Monday 25th to Sunday 31st December 2023
 

Firstly, some very exciting news for Christmas morning.  I have seen Father Christmas' flight schedule for Christmas Day and if you are up around 7am to open those presents, it should be possible to see his sleigh passing overhead.

 

Look towards the west at 7.25am and you will see the sleigh appear as a pinpoint of light, like a star that is moving.  Because he is travelling so fast, it will only take about six minutes for him to pass almost directly overhead, before disappearing to the east on his way home.  It won't be possible to see the individual reindeer though, as they are too small to show up even in the most powerful telescope.

 

When the pass has finished, turn your gaze back towards the south east to see planet Venus shining very brightly, a bit like the Christmas "Star of Bethlehem".

 
 

It will be daylight shortly afterwards, so please don't risk aiming a telescope or binoculars at the planet as you must never risk accidentally catching even a glimpse of the rising Sun through an eyepiece.

 

If you are desperate to use that telescope you received for Christmas, wait until the evening of 27th and aim it towards the east from around 7pm where there will be a bright Full Moon to observe, with the constellation of Orion that contains the red giant star Betelgeuse to the right of it.

 

 

 

Monday 18th to Sunday 24th December 2023
 

If you stay up late on the evening of Tuesday 19th, Ganymede which is Jupiter's largest moon, will be occulted or hidden by the planet.  Look towards the south west at 11.30pm and Ganymede will be just starting to disappear.  It reappears again at around 1.15am on the Wednesday morning.

 
 

Friday 22nd is the winter solstice here in the Northern Hemisphere.  This is when the Earth's north pole is at its maximum tilt away from the Sun, resulting in the shortest period of daylight hours and the Sun will be at its lowest maximum elevation above the horizon at midday.

 

If you venture outside just after midnight on the morning of Sunday 24th and look south west, there are several objects to see with the naked eye.  There will be a 91%-lit Waxing Gibbous Moon with the Pleiades open cluster of stars above it and Jupiter below, forming a straight line.  To the left of the line will be the bright red giant star Aldebaran.  Further left again you will find the constellation of Orion with the red giant Betelgeuse.  Keep going left and almost due south will be the brightest star in the night sky, Sirius.

 
 

The original Christmas "Star of Bethlehem" has been the subject of much debate over the centuries - some people believe it was a massive supernova where a star explodes, others think it was a comet and there are several theories about it actually being a close conjunction between Jupiter and Saturn that created the visual "star" effect!

 

On that note, I would like to wish everyone a peaceful Christmas and the clearest of skies for the coming year.

 

 

 

Monday 11th to Sunday 17th December 2023
 

I'll start next week's report with the evening of Tuesday 12th, when it is the turn of Ganymede to be occulted by Jupiter.  If you look towards the south east at 8pm, the Galilean moon will be just about to disappear behind the planet.

 
 

Moving on to the night of Thursday 14th into the early hours of Friday morning 15th, we have the peak of the annual Geminids meteor shower.  Around midnight, the constellation of Gemini will be located towards the south east with the familiar shape of the "Twins" looking as if one is above the other.  The radiant point of the shower, where the meteors seem to originate from, will be a little above the bright star Castor which marks the head of the top twin.

 
 

Staying with the astronomical theme of observing objects appearing to be on top of one another, at 7.30pm on Sunday 17th, a 27%-lit Waxing Crescent Moon will be sitting just below a magnitude +0.8 Saturn if you look towards the south west.

 
 

An hour and a half later, at 9pm, the Galilean moon Callisto will be directly below Jupiter's south pole if you turn your telescope towards the south.  You should be able to see all four of the Galilean moons simultaneously, forming a line stretching away from the planet.

 
 

If you try doing that, be careful as you will be making the same observation that Galileo did back in 1610, when he realised that our Solar System was "Heliocentric" with the Sun in the middle - an observation that found him to be "vehemently suspect of heresy" and placed under house arrest for the rest of his life!

 

 

Monday 4th to Sunday 10th December 2023
 

I've spoken several times recently about "transits" where one of Jupiter's moons passes in front of the planet, casting a shadow.  On the evening of Thursday 7th there is an opportunity to see the opposite effect - an "occultation" where a moon passes behind the planet and is obscured from our view.

 
Approaching 9pm, Jupiter will be located towards the south, with the constellation of Orion to the left of it and Saturn low on the horizon to the right.
 
 
At 9pm, the Galilean moon Io will be just starting to disappear behind the gas giant.
 
 

It will reappear again from behind the other side of Jupiter just after midnight.

 
 

If you would prefer an early morning, a little before daybreak, say around 6am on Saturday 9th, a 14%-lit Waning Crescent Moon will be visible towards the south east, with Venus just to the left of it, shining very brightly at a magnitude of -4.0 so an excellent chance to observe it.

 
 

Remember that the magnitude scale works back-to-front, so the more negative the figure, the brighter an object appears.  With the naked eye from a dark location, you can see down to a magnitude of +6.0 and anything fainter than that needs binoculars or a telescope.  The brightest star in the night sky, Sirius, has a magnitude of around -1.4 so it is very easy to see.  To put that into perspective, our Sun (which doesn't really count because you don't see it in the NIGHT sky) would have a magnitude of -26.  That's why you NEVER try looking at it through a telescope!

 

 

 

Monday 27th November to Sunday 3rd December 2023
 

It's a fairly quiet time for astronomical events during the coming week, so I'm going to take the opportunity to talk about something that has been in the news a lot lately - the Northern Lights or Aurora Borealis.

 

We all know that the Sun gives off loads of light, but it radiates other energy as well, including the Solar Wind that is a plasma stream of electrons and protons originating from the upper atmosphere of the Sun, an area known as the Corona.  This stream can be travelling at up to 750Km per second.

 

The Earth has a magnetic field around it known as the Magnetosphere.  When the Solar Wind hits our Magnetosphere, the wind creates disturbances in it and the resulting ionisation creates the amazing light that you see.

 
 

Magnetosphere diagram courtesy of Wikipedia

 

The disturbance is concentrated around the poles, so the visual effect is normally seen in the polar regions, but when the aurora is super strong, it can reach further down and we have a chance to observe it here in the south west of England.  Auroras around the North Pole are known as the Aurora Borealis, but there is also an Aurora Australis around the South Pole.

 
 
Aurora image courtesy of Wikipedia
 

On a totally different subject, my astronomy talk and star party at the Ham Hill Visitor Centre in December sold out very quickly, so I have agreed two more dates for the New Year.  The dates for your diary are Friday 26th January and Friday 8th March.  Booking is via the Visit South Somerset website, accessible by clicking on the images below:

 

 

Monday 20th to Sunday 26th November 2023
 

How about seeing two things at once?  Well there are a couple of opportunities to do that next week without having to stay up late.

 

Firstly, during the evening of Monday 20th, a First Quarter Moon will make a great target for your binoculars or telescope with Saturn just above and to the right of it.  If you venture outside around 6pm, the pair will be located towards the south.

 
 

By 11pm they will appear to have moved across the sky and will be disappearing below the horizon towards the south west.

 

Go outside at 6pm on Saturday 25th instead and an almost Full Moon will be located towards the east, with Jupiter just to the right of it.

 
 

The actual Full Moon occurs a couple of days later and this period is not the best for observing faint deep sky objects because a Full Moon is the ultimate source of light pollution!  The whole of November is brilliant for studying Jupiter though as it reaches a nice high elevation in the sky and is visible for most of the night, so if you can't sleep and feel the urge to whip out your telescope at 2am, the gas giant will still be there waiting for you!

 

Finally, there is one good opportunity to observe the International Space Station passing silently overhead on the early evening of Wednesday 22nd.  It will appear above the horizon to the west at 5.57pm and will be visible for five minutes before disappearing towards the east.  Sunlight reflecting off the ISS solar panels make it look like a bright star, except that it doesn't twinkle and it's moving!

 

 

Monday 13th to Sunday 19th November 2023
 

On Monday 13th, planet Uranus reaches opposition when it will be shining at its brightest.  With a magnitude of around +5.6 it could just be seen with the naked eye from a very dark location that has zero light pollution.

 

If you look towards the east around 6pm, Jupiter will be easy to spot due east, with the Pleiades open cluster of stars to the left of it.  Uranus will be located half way between the two.

 
 

It may be difficult to identify the planet amongst the background stars, so I have provided a star chart to help you select the correct pinpoint of light!

 
 

The early morning of Saturday 18th sees the peak of the Leonids meteor shower, so named because the radiant point where the meteors appear to originate from is near the head of the lion in the constellation of Leo.

 

From 1am on the Saturday morning, Leo will have risen above the horizon towards the east.

 
 

By 4am, Leo will have moved towards the south east and a very bright planet Venus will be rising towards the east with the constellation of Virgo as its backdrop.

 
 

At its peak, the Leonids meteor shower can produce up to 12 shooting stars per hour which are debris left by comet Tempel-Tuttle entering the Earth's atmosphere at speeds of up to 70 km/s.

 

 

Monday 6th to Sunday 12th November 2023
 

It looks like next week is going to be "Jupiter Week" as there are several things to spot with your telescope on what is the largest planet in our Solar System.....that's if the weather plays ball!

 

Firstly, from 10.20pm on the evening of Monday 6th, the Galilean moon Io transits the gas giant planet.  Underneath Io itself, you may be able to see the shadow that it casts on Jupiter's surface.  Around that time, Jupiter will be nicely placed towards the south east and very easy to spot because it is so bright.

 
 
 

Then from around 6pm on Friday 10th it is Ganymede's turn to transit the planet.  Because it is earlier in the evening, Jupiter will be located more to the east.

 
 
 

The transit will be finished by 7.45pm so then you could turn your telescope southwards to take a look at Saturn's rings.

 

Finally, Saturday 11th around 8.45pm is an optimum time to observe the Great Red Spot on Jupiter's surface.  Again, Jupiter will be easy to spot towards the south east, a little to the right of the Pleiades open cluster of stars.

 
 

The Great Red Spot is actually a storm in Jupiter's atmosphere that has been blowing for over 350 years with wind speeds up to 270 miles per hour.  It is about the same size as the whole of our Earth and appears to rotate around Jupiter every ten hours.  And you thought we had it bad!

 
 

Great Red Spot - Earth Comparison image courtesy of Wikipedia

 

 

Monday 30th October to Sunday 5th November 2023
 

On Friday 3rd Jupiter reaches opposition, when it will be at its brightest and shining at an impressive magnitude of around -2.8

 

By 6pm the planet will have risen above the horizon to the east and if you look to the left of Jupiter you will find the Pleiades open cluster of stars.

 
 

Aiming a telescope at Jupiter will reveal all four of its Galilean moons.  Sometimes you won't see all four of them, if one is hidden from view as it passes behind the planet.

 
 

Turn your telescope towards the south east and you will find Saturn with its dust rings.

 
 

You could even try to identify some of Saturn's numerous moons.

 
 

If instead you venture outside around 11pm on Saturday 4th, a 53%-lit waning Gibbous Moon will have risen above the horizon to the east.

 
 

Just to the right of the Moon will be the Beehive open cluster of stars, also known as M44 in the Charles Messier catalogue.  M44 is one of the closest clusters to us and it comprises around 1000 stars.  To the naked eye it will resemble a fuzzy blob, but it may be difficult to see at all without a telescope because of light pollution from the nearby Moon.