with Dr David Weldrake
November gives us longer evenings, shorter nights and warmer weather. Backyard decks and backyard telescopes get greater use, with the (majority of) frosty nights behind us.
November skies provide us with a view towards the south pole of the Milky Way, our home galaxy. As the galaxy is generally shaped like a spiral-armed disc with a bulge towards the centre (a bit like two fried eggs back-to-back), looking towards the galactic south pole means we are looking through the disc outside our galaxy into intergalactic space.
As such there are very few bright stars in the November night sky, but the flip side is that we get an excellent view of other galaxies, other Milky Ways which lie at incredible distances from us.
Galaxies come in a variety of sizes, shapes, brightnesses and even colours, often with unique properties that defy understanding. A subset are known as ‘Spiral Galaxies’ (like our Milky Way), displaying a impressive set of spiral arms. They come in groups, clustered together with smaller ‘satellite’ galaxies orbiting around them, and they all move through space following pre-set paths defined at the very beginnings of the Universe.
Galaxies look like faint smudges of light through backyard telescopes if you know exactly where to look. Bigger telescopes show them better, beginning to reveal their structure and details, and there are many tens of thousands of them visible from our back gardens during November, if you are away from the glare of streelights.
Bright stars in November include yellow Alpha Centauri, low in the south. White Altair, Fomalhaut, Achenar and Canopus form a long string across the sky from the north west to the south east. Very low in the east is blue-white Rigel, the brightest star in the famous and easily-recognisable constellation of Orion.
The colours of the stars are defined by their surface temperature. Rigel is blue-white as it is very hot, 12,000 degrees, which makes it twice as hot as the surface of our Sun. It is also very large, a ball so big that more than 2 million Suns (and 2,000 billion Earths) could fit inside it. It is also extremely luminous. Rigel emits more than 120,000 times the light of our Sun.
Seen from a distance of more than 900 light years (85,000,000,000,000,000 km), it would take almost 10 billion years to arrive if we could drive there in a car.
Thankfully, we are at a safe distance from this monster of a star. The main thing for us is that Rigel’s reappearance is a sure sign that summer is just around the corner.
Chart (9pm on the 15 November) produced using the Stellarium software package
The Planets in November: Mars alone
November is very light on bright planets, with only Mars visible in the evening for the month. Mars shines as a fairly bright ‘star’ towards the west in the constellation Sagittarius. It can be identified by its reddish colour, and it moves slightly against the background stars from night to night. If you look from week to week, its movement becomes obvious.
Mars has been visible in our skies for several months now, and is slowly moving closer to the Sun as seen from Earth. It will continue to be visible for a few more months to come before it passes behind the Sun next June.
Mars is now quite distant from Earth. Through a telescope it now looks like a tiny reddish ball with hints of a polar cap and vague markings, a far-cry from its appearance and brightness when it was closest to Earth back in April. Although we can still see it for a little while yet, we have to wait until May 2016 to see it at its best again.
Early risers can see Jupiter shining high in the east before sunrise, to be seen at its best in February.
The Moon in November is at first quarter (half) phase on the 1st November, full on the 7th, at last quarter phase on the 15th and new on the 23rd. Have a look at the Moon through a pair of binoculars, you’ll be amazed at how much detail you can see.