the unaided eye from dark and transparent skies. It is astonishing to reflect that this faint smudge of light emanates from over 300 billion suns arranged in a spiral system spanning some 160,000 light years across.
Projecting a line diagonally from Alpheratz down through Markab (alpha Pegasi), marking the bottom right star of the square, will guide the observer to a zig-zag asterism of stars representing the ‘water jar’, part of the constellation of Aquarius, the Water Bearer. According to one legend this group represents Zeus pouring down the waters of life from heaven. Several stars in Aquarius have names beginning with ‘Sad’ which in Arabic means ‘luck’ (sa’d). Continue on this baring and you run into Capricornus currently highlighted by Jupiter and Saturn.
Later in the month the most southerly first magnitude star to rise over Britain begins its short apparition. Fomalhaut marks the mouth of Pisces Austrinus, the Southern Fish, into which the waters of Aquarius pour. Conveniently, the two right-hand stars in the ‘square’ (Scheat and Markab) point down almost directly to its location just above the S horizon. Fomalhaut is located at a distance of 25 light years and has at least one planet orbiting around it. The southern fishes’ northern counterpart, Pisces, occupies a large portion of the sky below Pegasus and Andromeda but is devoid of any notable stars. According to Greco–Roman mythology Pisces was associated with Aphrodite and her son Heros, who in order to escape the monster Typhon jumped into the Nile, turning themselves into fish as they did so.
From minnows to whales, or a sea monster to be more precise, as we seek Cetus in legend said to represent the gargantuan Cracken, which was sent by Poseidon to wreak havoc on the kingdom of Cepheus. Although large in area the majority of stars in Cetus are quite faint. Alpheratz and Algenib may be used to locate the whale’s brightest member, Diphda, which marks the tail of the creature. The head, an irregular loop of faint stars highlighted by Menkar or Alpha Ceti, lies below Aries. The most celebrated object in Cetus is a variable star called Mira ‘the wonderful’ (omicron Ceti), an extraordinary pulsating red super-giant star over 300 million miles in diameter. When at maximum, as has just occurred in August, the orange hue of Mira is visible to the naked eye, its slow decline to minimum then takes seven months by which time even binoculars struggle to pick it out. The whole period takes 332 days. Scheat and Algenib point down in the general direction.
So, if you are having difficulty navigating around the autumn sky, first locate a Bear’s behind or a Winged Horse!
Whitby and District Astronomical Society are hosting a Star Party at Westerdale Village Hall on Friday 1 October from 7pm onwards. Let’s hope skies are clear!
Mark Dawson,
Whitby and District Astronomical Society
WDAS usually meets in room H1, Caedmon College, Normanby campus (Whitby College). New members most welcome.
www.whitby-astronomers.com
email: spanton33@talktalk.net
.
Saturn is also visible to the naked eye to the right of Jupiter and by mid-October resides due south at 8pm almost 20 degrees above the horizon. With an apparent magnitude of +0.5 its pearly white lustre is conspicuous in comparison to the faint stars of Capricornus, the constellation in which it resides, but feeble in comparison to Jupiter which resides at the other end of the constellation. Through the eyepiece Saturn remains a glorious spectacle, with the rings still well orientated with respect to Earth. Telescopes with an aperture of 80–100mm (3.5–4 inches) will reveal the two brightest rings: ring A (the outermost) and ring B. These are separated by the Cassini division. Saturn’s largest moon, Titan, may be seen as a speck nearby, taking just under 16 days to orbit round Saturn. Our Moon passes below Saturn on the 13th and 14th.
If you have an unobstructed SW aspect, look for Venus low to the horizon around 30-40 minutes after sunset. At magnitude -3.6 Venus should be readily visible, but this brilliance is tempered by the low altitude and lighter sky conditions present. If possible view on the 9th between 6.15 and 6.30pm to spot the young crescent moon upper right of Venus. Throughout October careful observations of Venus, approximately half an hour after sunset each day, will reveal that Venus is more or less ‘flat lining’ above the SW horizon.
Uranus resides in the southern reaches of Aries – a small crooked line of stars, visible low in the east during the evening. Technically visible to the naked eye, Uranus can be spotted with binoculars. However, a telescope of 80–100mm aperture is required to reveal the small ghostly white/green disk. Uranus reaches opposition at the beginning of November.
The outermost planet, Neptune, resides low to the SSE, located midway between the faint loop of stars in Pisces and adjoining Aquarius. Having arrived at opposition last month, Neptune (magnitude +7.7) is visible in binoculars, but in reality a telescope of 100mm aperture is required to properly identify the tiny blue/grey disk.
To read the full article, see www.eskvalleynews.co.uk
The Celestial Ocean – The ‘Winged Signpost’
We are fortunate that the night sky is home to a number of useful stellar asterisms, patterns conveniently serving as guides, aiding the amateur stargazer locate many other celestial objects and wonders. The Plough or Big Dipper (part of Ursa Major) is perhaps the most well known, but the autumn sky contains a further ‘signpost’ asterism which can be utilised for such purposes. This large stellar asterism known as the ‘Square of Pegasus’ forms the major part of Pegasus, the Winged Horse, which is now riding high in the southeast during the evening.
The constellation of Pegasus is often depicted today as the winged steed of Perseus, which sprang from the blood of the gorgon, Medusa. However in mythology Pegasus was actually ridden by another hero, Bellerophon, who was sent on a mission to kill the Chimaera, a fire-breathing monster, part lion, part snake and part goat!
The stars comprising the ‘square’ sit at the corners of a perimeter around a seemingly sparsely populated area of sky. Travelling clockwise from the top left-hand star in the square, Alpheratz, we in turn encounter Scheat, Markab and Algenib. Alpheratz is actually alpha andromeda, the main body of which extends away to the east and is the jump off point for locating the Andromeda galaxy, our sister galaxy. To accomplish this, star hop twice along the chain of stars extending away from Alpheratz, then turn 90 degrees upwards at Mirach and star hop a further two faint stars. The second of which lies close by a smudge of light, the galaxy itself! At a distance of 2.65 million light years the Andromeda galaxy is considered the most remote object visible to the unaided eye from dark and transparent skies. It is astonishing to reflect that this faint smudge of light emanates from over 300 billion suns arranged in a spiral system spanning some 160,000 light years across.
Projecting a line diagonally from Alpheratz down through Markab (alpha Pegasi), marking the bottom right star of the square, will guide the observer to a zig-zag asterism of stars representing the ‘water jar’, part of the constellation of Aquarius, the Water Bearer. According to one legend this group represents Zeus pouring down the waters of life from heaven. Several stars in Aquarius have names beginning with ‘Sad’ which in Arabic means ‘luck’ (sa’d). Continue on this baring and you run into Capricornus currently highlighted by Jupiter and Saturn.
Later in the month the most southerly first magnitude star to rise over Britain begins its short apparition. Fomalhaut marks the mouth of Pisces Austrinus, the Southern Fish, into which the waters of Aquarius pour. Conveniently, the two right-hand stars in the ‘square’ (Scheat and Markab) point down almost directly to its location just above the S horizon. Fomalhaut is located at a distance of 25 light years and has at least one planet orbiting around it. The southern fishes’ northern counterpart, Pisces, occupies a large portion of the sky below Pegasus and Andromeda but is devoid of any notable stars. According to Greco–Roman mythology Pisces was associated with Aphrodite and her son Heros, who in order to escape the monster Typhon jumped into the Nile, turning themselves into fish as they did so.
From minnows to whales, or a sea monster to be more precise, as we seek Cetus in legend said to represent the gargantuan Cracken, which was sent by Poseidon to wreak havoc on the kingdom of Cepheus. Although large in area the majority of stars in Cetus are quite faint. Alpheratz and Algenib may be used to locate the whale’s brightest member, Diphda, which marks the tail of the creature. The head, an irregular loop of faint stars highlighted by Menkar or Alpha Ceti, lies below Aries. The most celebrated object in Cetus is a variable star called Mira ‘the wonderful’ (omicron Ceti), an extraordinary pulsating red super-giant star over 300 million miles in diameter. When at maximum, as has just occurred in August, the orange hue of Mira is visible to the naked eye, its slow decline to minimum then takes seven months by which time even binoculars struggle to pick it out. The whole period takes 332 days. Scheat and Algenib point down in the general direction.
So, if you are having difficulty navigating around the autumn sky, first locate a Bear’s behind or a Winged Horse!
Whitby and District Astronomical Society are hosting a Star Party at Westerdale Village Hall on Friday 1 October from 7pm onwards. Let’s hope skies are clear!
Mark Dawson,
Whitby and District Astronomical Society
WDAS usually meets in room H1, Caedmon College, Normanby campus (Whitby College). New members most welcome.
www.whitby-astronomers.com
email: spanton33@talktalk.net
.
