Stargazing: Welcome return to dark skies 

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Torbay Astronomical Society - Credit: Submitted

Stargazing with John Stapleton of Torbay Astronomical Society: 

October sees the clocks go back an hour to GMT or Universal Time at the end of the month.

Unlike many people who do not look forward to this time of year of darker, longer nights, for astronomers this is a good thing; there are more hours of darkness, and they begin earlier in the evening so that general observations can be made within a more comfortable timeframe.

Of course, we still have to wait for specific events if they are to be seen.

The darker autumn sky therefore gives us the chance to pick out the summer sky constellations and objects against a darker background.

The increase in contrast that this provides means that objects can be seen more clearly and for longer.

The autumn constellations can also be seen at their best.

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Daylight saving time was first proposed, in this country by William Willett in 1907.

His suggestion was made in order to improve hours of productivity, provide leisure time that was not dark and save £2.5 million on fuel as people would not need to use so much coal.

Prior to the Industrial Revolution the largely agrarian society had risen and gone to bed with the Sun.

The government did not pass the Summer Time Act until 1916 when it was believed that the longer period of daylight would be beneficial to factories supporting the war effort for World War One.

During the Second World War, Britain adopted double daylight savings time and set clocks two hours ahead of GMT, again to support the war effort on the Home Front.

Between October 27, 1968, and October 31, 1971, Harold Wilson’s government adopted BST continuously in an effort to reduce the number of early morning industrial and road traffic accidents that had been occurring.

While there was a reduction in early morning accidents, the number of evening accidents significantly increased so this experiment was abandoned.

Since then many private Bills have discussed the issue of daylight savings time but all of them have wanted to change to, at best, BST throughout the year rather than stick with the one International Standard – Greenwich Mean Time, also known as Universal Time - that our country still holds.

After all, if the Sun is up and it is warm at 5.30am, why not get up and head out to work, do the required hours and come back earlier in the afternoon/evening?

Perhaps our ancestors who rose with the Sun and retired with its setting knew what they were doing after all. 

The Star Chart 

The sky will look like the chart on October 8 at 9pm and again on October 23 at 8pm. And four minutes earlier on each successive night e.g. 8.56 on October 9. 

To use the chart hold it above your head while facing south so that you can look directly from the chart to the sky.

October star chart

October star chart - Credit: Torbay Astronomical Society

Skynotes 

Please note all times given in this article are in GMT so remember to add an hour to get the time in BST. 

Sun: From the beginning to the end of the month the period of dark sky increases from 8.5 hours to over 10 hours. The longer nights allow us to view the summer constellations and the Milky Way that runs through them against a dark sky whilst also introducing the Autumn constellations and the interesting objects in them.   

Mercury: Mercury is not visible this month as it is at inferior conjunction, that is to say, it lies directly between the Earth and the Sun and so cannot be seen.  On rare occasions this results in a perfect line of sight so that we can see Mercury silhouetted against the Sun’s disc. This is known as a transit of Mercury. However this is not the case this month. The next such event will not occur until 2032. 

Venus: Venus is an evening object throughout the month, setting about 100 minutes after the Sun on the 29th. However Venus lies quite low in the sky, only 10 degrees - the width of a clenched fist at arm’s length - above the Horizon. Venus can now be seen against the background stars of the constellation of Ophiuchus. This is a large constellation that lies along the path of the planets across our sky - called the Ecliptic - but was not included as a zodiacal constellation even though some planets spend far more time in Ophiuchus than they do in some of the smaller Zodiac constellations such as Ares and Libra. Patrick Moore used to say that as there were only 12 months and 13 constellations, they had to veto one and as no-one knew what an Offyook was this is the one that was lost. 

Mars: Mars is not visible this month as it is now too close to the Sun to be observed.   

Jupiter: The largest planet rises in the east around 4.30pm on October 1 and another three hours earlier - due to the clocks changing - by the end of the month and is seen against the background stars of Capricornus. The coloured bands and zones on the surface of the planet can be distinguished with small telescopes as can the Great Red Spot, a colossal hurricane, greater in diameter than the planet Earth. The Galilean moons can be seen with a good pair of binoculars or a small - bird-spotting - telescope. DSLR images of the planet will also pick up the moons. These moons orbit Jupiter such that we sometimes see them pass between the Earth and the giant planet along our line of sight.  Watch out for small black dots seen against the surface of Jupiter itself. The moons Ganymede and Callisto will cast their shadows onto Jupiter at the same time, around 8pm, on October 4 and October 21, Io and Callisto begin to transit at 2am.  

Saturn: The ringed planet can also be found against the stars of Capricornus, rising in the East around 3.45pm on October 1 and another three hours earlier by October 31, which means it is already in the sky when darkness falls. Saturn reaches 21 degrees altitude, the span between your thumb and little finger at arm’s length, this month. The rings are beginning to open out, from our point of view and are consequently becoming brighter. Saturn’s largest moon, Titan, can be seen above and to the right of the planet with a good pair of binoculars or a small telescope. Below is an image taken by Simon with his telescope from Paignton.

Uranus and Neptune: Uranus is visible all night long throughout October and is seen against the background stars of Aries and close to the Pleiades star cluster.  At magnitude 5.8 it is visible in binoculars. Look for a tiny greenish disc compared to the pinpoints which are the stars. Neptune is seen against the background stars of Aquarius - below the asterism known as the Square of Pegasus. At magnitude 7.8 it will require large binoculars or a small telescope to find it. Neptune displays a smaller and truly blue disc compared to that of Uranus although it will appear only as a bluish star to most small instruments  

Meteor shower: There are two meteor showers due in October. The first, on October 8, is the Draconids. These are characteristically slow-moving meteors. There are only around four or four an hour but the skies will be dark as there is no Moon at that time. The second shower is the Orionids, occurring between October 15 and October 29 with a peak on October 21. These are relatively fast-moving meteors although still only up to 10 an hour. The light of the Full Moon will drown out some of the fainter meteors. The Orionids are interesting because they are formed from the debris left behind in the wake of Comet Halley.

Comet: There are no bright comets expected this month. 

The New Moon occurs on October 6 with First Quarter on October 13, Full Moon then follows on October 20 and Last Quarter on October 28.

Data supplied by Simon Harding, Observations Secretary Torbay Astronomical Society

Diary dates 

The next meetings of the Torbay Astronomical Society, complying with the current Covid regulations, will be held at Torquay Boys' Grammar School, Shiphay Manor Drive TQ2 7EL.

On October 7, an observational evening will be held in Room PL4 and the observatory, weather permitting, when members will be delighted to provide views of the objects discussed in this article. In the event of bad weather, short talks and videos will be presented alongside informal discussion and an opportunity to get to know the society.

And on October 21 Graham Bryant of the Hampshire Astronomical Group will give a talk entitled 'A Month to Save the Hubble' describing the problems that had to be overcome in order to ensure the continued operation of this valuable, and now iconic, instrument.

Talks will also be available online via Zoom. For details, contact the TAS secretary on astrosecretary@gmail.com. Visitors and prospective members especially welcome.