A monthly look at astronomical events in the sky and on Earth
Compiled by Steve Sawyer and John Rowland
Well, it’s November already, darker evenings are coming as the days get shorter.
The Sky at night is on BBC 4, 14th November at 10 pm. As the James Webb Telescope nears its launch date. The show looks back at other famous telescopes that have enhanced our understanding of the cosmos.
Some cosmic fireworks have been taking place. I read an interesting article about FRBs (Fast Radio Bursts) with over a thousand cosmic explosions taking place over 47 days. Each explosion lasts around 1 thousandth of a second but produces as much energy as one year worth of the Sun’s total energy output. [Read more here]
There are currently 11 sunspots on the sun. Not a great deal of activity at the moment. Some very good dashboards for space weather enthusiasts can be found at Space Weather Prediction Center.
The main event taking place this month is a partial lunar eclipse. This takes place early in the morning on the 19th November. At around 6.00 am you’ll see a full moon above the western horizon and as the moon drops lower it will be eclipsed by the Earth’s shadow. In order to see this event, you’ll need a location with a clear west-northwest horizon. A nice guide to the eclipse can be found in the RMG Lunar Eclipse Guide.
The New Moon on 4th November. The Moon will be located on the same side of the Earth as the Sun and will not be visible in the night sky. This phase occurs at 21:15 UTC. This is the best time of the month to observe faint objects such as galaxies and star clusters because there is no moonlight to interfere.
On Saturday the 6th November, a very thin (4%-lit) waxing Crescent Moon may be seen very low above the southwest horizon. If you have a clear view of the southwest horizon down to ground level then this might be possible to see! (See the Crescent Moon Watch page for more details.)
Mercury can be seen in the early morning at the start of November. Look East-Southeast as the planet rises around 100 minutes before sunrise.
Evening planet which remains low after sunset. Very bright with a mag of -4.7. If you do have a clear sightline, Venus will appear as a crescent through a telescope getting thinner with each passing day.
Mars can be seen low on the horizon early in the morning. On the 11th and 10th November, Mars can be seen close to Mercury with around 1 degree of separation.
It’s very easy to observe Jupiter in the evening sky now. It’s the most prominent planet and is easily seen in the southern sky.
Evening planet, reaching highest altitude early evening.
Remains well-positioned all month. The planet is still located in Aries and is shining at mag +5.7 which means it could be visible to the naked eye with good dark skies. Uranus is still one of the best planets to observe from the UK.
Neptune is well-positioned in the south all month. An evening planet with a mag of around +7.9 so binoculars or a small telescope is required.
November 4th – 5th almost coinciding with bonfire night the Taurids Meteor Shower peaks on the 4th. The Taurids is a long-running minor meteor shower producing only about 5-10 meteors per hour. It is unusual in that it consists of two separate streams. The first is produced by dust grains left behind by Asteroid 2004 TG10. The second stream is produced by debris left behind by Comet 2P Encke.
The new moon will leave dark skies this year for what should be an excellent show. The best viewing will be just after midnight from a dark location far away from city lights. Meteors will radiate from the constellation Taurus but can appear anywhere in the sky.
On November the 17th and 18th the Leonids Meteor Shower peaks. You can expect around 15 meteors per hour at its peak. This shower is unique in that it has a cyclonic peak about every 33 years where hundreds of meteors per hour can be seen. That last of these occurred in 2001. The Leonids is produced by dust grains left behind by comet Tempel-Tuttle, which was discovered in 1865. The shower runs annually from November 6-30. It peaks this year on the night of the 17th and morning of the 18th. Best viewing will be from a dark location after midnight. Meteors will radiate from the constellation Leo, but can appear anywhere in the sky.
Deep Sky Objects (DSOs)
The star of the show for November and December must surely be M31, the Andromeda nebula (or galaxy to be more precise). In case you don’t know how to find it, the chart above should help. M31 is near the centre and almost overhead in the evening. Use the top two corner stars of the square of Pegasus, go left one star, then left one more, then up two stars, and M31 is to the right of that last star.
Many people don’t realise how big (in angular measure) M31 is. Believe it or not, it is over 3° wide. That’s six times the apparent diameter of the moon. It is also much fainter than its magnitude of 3.5 would suggest because that magnitude is spread over an area of at least 2.5 square degrees. Understand then, that you should not just point any old telescope and eyepiece combination at it at any old time and expect to see it at its best.
Firstly, don’t even think about it if the Moon is around. To give it your best shot, observe it during the first third of November or wait until the 26th and before the Moon rises.
Secondly, don’t even think about it unless the sky is really dark and the clarity is high. It doesn’t have to be cloudless if the gaps between the clouds are very dark but if there’s even a hint of mistiness or high cirrus clouds, forget it.
Thirdly, you must use a low power wide field eyepiece to get all that 3° width into the field. If you don’t, you’ll only see the central area of the galaxy. In many cases, a good pair of binoculars held really steadily (perhaps on a stand) is the best way to see this exceptional object.
Fourthly, use averted vision. Don’t look straight at it; look to one side or above or below. If you do, whilst remaining aware of the centre of the field, it will look brighter. That’s because you’re using rods (which detect dim light), which are not present in the central axis of the eye. If you’ve never used averted vision, now is the time to try it. There’s an excellent Wikipedia entry on the subject, which I recommend you read.
And finally, you won’t believe me when I tell you that in fact, in terms of the surface brightness of an extended object like M31, the highest surface brightness is achieved by using the unaided eye. In other words, M31 looks brighter with the naked eye than through any telescope. There, I knew you wouldn’t believe me! Through binoculars or a telescope, what makes you think it’s brighter and easier to see is that it’s bigger, and you’re actually seeing the brighter condensed central area.
If you think about it, the visibility of the Andromeda galaxy is about the same as the visibility of our own Milky Way. They are both spiral galaxies seen edge-on or nearly edge-on. The only difference is the distance. So if you can’t see the Milky Way arching overhead from east to west, you won’t see M31.
There’s a similar galaxy (physically) to M31 not far from it. It’s the M33 Triangulum galaxy. It’s there on the chart above. M33 is smaller and much fainter than M31 and we’re seeing it square on, so its surface brightness is even less than M31’s. It’s quite a challenge to detect it.
Finally, all the DSOs featured on the chart above are magnitude 6.0 or brighter, which means they should be easily seen even with the most modest telescope, and in many cases, binoculars. Here’s a quick summary of the best objects to go for. (Size in arcminutes.)
|Object||Type||Size / Mag.||Notes|
|M39||Open cluster||29 / 5.5||Very loose. Use binoculars.|
|M31||Galaxy||190 / 3.5||“The Andromeda Nebula”|
|M33||Galaxy||60 / 5.7||“The Triangulum Galaxy”|
|NGC752||Open cluster||75 / 5.7||“Caldwell 28”|
|M34||Open cluster||35 / 5.5||Very loose. Use binoculars.|
|M45||Open cluster||110 / 1.6||“The Pleiades”. Wonderful|
|NGC884/869||Twin open clusters||60 / 3.7 & 3.8||“The double cluster”. Superb|
Answer to October 2021’s Challenge
The challenge was to identify where we are and what the date is. The answers are:
1) At the North Pole.
2) Any of the following answers, from good to brilliant:
2119, Dec 2119 – Feb 2120, Dec 16th 2119, Jan 12th 2120, Feb 8th 2120.
For more details, please see the Answer to October 2021 Challenge pdf (2-pages).
This Month’s Challenge – Solar System Object
You are on a solar system object.
It’s a “dusky melancholy sprite” with a Cyclops eye.
It was discovered by the person who built the telescope above.
If you get lost, Polaris won’t help you; use Sabik.
Where are you?
All general comments about this What’s Up are welcome and will be published immediately after moderation. But if they give or hint at the answer to the challenge, they will be published on the 15th.
Thanks for your interest, and we wish you clear skies and good viewing. Stay safe!
Steve Sawyer and John Rowland!