Winter has arrived

Ken Kennedy, of Dundee Astronomical Society, tells us what to look for in the November sky. “Winter is making its entrance,” he says. “During summer the constellations are difficult to see because of the brightness of our northern sky, but now that it is dark by 6pm we can see the glory of the winter constellations.

“Pegasus is still high towards the south followed by Perseus and Auriga with its bright star, Capella. By about 10pm, Gemini will be seen rising over the eastern horizon. If your eastern horizon is low you may catch sight of Betelgeuse and the three stars of Orion’s belt as they rise, then we will know that winter has indeed arrived.

“Given a reasonably cloud free day, an unusual event takes place on November 11. This is a transit of the planet Mercury across the face of the sun. This only takes place around 13 times each century when the small dark spot of the planet can be seen to slowly cross the sun.

“Anyone wishing to see this event should be warned of the risk to eyesight if observation is attempted without suitable protection. However, the disc of Mercury as it crosses the sun is only about 10 arc seconds in diameter and it is unlikely to be seen with the unaided eye.

“A telescope modified to project the image of the sun is probably the safest way to view the event or a telescope fitted with a suitable filter over the objective lens, not one which can be inserted into an eyepiece.

“Mercury will make contact with the sun’s limb at 12.35pm and will cross to near the centre at 3.20pm. By this time the sun will only be at an elevation of 5° towards the south-west. The sun will set at 4.10pm but Mercury will remain on its face until 6.04pm.

“The Leonid meteor shower reaches a peak at around 11pm on November

17. The last quarter moon will tend to interfere by hiding many of the meteors because of its brightness which will be at its worst after midnight. On an average year there is unlikely to be more than 15 Leonids seen per hour, but in exceptional years there have been ‘meteor storms’ when, for a short time, thousands per hour have been recorded.

“Such a display was seen in 1966 but it is difficult to predict when the next Leonid storm may occur and it is very unlikely that it will be this year.

“Mercury moves westwards towards the sun and crosses its face on November

11. It then continues westwards to be seen low in the south-east before sunrise from around the 20th.

“Venus is not well placed for observation but may just be seen low in the south-west after sunset from around the 17th until the end of November. Jupiter is all but lost in the twilight of the setting sun during November but will be close to Venus on the 23rd/24th of the month. Saturn can be found low in the south south-west after sunset. The planet will set at around 7pm.

“The moon is at first quarter on the 4th, full on the 12th, last quarter on the 19th and new on November 26.”